Oleh Mas Edy

On shore 16 July 2010

Nah ini sama-sama di sebut V.C.F tetapi bukan VCF (Volume Corection Factor) tetapi Convertion Vactor jadi beda tipis aja ada V.C.F corection dan V.C.F convertion ok. taulah  arti nya dalam bahasa daera masing2. he2.

Jadi, VCF (Volume Convertion Factor) adalah suatu angka atau factor perkalian untuk mendapatkan Barrels@ 60 F , Gallons dan Gallons ke Liter@ 15°C.

Misal nya anda sounding minyak dalam tanki lalu dengan tabel sudah anda koreksi trim, kemiringan dan hasil nya adalah= 3,400 kilo liter. Kemudian sudah di koreksi dengan perkalian untuk mendapatkan Net kilo liter sehingga anda mendapatkan hasil seperti ini

Gross KL = 3,400

V.C.F       = 0.980206 x

Net KL    = 3,332.7

Ok, anda sudah sampai pada Net kilo liter sekarang lanjutkan dengan mencari Barrels@ 60 F

Net KL              = 3,332.7

V.C.F                =  ?         x

Barrels@ 60 F  =  ?

Yang perlu di ketahui adalah: Density pada 15°C

Bagaimana kita mencari daftar 52… Untuk menemukan Barrels ?

Diketahui:

• Density pada 15°C = 0.7251 (sumber dari table 53)

Untuk mengetahui Nilai Daftar 52 ? seperti gopean di bawa ini.

Jadi V.C.F (Daftar 52) adalah: 6.294  ok, tinggal di masukan, gampang kan???

Net KL    = 3,332.7

V.C.F       =  ?         x

Barrels    =  ?

Di pertamina suda di tetepkan daft 52 untuk konversi ke barrels sbb:

• Untuk premium daft 54 nya adalah: 6.294
• Untuk kerosine daft 54 nya adalah: 6.293
• Untuk solar daft 54 nya adalah: 6.293

Dibawa ini salah satu contoh cara lain (sama aja, beda style aja) penyelesaian yang di sajikan menurut buku daftar ASTM  ( American Society For Testing Materials ) selamat mencoba. sukses..

Postingan lain yang mungkin berhubungan:

• July 16, 2010 -- Cara mendapat WCF (Weight Convertion Factor), membuka ASTM table 57
• July 16, 2010 -- Density reduction, ASTM table 53
• July 16, 2010 -- Cara mendapat VCF (Volume Corection Factor), membuka ASTM table 54
• November 5, 2009 -- Menentukan Transport Lost
• November 5, 2009 -- Perhitungan Muatan Minyak BB
• January 24, 2009 -- MUATAN BERBAHAYA (DANGEROUS GOODS)
• December 15, 2009 -- Ukur dan Hitung Minyak
• January 19, 2009 -- Penanganan Muatan Tanker
• February 15, 2010 -- Liquefied natural gas, LNG
• February 3, 2010 -- Mualim II Emergencies and Cargo handling

Oleh Mas Edy

On shore 16 July 2010

WCF (Weight Convertion Factor) adalah suatu angka atau factor perkalian untuk  mendapatkan Long Tons dan Short Tons.

Ok, jadi kita suda selesaikan perhitungan sampai pada menetukan Barells, kalo anda membaca postingan saya berurutan berarti sedikit nyambung.

Misal nya anda sounding minyak dalam tanki lalu dengan tabel sudah anda koreksi trim, kemiringan dan hasil nya adalah= 3,400 kilo liter. Kemudian sudah di koreksi dengan perkalian untuk mendapatkan Net kilo liter sehingga anda mendapatkan hasil seperti ini

Gross KL = 3,400

V.C.F       = 0.980206 x

Net KL    = 3,332.7

Anda sudah mendapatkan NET KL pada temperatur 15°C sudah cukup data untuk bisa konversi ke berbagai macam satuan Barrels, Long Tons, Short Tons, Metric Tons.

anda juga sudah mencari Barrels@ 60 F sudah okelah ya, sekarang lanjutkan dengan mencari Long Tons, Bagaimana kita mencari W.C.F untuk mendapatkan Long Tons

Ikuti langkah2 berikut ini.

Yang perlu di ketahui adalah Density pada 15°C. ya cukup Density

Diketahui:

Density pada 15°C = 0.7251 (sumber dari table 53)

Silahkan menyimak gambar berikut ini.

• Yang di cari adalah: 0.7251

ada nggak di kolom table yang nyambung dengan 0.7251 ? Gk ada, maka kita interpolasi sbb:

• Selisih antara 0.7250 dan 0.7260 adalah: 10
• Selisih antara 0.7125 dan 0.7134 adalah: 9
• Maka interpolasinya adalah: 1/10 x 9 = 0.9

0.7125

         0.9 +

0.71259

• Jadi 0.7251nya adalah = 0.71259 betul?

Artinya nilai W.C.F (daft 57) adalah: 0.71259

Tinggal masukin angka W.C.F  pada perkalian bersusun dibawa ini dan mendapatkan Long tonsnya dan selesai. Gampang kan?

Net KL              = 3,332.7

W.C.F               =  ?         x

Long Tons        =  ?

Dibawa ini salah satu contoh cara lain (sama aja, beda style aja) penyelesaian yang di sajikan menurut buku daftar ASTM  ( American Society For Testing Materials ) selamat mencoba. sukses..

lupa lagi trus dari Long Tons mau ke Metric Tons maka seperti ini copi paste yang dari atas ya di tambain ke bawa lagi jadi :

Net KL              = 3,332.7

W.C.F               =  ?         x

Long Tons        =  ?

Coefisien         = 1.01605 x     (jangan taya dari mana ini suda ketetapan)

MT                   =

• maka metric ton ketemu deh… t rus lagi nih misal nya anda tidak ingin ke Long Ton tapi mau langsung ke Metric Tons. maka cukup sampai dulu di Net KL setelah itu buatlah seperti ini :
•  

Net KL              = 3,332.7

W.C.F               =  ?         x ( Density – 0.0011) Weight Correction Factor 

Metric Tons        =  ? dapat deh Metric Tons nya.

Sekian.. selesai.

Postingan lain yang mungkin berhubungan:

• July 16, 2010 -- Cara mendapat VCF (Volume Convertion Factor), membuka ASTM table 52
• July 16, 2010 -- Density reduction, ASTM table 53
• July 16, 2010 -- Cara mendapat VCF (Volume Corection Factor), membuka ASTM table 54
• November 5, 2009 -- Menentukan Transport Lost
• November 5, 2009 -- Perhitungan Muatan Minyak BB
• January 24, 2009 -- MUATAN BERBAHAYA (DANGEROUS GOODS)
• December 15, 2009 -- Ukur dan Hitung Minyak
• January 19, 2009 -- Penanganan Muatan Tanker
• February 15, 2010 -- Liquefied natural gas, LNG
• February 3, 2010 -- Mualim II Emergencies and Cargo handling

Oleh Mas Edy

On Shore 16 July 2010

Awal dari perhitungan muatan menggunakan daftar  ASTM table hitung muatan tanker adalah membuka daftar ASTM table 53 ini.

Daftar 53 ASTM table adalah untuk mencari / menemukan Density yang kita ambil/observasi menggunakan gelas ukur di tanki kapal pada suhu normal saat itu di jetty ke dalam ingat kedalam suhu/temperature 15°C.

Bagaimana kita mencari daftar 53…?? Contoh seperti gopean di bawa ini.

Diketahui:

Observasi Density = 0.711

Observasi Temperature= 32°

Gampang kan,, hasil nya adalah density pabila temperature cargo 15°C adalah : 0.7251

Nilai ini akan kita gunakan untuk mencari daftar 54. Ingat tanpa nilai ini kita tidak dapat mencari daftar 54, daft 52 dan daftar 57.

Dibawa ini salah satu contoh cara penyelesaian Daftar 53 yang ada dalam buku daftar ASTM

Postingan lain yang mungkin berhubungan:

• July 16, 2010 -- Cara mendapat VCF (Volume Convertion Factor), membuka ASTM table 52
• July 16, 2010 -- Cara mendapat WCF (Weight Convertion Factor), membuka ASTM table 57
• July 16, 2010 -- Cara mendapat VCF (Volume Corection Factor), membuka ASTM table 54
• November 5, 2009 -- Menentukan Transport Lost
• November 5, 2009 -- Perhitungan Muatan Minyak BB
• January 24, 2009 -- MUATAN BERBAHAYA (DANGEROUS GOODS)
• December 15, 2009 -- Ukur dan Hitung Minyak
• January 19, 2009 -- Penanganan Muatan Tanker
• February 15, 2010 -- Liquefied natural gas, LNG
• February 3, 2010 -- Mualim II Emergencies and Cargo handling

Oleh Mas Edy

On shore 16 July 2010

VCF (Volume Corection Factor) adalah suatu angka atau factor perkalian untuk mendapatkan net volume dalam kilo liter. Jadi misal nya anda sounding minyak dalam tanki lalu dengan tabel sudah anda koreksi trim, kemiringan dan hasil nya adalah= 3,400 kilo liter. Ini sebenar nya masi gross kilo liter belum di sebut neto atau volume bersih.

Mengapa? karena material di bumi sangan rentang berubah dengan kondisi suhu atau temperature apalagi bahan cair. Maka standar perhitungan material benda cair di satukan di seluruh dunia harus satu standar yaitu di hitung pada suhu/temperature 15C. Jadi mau anda dimana aja suhunya panas atau dingin supaya tidak merugikan pihak lain ya harus di konversi ke dalam temperature 15°C.

Contoh Soal

Carilah Volume muatan 3 400 000 liter ( 3,400 KL) pada temperature 15°C ?

Penyelesaiannya:

Kita akan mencari V.C.F dengan membuka daftar tabel 54

Yang perlu di ketahui dalam membuka tabel ini adalah density @15°C dan suhu atau temperature observasi cargo saat itu.

Contoh sebagai berikut:

Density pada 15°C = 0.7251 (sumber dari table 53)

Observasi temperature= 32°C

Silahkan menyimak baik2 potongan salah satu halaman tabel di bawa ini.

Yang kita cari adalah: 0.7251 ada ngak di kolom table yang nyambung dengan 0.7251 ? Gk ada, maka kita interpolasi sbb:

Selisih antara 0.7250 dan 0.7300 adalah: 50 betul?

Selisih antara 0.9802 dan 0.9805 adalah: 3 ( aturan menulis nya 0.0050 dan 0.0003 tetapi karena saya anggap lebih mudah untuk di pahami apabila tidak berdereet banyak angka di belakang koma)

Maka interpolasinya adalah 1/50 x 3 = 0.06

0.9802

         0.06 +

0.980206

Jadi 0.7251 nya adalah = 0.980206 betul? Tetapi apabila pihak Consegnee tidak mempermasalakan menggunakan hanya 4 digit decimal maka hasil interpolasi kita tadi bulatkan menjadi seperti 0.9802 saja. Ok, kita abaikan pengandayain di atas artinya nilai V.C.F (Daftar 54) adalah: 0.980206 dari nilai ini kita akan mendapatkan NET KL @ 15° dengan susunan perkalian:

Gross KL = 3,400

V.C.F       = 0.980206 x

Net KL    = 3,332.7

Jadi Volume muatan 3 400 000 liter ( 3,400 KL) pada temperature 15°C

adalah: 3,332,700 liter ( 3,332.7 KL) gampang kan.. ialah kalo belum tau ya susah.. uda tau gampang aja.

Dibawa ini salah satu contoh cara lain (sama aja, beda style aja) penyelesaian yang di sajikan menurut buku daftar ASTM  ( American Society For Testing Materials ) selamat mencoba. sukses

Postingan lain yang mungkin berhubungan:

• July 16, 2010 -- Cara mendapat VCF (Volume Convertion Factor), membuka ASTM table 52
• July 16, 2010 -- Cara mendapat WCF (Weight Convertion Factor), membuka ASTM table 57
• July 16, 2010 -- Density reduction, ASTM table 53
• November 5, 2009 -- Menentukan Transport Lost
• November 5, 2009 -- Perhitungan Muatan Minyak BB
• January 24, 2009 -- MUATAN BERBAHAYA (DANGEROUS GOODS)
• December 15, 2009 -- Ukur dan Hitung Minyak
• January 19, 2009 -- Penanganan Muatan Tanker
• February 15, 2010 -- Liquefied natural gas, LNG
• February 3, 2010 -- Mualim II Emergencies and Cargo handling

On shore, 21 January 2010

‘International Safety Management (ISM) Code means the International Management Code for the safe Operation of Ships and for Pollution Prevention

The purpose of ISM Code is:

* To ensure Safety at Sea

* To prevent human injury or loss of life

* To avoid damage to the environment and to the ship.

SOLAS adopted the ISM Code in 1994 and incorporated it into chapter IX. By 1998 much of the commercial shipping community was required to be in compliance with the ISM code. By 2002 almost all of the international shipping community was required to comply with the ISM Code.

In order to comply with the ISM Code, each ship class must have a working Safety Management System (SMS). Each SMS consists of the following elements:

* Commitment from top management

* A Top Tier Policy Manual

* A Procedures Manual that documents what is done onboard the ship

* Procedures for conducting both internal and external audits to ensure the ship is doing what is documented in the Procedures Manual

* A Designated Person to serve as the link between the ships and shore staff

* A system for identifying where actual practices do not meet those that are documented and for implementing associated corrective action

* Regular management reviews

Another part of the ISM is the mandatory Planned Maintenance System which is used as a tool maintaining the vessel according to the specified maintenance intervals.

Each ISM compliant ship is inspected regularly by classification society to check the effectiveness of their SMS. Once classification society verifies the SMS is working and effectively implemented, the ship is issued a Safety Management Certificate. Comments from the classification society and from the ship are incorporated into the SMS by headquarters.

Postingan lain yang mungkin berhubungan:

• July 11, 2009 -- Minimum Under Keel Clearance
• February 5, 2010 -- Mualim II Sea watch
• January 18, 2010 -- Bahaya – Bahaya Minyak
• December 15, 2009 -- Ukur dan Hitung Minyak
• August 23, 2009 -- Masters` Standing Order
• August 21, 2009 -- Calling the Master
• June 26, 2009 -- Steering gear: Testing and drills
• June 26, 2009 -- Plan Maintenance System (PMS)
• January 24, 2009 -- MUATAN BERBAHAYA (DANGEROUS GOODS)

On shore, 20 January 2010

MARPOL POLLUTION – 73/78

Marpol contains 6 annexes, concerned with preventing different forms of marine pollution from ships:

Annex I: Prevention of pollution by oil

Annex II: Control of pollution by noxious liquid substances

Annex III: Prevention of pollution by harmful substances in packaged form

Annex IV: Prevention of pollution by sewage from ships

Annex V: Prevention of pollution by garbage from ships

Annex VI: Prevention of Air Pollution from Ships

1. Annex I : Peraturan pencegahan pencemaran yang ditimbulkan oleh minyak (Oil) in bulk.

2. Annex II : Peraturan pencegahan pencemaran yang ditimbulkan oleh cairan berbahaya dalam bentuk curah ( Noxious liquid substances in bulk )

3. Annex III : Peraturan pencegahan pencemaran yang ditimbulkan oleh Zat – Zat berbahaya dalam kemasan ( Harmfull substances in package )

4. Annex IV : Peraturan pencegahan pencemaran yang ditimbulkan oleh pembuangan kotoran ( Sewage )

5. Peraturan pencegahan pencemaran yang ditimbulkan oleh Sampah ( Garbage ).

6. Peraturan pencegahan pencemaran yang ditimbulkan oleh Pencemaran udara ( Air pollution )

Isi dalam MARPOL bukan melarang pembuangan zat-zat pencemar ke laut, tetapi mengatur cara pembuangan nya. Agar dgn pembuangan tersebut laut tidak tercemar ( rusak ), dan ekosistim laut tetap terjaga.

Seperti pada Annex I , kapal masih membuang minyak kelaut dgn ketentuan :

· Konsentrasi minyak harus < 15 ppm (part per million). Kapal dalam keadaan berlayar, lokasi pembuangan > 12 mil laut dari pantai terdekat

· Tiap 30 liter minyak harus di buang secara merata sepanjang 1 mil ( 30 ltr/mil ). Kapal dalam keadaan berlayar, lokasi pembuangan > 50 mil laut dari pantai terdekat.

Pembuangan keluar kapal, pada umumnya hanya di perbolehkan dilaut. Tetapi tidak di laut SPECIAL. Ini tidak di perbolehkan. Yang termasuk dalam laut special adalah:

· Mediterranean sea

· Baltic sea

· Black sea

· Red sea

· Gulf area

· Gulf of Aden

· Antartic

· North west European waters & North sea

Peralatan untuk membantu cara pembuangan dan untuk pengawasan dalam pelaksanaan Marpol:

1. ODME

2. CWS

3. Oil / Water Interfance Detector

4. Incinerator

5. – Oil Record Book Vol I. untuk kamar mesin. Vol II. Untuk Bag deck.

- Cargo Record Book utk Chemical tanker

- Garbage Record Book.

6. SOPEP ( Ship Oil Pollution Emergency Plan )

MARPOL 73-78 signatories

Marpol 73/78 is the International Convention for the Prevention of Pollution From Ships, 1973 as modified by the Protocol of 1978. ("Marpol" is short for marine pollution and 73/78 short for the years 1973 and 1978.)

Marpol 73/78 is one of the most important international marine environmental conventions. It was designed to minimize pollution of the seas including dumping, oil and exhaust pollution. Its stated object is: to preserve the marine environment through the complete elimination of pollution by oil and other harmful substances and the minimization of accidental discharge of such substances.

The original MARPOL Convention was signed on 17 February 1973, but did not come into force. The current Convention is a combination of 1973 Convention and the 1978 Protocol. It entered into force on 2 October 1983. As at 31 December 2005, 136 countries, representing 98% of the world’s shipping tonnage, are parties to the Convention.

Postingan lain yang mungkin berhubungan:

• June 1, 2009 -- Menghadapi Vetting Inspection & Oil Major, Download Ship Inspection Report (SIRE) Programme

Oleh: Mas Edy

On shore, 19 January 2009

Selang pemuatan harus sesuai spesifikasi standar penguasa nasional seperti British Standards Institution (BS 1435) atau sesuai rekomendasi OCIMF.

Selang harus di gunakan sesuai fungsinya, untuk penggunaan biasa ada tiga macam/tipe:

# R – rough bore, adalah selang yang di perkuat dengan kawat di gunakan untuk penggunaan berat (heavy ducy), utk sub marine dan floating adalah R X M.

# S – smooth bore, Selang yg tidak di perkuat dgn lilitan kawat, di gunakan utk keperluan lebih ringan ( lighter) utk floating & sub marine adalah S X M.

# L – light weight, untuk keperluan-keperluan ringan misalnya bunkering.

Selang tidak boleh digunakan melebihi klafikasinya. Klafikasi selang adalah berdasarkan besarnya tekanan atau besarnya kecepatan aliran (flow velocity). Sesuai spesifikasi OCIMF maka;

L & S dengan flow velocities 12 m/scc (40 feet / sec)

R dengan flow velocities 15 m.scc (50 feet / sec).

TESTING SELANG

Testing harus dilaksanakan secara berkala dan

terus menerus sesuai rekomendasi OCIMF yang tercantum.

Penyimpanan

Harus di simpan ditempat yang baik yaitu dingin, gelap, kering dgn sirkulasi yang cukup, di service setelah di simpan ± 2 bulan, hal ini sesuai dengan rekomendasi OCIMF.

Berat selang

Untuk CBM berat kira – kira pada daftar dalam ton (termasuk fitting, bui pengapung dan pick up, penuh minyak SGO, 850, dgn tinggi angkatan 7,5 m diatas deck saat kapal kosong.

Random Posts

• May 8, 2009 -- JENIS-JENIS VALVE ATAU KERANGAN DIATAS KAPALTANKER
• February 3, 2009 -- Daftar istilah & singkatan2 navigasi
• January 19, 2009 -- Daftar Istilah Perkapalan
• August 20, 2009 -- TT. Teluk Kabung, Padang
• February 18, 2009 -- Jenis-jenis awan
• June 27, 2009 -- Auto to Manual change over procedures
• January 21, 2010 -- International Safety Management Code
• May 29, 2009 -- The Mariners Hanbook NP100
• February 17, 2010 -- Distance table online
• July 16, 2010 -- Cara mendapat VCF (Volume Corection Factor), membuka ASTM table 54

On board, 15 December 2009

Sumber loss

Loss yang bersifat Fisik

Loss yang bersifat Semu

Sifat Minyak

Minyak bumi mempunyai titik didih yang sangat banyak yaitu dari titik didih 25 C s/d 500 C.

Selain senyawa hydrocarbon, dalam minyak bumi terdapat senyawa sulfur, metal, nitrogen, air dll.

Minyak sukar di ukur volumenya dengan tepat karena sangat rentan berubah pada perubahan suhu dan bentuk tanki.

Pengambilan Contoh Minyak dari Tanki

Composite spot

Middle spot

All-levels

Running sample

Sample cocks

Pemeriksaan Contoh Minyak

Dengan menggunakan Hydrometer, disesuaikan pada suhu 15 C.

Untuk minyak yang lebih kental dan hitam diadakan koreksi miniskus yang tepat.

Hasil pengukuran dengan hydrometer yang di laksanakan pengukurannya mendekati suhu minyak yang sebenarnya.

Ketepatan pengukuran density sangat di perlukan untuk dapat di konversi ke volume standard 15C.

Density dapat menentukan kualitas crude.

Density cairan merupakan berat massa tersebut dalam kilogram dengan volume dalam liter pada suhu standard (15C)

SG merupakan perbandingan antara berat suatu massa dalam suatu volume tertentu pada suhu 60 F dengan berat massa air murni pada volume yang sama dengan suhu yang sama

Nilai observed merupakan hasil pemeriksaan pada suhu saat pemeriksaan, yang suhunya dapat berbeda beda.

Ketelitian Peralatan : Alat Ukur Manual

Alat pengukuran level cairan.

Alat pengukuran air bebas.

Alat pengukuran suhu.

Alat pengambilan sample.

Alat pengukuran density.

Ketelitian SDM

SDM pelaksana sangat berperan dalam proses arus minyak.

Tertib Administrasi

R1 (Loading loss) sebagai cermin kinerja pengirim.

R2 (Transport loss) sebagai cermin kinerja pengangkut.

R3 (Discharge loss) sebagai cermin kinerja penerima.

R4 (Supply loss) merupakan cermin kerjasama korporat tiga pihak tersebut.

Sistimatis Pengukuran Minyak

Pengukuran Refference Depth untuk mengetahui apakah tidak ada botom fluktuasi.

Pengukuran ketinggian cairan sampai mendapatkan angka yang identik (Selisihnya < 3 mm).

Pengukuran air bebas (sama seperti point 2).

Pengukuran temperature minyak dalam tanki.

Pengambilan Sample minyak.

Pengukuran density minyak dan temperaturnya.

Pengukuran temperature minyak dalam tanki

> 5 M = 3 X

1 M di bawah permukaan cairan.

Dipertengahan tinggi cairan.

1 M di atas dasar tanki.

3M s/d 5 M = 2 X

1 M di bawah permukaan cairan.

1 M di atas dasar tanki.

< 3 M= 1 X

Di pertengahan tinggi cairan.

Pengambilan Sample minyak

> 5 M = 3 X

5/6 tinggi cairan

3/6 tinggi cairan

1/6 tinggi cairan

3 M s/d 5 M = 2 X

¾ tinggi cairan

¼ tinggi cairan

< 3 = 1 X

Di tengah tengah tinggi cairan

Pengukuran density minyak dan temperaturnya

Gelas ukur / mattglass pada tempat datar dan rata.

Terhindar dari tiupan angin.

Pembacaan Tegak Lurus.

3 X sample: 1/3 bagian dari tiap-tiap sample

2 X sample : ½ bagian dari tiap-tiap sample.

1 X sample : Seluruhnya di tuangkan ke gelas ukur

Peralatan Standard

A. Innage Tape (Dipp Tape)

ASTM D. 1085 – API. 2545

B. Water Stick Bar / Bob runcing

ASTM D. 1085 – API. 2545

Cup Case / Flushing Case Assembly

(Temperature Measurement)

ASTM D. 1086 – API. 2543

Weighted Beaker

ASTM D. 270 – API 2546

Hydrometer

ASTM D. 1298 – API. 2547

Menyiapkan alat ukur, formulir pencatatan, tabel tanki dan ASTM

Alat sounding yang sesuai dan terbaca.

Density meter (15 C) sesuai dengan Grade.

Thermometer Luar.

Gelas Ukur.

Thermometer dalam.

Botol Sample.

Pasta Air dan Minyak.

Formulir Pencatatan.

Tabel Kalibrasi Kapal.

Tabel ASTM IP D 1250

Alat Hitung / Calculator.

Langkah langkah Pengukuran

Catat Draft Depan, Tengah dan Belakang.

Catat Hell.

Lakukan Pengukuran ullage / sounding untuk cairan minyak dan free water sesuai dengan peraturan pada setiap tanki.

Lakukan pengambilan sample untuk pengukuran density dan temperatur observe sesuai dengan peraturan pada setiap tanki.

Lakukan pengukuran density dan temperatur observe sesuai dengan peraturan pada setiap tanki.

Lakukan pengukuran temperatur tanki sesuai dengan peraturan pada setiap tanki.

Menghitung Nett Volume Observe

Menghitung Trim Kapal

Menghitung koreksi ullage / sounding & koreksi hell untuk cairan minyak dan free water pada setiap tanki dengan menggunakan tabel kalibrasi kapal.

Menghitung gross volume observe setiap tanki berdasarkan angka ullage / sounding yang telah di koreksi dengan menggunakan tabel kalibrasi kapal.

Menghitung free water volume setiap tanki berdasarkan angka ullage / sounding yang telah di koreksi dengan menggunakan tabel kalibrasi kapal.

Menghitung Nett Volume Observe setiap tanki

= Gross Volume Observe – Free Water Volume

Menghitung Volume ( KL 15 C )

Menghitung dan menentukan angka density 15 C berdasarkan angka hasil pengukuran density dan temperatur observe pada setiap tanki dengan menggunakan tabel 53 ASTM IP D 1250.

Menghitung dan menetukan angka Volume Correction Factor (VCF)berdasarkan angka density 15 C dan temperatur tanki yang telah di peroleh dengan menggunakan tabel 54 ASTM D 1250.

Menghitung Volume KL 15 C pada setiap tanki.

= Nett Volume observe X V Corr Factor

Menghitung Volume dalam Barrel 60 F

Menentukan angka Volume Conversion Factor (VCF) berdasarkan angka density 15 C yang telah di peroleh dengan menggunakan tabel 52 ASTM IP D 1250 pada setiap tangki.

Menghitung Volume Barrel 60 F

= Volume KL 15 C X Vol.Conv.Factor

Menghitung Berat dalam Long Ton

Menghitung dan menentukan angka Weight Conversion Factor (WCF) berdasarkan angka density 15 C yang telah di peroleh dengan menggunakan tabel 57 ASTM IP D 1250 pada setiap tangki.

Menghitung Berat dalam Long Ton :

= Volume KL 15 C X Weight Conv.Factor

Menghitung Berat dalam Metric Ton

Menghitung dan menetukan angka Weight Conversion Factor (WCF) berdasarkan density 15 C yang telah di peroleh dengan menggunakan tabel 56 ASTM IP D 1250 pada setiap tangki.

Menghitung berat dalam Metric Ton :

= Volume KL 15 C X Weight Conv.Factor

Atau

Menggunakan angka WCF dari LT ke Metric Ton dengan menggunakan tabel 1 ASTM IP D 1250

= Long Ton X 1.01605

Vessel Experince Factor

Dengan Metoda IP PMM Part XVI Appendix C

Dengan Metoda API MPMS Chapter 17

Voyage yang tidak boleh di perhitungkan :

Voyage pertama setelah melaksanakan docking.

Pengoperasian tidak di muati full.

Voyage di mana B/L berdasarkan angka ship figure.

Voyage pertama apabila ada perubahan capasitas yang berdampak pada jumlah muatan yang di angkut.

Voyage yang hanya di isi kurang dari 80% kapasitas.

Istilah – Istilah

TCV:Total Calculated Volume

VLR:Vessel Load Ratio

VDR:Vessel Discharge Ratio

VEFL:Vessel Experience Factor – Loading

VEFD:Vessel Experience Factor – Disch

Postingan lain yang mungkin berhubungan:

• January 19, 2009 -- Penanganan Muatan Tanker
• July 16, 2010 -- Cara mendapat VCF (Volume Convertion Factor), membuka ASTM table 52
• July 16, 2010 -- Cara mendapat WCF (Weight Convertion Factor), membuka ASTM table 57
• July 16, 2010 -- Density reduction, ASTM table 53
• July 16, 2010 -- Cara mendapat VCF (Volume Corection Factor), membuka ASTM table 54
• November 5, 2009 -- Menentukan Transport Lost
• November 5, 2009 -- Perhitungan Muatan Minyak BB
• July 11, 2009 -- Minimum Under Keel Clearance
• January 24, 2009 -- MUATAN BERBAHAYA (DANGEROUS GOODS)
• February 15, 2010 -- Liquefied natural gas, LNG

On board, 05 November 2009

Tujuan dari menghitung transport lost adalah agar mualim satu bisa menjadikan faktor batasan toleransi jumlah muatan di pelabuhan Disch yang harus di bongkar agar tidak mengalami claim oleh pertamina pemilik muatan.

Tujuan dari menghitung transport lost adalah agar mualim satu bisa menjadikan faktor batasan toleransi jumlah muatan di pelabuhan Disch yang harus di bongkar agar tidak mengalami claim oleh pertamina atau pemilik muatan.

• CONTOH PERHITUNGAN

SHIP FIGURE AFTER LOADING

BL ( DLM BARRELS)

P = 3090.039

K = 4026.115

S = 4023.743

Discharging “ Bengkulu” (BEFORE DISCARGE) → 0.10 % →  0.08 %

Grade       SG     Temp.   Daft.53     Daft.54     Daft.57

Premium = 0.723 / 28° C → 0.7336 – 0.985244 – 0.7209

Kerosine = 0.793 / 31° C → 0.8043 – 0.985658 – 0.7905

Solar      = 0.824 / 31° C → 0.8348 – 0.986696 – 0.8205

• Take KEROSINE ( Transport Lost ) →  0.08 %

0.08  x BARELS A.L  → 0.08  x  4011.791  =  3.209 BRLS

100                                100

Berarti BARRELS before discharge harus =  → 4011.791 – 3.209 = 4008.582 BRLS

4008.582 : 6.293 = 636.990 ( NET KL.15° C )

636.990: 0.985658 = 646.258  ( KL.OBS )

KL OBS = 647.344 – 646.258 = 1.086 K/L (SAVE)

Waktu pembongkaran  0.30 %  →  0.28 %

0.28  x BARELS B.D  → 0.28  x  4008.582  =  11.224 BRLS

100                                100

BARELS → 4008.582 – 11.224    = 3997.358

3997.358 : 6.293       = 635.207 NET KL.15° C

635.207  : 0.985658   = 644.449 KL OBS

KL OBS = 646.258 – 644.449      = 1.809 K/L (SAVE)

Catatan:

Temp Turun – - Barrels naik — OBS Turun.

SG naik – ——- OBS naik – —- Barrels Turun.

• Take SOLAR ( Transport Lost ) →  0.08 %

0.08  x BARELS A.L  →  0.08  x  4008.896 =  3.207 BRLS

  100                            100

Berarti BARRELS before discharge harus =  → 4008.896 – 3.207 = 4005.689 BRLS

4005.689: 6.293 = 636.530 ( NET KL.15° C )

636.530 : 0.986696 = 645.112  ( KL.OBS )

KL OBS = 646.167 – 645.112 = 1.055 K/L (SAVE)

Waktu pembongkaran  0.30 %  →  0.28 %

0.28  x BARELS B.D  →  0.28  x  4005.689  =  11.216 BRLS

    100                               100

BARELS → 4005.689 – 11.216    = 3994.473

3994.473 : 6.293       = 634.748 NET KL.15° C

634.748   : 0.986696   = 643.306 KL OBS

KL OBS = 644.403 – 643.306      = 1.097 K/L (SAVE)

Sekian orek – orean saya semoga menjadi referensi perhitungan bagi calon Senior Officer, mualim II yang ingin belajar menjadi C/O.

Postingan lain yang mungkin berhubungan:

• July 16, 2010 -- Cara mendapat VCF (Volume Convertion Factor), membuka ASTM table 52
• July 16, 2010 -- Cara mendapat WCF (Weight Convertion Factor), membuka ASTM table 57
• July 16, 2010 -- Density reduction, ASTM table 53
• July 16, 2010 -- Cara mendapat VCF (Volume Corection Factor), membuka ASTM table 54
• November 5, 2009 -- Perhitungan Muatan Minyak BB
• December 15, 2009 -- Ukur dan Hitung Minyak
• January 24, 2009 -- MUATAN BERBAHAYA (DANGEROUS GOODS)
• January 19, 2009 -- Penanganan Muatan Tanker
• February 15, 2010 -- Liquefied natural gas, LNG
• February 3, 2010 -- Mualim II Emergencies and Cargo handling

On board, 05 November 2009

Berikut ini saya merangkum beberapa perhitungan Muatan untuk tanker charter pertamina:

Setelah selesai memuat/ loading perhatikan:

1. Draft

2. Sounding Tanki

3. Sample ( SG, dan Temperature)

Rumus:

KL.OBS  x  DAFT.54 = NET.KL 15°C

NET. KL15°C x DAFT.52 = BARELS 60`F

NET.KL15°C x DAFT.57 = L/T (Long Ton)

L/T x 1.01605            = MT (Metric Ton)

Atau untuk muatan dgn temperatere tinggi T.E.F di perhitungkan (Tank Expansion Factor)

OBS VOL           =

T.E.F                  =                              x

GKL                   =

VCF (table 54 )  =                              x

NET.KL 15°C      =

(table.52)          =                               x

BRLS                  =

NET.KL 15°C      =

WCF                  =                             x ( Density – 0.0011)

M/T                    =

atau     L/T x  1.01605   =  M/T

NET.KL 15°C      =

(TABLE.57)         =                            x

L/T                     =

Cargo density at 15°C based on table 53 (ASTM D1250)

Volume Correction Factor based on table 54 (ASTM D1250)

Net volume in Kilo Liter at 15°C.

Volume Convertion Factor based on table 52 (ASTM D1250)

Volume in Barrels at 60°F.

Weight Convertion Factor based on table 57 (ASTM D1250)

• DALAM PEMUATAN DI PELABUHAN LOADING Selisih muatan antara darat dengan kapal saat muat harus kurang dari 0.30 % ( Perbedaan ini di sebut R1)

Contoh:

Angka darat adalah: y

Angka Kapal adalah: x

satuan angka yang di gunakan pertamina adalah Barrels , jadi patokan Barrels

RUMUS :         x – y    x 100  …….  ( harus kurang dari 0.30 % )

                        BL

Apabila Lebih dari 0.30 % selisih nya (angka kapal kecil di banding angka darat) maka,

“ LETER OF PROTEST”  yaitu darat protes ke kapal

Contoh:

Sebuah Kapal Tanker Loading solar di TT. TG. Gerem Merak, Dengan Jumlah Muatan sbb:

Angka darat / BL ( Bill Of Lading ) = 16.590 BRLS,

Angka Kapal ( Ship Figure After Loading) = 16.450 BRLS,

Jawab:

Rumus 

x – y    x 100

      BL

(Angka darat) – (Angka Kapal)  x 100

( Bill Of Lading )

16.580 -  16.470  x 100      =     0.66% ( > 0.30%) lebih dr toleransi 0.30 %

            16.590

Protest yang di buat darat dengan kapal membalasnya dgn ditanda tangani oleh Master for received only ( hanya untuk di ketahui )

• DALAM PERJALANAN DARI AFTER LOADING (AL) SAMPAI BEFORE DISCHARGING (BD) → TRANSPORT LOST

Dari AL s/d BD selisih muatan harus kurang dari 0.10 % ( Perbedaan ini di sebut R2) ini adalah tanggung jawab kapal.

Rumus:

BD – AL    x   100 =  …….. ( hasil nya harus < 0.10 % )

         BL

• DALAM PEMBONGKORAN ( MULAI BONGKAR s/d SELESAI )

Rumus:

AR – BD  x  100 =  …….. ( hasil nya harus < 0.30 % )

          BL

AR = Actual Recieved ( Penerimaan Darat )

Kasus yang menjadi perhatian Operation Manager terhadap armada kapal tanker yang di charter oleh pertamina adalah pada pion R2, atau transport lost.

Postingan lain yang mungkin berhubungan:

• July 16, 2010 -- Cara mendapat VCF (Volume Convertion Factor), membuka ASTM table 52
• July 16, 2010 -- Cara mendapat WCF (Weight Convertion Factor), membuka ASTM table 57
• July 16, 2010 -- Density reduction, ASTM table 53
• July 16, 2010 -- Cara mendapat VCF (Volume Corection Factor), membuka ASTM table 54
• November 5, 2009 -- Menentukan Transport Lost
• December 15, 2009 -- Ukur dan Hitung Minyak
• January 19, 2009 -- Penanganan Muatan Tanker
• January 24, 2009 -- MUATAN BERBAHAYA (DANGEROUS GOODS)
• February 15, 2010 -- Liquefied natural gas, LNG
• February 3, 2010 -- Mualim II Emergencies and Cargo handling

On board, 21 August 2009

What is an Electronic chart display system?

An electronic chart display system is a general term for all electronic equipment that is capable of displaying a vessel’s position on a chart image on a screen.

There are two classes of electronic chart display systems. The first is an ECDIS (Electronic Chart Display and Information System), which can meet IMO/SOLAS chart carriage re­quirements. The second is an ECS (Electronic Chart System), which can be used to assist navigation, but does not meet IMO/SOLAS chart carriage requirements.

ECDIS

ECDIS equipment is specified in the IMO ECDIS Performance Standards as follows:

Electronic Chart Display and Information System (ECDIS) means a navigation information system which, with adequate back up arrangements, can be accepted as complying with the up-to-date chart required by regulation V/1 9 & V/27 of the 1974 SOLAS Convention.

Where the term ECDIS is used in this document, this is to be understood as those naviga­tional electronic chart systems, which have been tested, approved and certified as com­pliant with the IMO ECDIS Performance Standards and other relevant IMO Performance Standards and thus is compliant with SOLAS ECDIS requirements.

ECS

ECS is specified in ISO 19379 as follows:

ECS is a navigation information system that electronically displays vessel position and relevant nautical chart data and information from an ECS Database on a display screen, but does not meet all the IMO requirements for ECDIS and is not intended to satisfy the SOLAS Chapter V require­ments to carry a navigational chart.

ECS equipment ranges from simple hand held GPS enabled devices to sophisticated stand­alone computer equipment interfaced to ship systems.

Where are the rules for professional marine navigation written down?

The 1974 International Convention for the Safety of Life at Sea (SOLAS 1974), subse­quently amended in 2000 and 2002, specifies the requirements for the navigational equip­ment to be used onboard ships entitled to fly the flag of a party to the convention. This Convention was adopted by the International Maritime Organisation (IMO), the United Nations Organisation that is concerned with maritime transportation.

IMO member states are obliged to adopt IMO rules and regulations into their national leg­islation. However, only when the convention text has been incorporated into national leg­islation does it take effect for the individual ships registered in that country. This process of incorporation into national legislation may vary from a few months to several years.

The country in which a ship is registered and hence which flag it is flying is known as the Flag State. It is the national maritime administration representing the Flag State, which controls the adherence to the SOLAS carriage requirements (Flag State control).

The national maritime administration is also responsible for Port State control. Ships arriv­ing at a port may be subject to Port State control by local officials (Port State Control Of­ficers – PSCOs) based on Flag State regulations and international agreements. Port states

cooperate within regions to apply consistent standards, for example the European nations and Canada cooperate under the umbrella of the Paris Memorandum of Understanding (Paris MOU).

What are the IMO requirements for the carriage of nautical charts?

What is a nautical chart?

Nautical charts are special purpose maps specifically designed to meet the requirements of marine navigation, showing amongst other things depths, nature of bottom, elevations, configuration and characteristics of coast, dangers and aids to navigation.

Nautical charts offer a graphical representation of relevant information to mariners for executing safe navigation.

Nautical charts can be distributed in analogue form, as paper charts or digitally, and are available from a variety of sources, both governmental and private. For information on paper charts see the separate document “Facts about paper charts”

The requirements for carriage of nautical charts are laid down in SOLAS Chapter V. The relevant regulations are:

- Regulation 2, defines the nautical chart

- Regulation 19, specifies the equipment to be carried on different types of ships and

- Regulation 27, specifies the requirement to keep charts and publications up to date. IMO SOLAS V/2

2.2 Nautical chart or nautical publication is a special-purpose map or book, or a specially com‑

piled database from which such a map or book is derived, that is issued officially by or on

the authority of a Government, authorized Hydrographic Office or other relevant govern‑

ment institution and is designed to meet the requirements of marine navigation.

The nautical charts and nautical publications referred to in regulation V/2 are commonly referred to as “official charts and publications”

IMO SOLAS V/19

2.1 All ships irrespective of size shall have:

2.1.4 nautical charts and nautical publications to plan and display the ship’s route for the intend­ed voyage and to plot and monitor positions throughout the voyage; an Electronic Chart Display and Information System (ECDIS) may be accepted as meeting the chart carriage requirements of this subparagraph;

2.1.5 back-up arrangements to meet the functional requirements of subparagraph 2.1.4, if this
function is partly or fully fulfilled by electronic means; 1

IMO SOLAS V/27

Nautical charts and nautical publications, such as sailing directions, lists of lights, notices to mari­ners, tide tables and all other nautical publications necessary for the intended voyage, shall be adequate and up to date.

Most vessels still satisfy carriage requirements for charts and publications by the use of paper products, however amendments to SOLAS regulations that came into force in July 2002 allow these carriage requirements to be satisfied solely by electronic means so long as a suitable back up is provided.

The three regulations referred to above show that the carriage requirement for charts and publications can be fulfilled by:

- Carriage of official and up to date paper charts, or

- Carriage of a type-approved ECDIS (in accordance with the requirements of the IMO ECDIS Performance Standards – i.e. using up to date Electronic Navigational Charts (ENC) supplemented by an appropriate back up arrangement).

What kinds of electronic charts are available?

There are two types of electronic chart – raster and vector. A raster chart is a scanned and passive image of a paper chart, whereas a vector chart corresponds to a digital analysis by object (points, lines, areas etc.). See Section 4 for further technical details.

Picture 1: Object in the raster chart, example of raster chart (left) and example of vector chart with vessel’s symbol in the middle (right).

What are official charts?

Charts issued by or on the authority of a Government, authorized Hydrographic Office or other relevant government institutions are official and may be used to fulfil carriage re­quirements (provided they are kept up to date).

All other nautical charts are by definition not official and are often referred to as private charts. These charts are not accepted as the basis for navigation under the SOLAS con­vention.

There are two kinds of official digital charts commonly available; Electronic Navigational Charts (ENC) and Raster Navigational Charts (RNC).

What is an ENC?

ENC stands for “Electronic Navigational Chart”. The term was originally introduced for dig­ital chart data complying with the IHO chart data transfer standard S-57. By IMO definition ENCs can only be produced by or on the authority of a government, authorised Hydro-graphic Office or other relevant government institution. Any other vector data is unofficial and does not meet carriage requirements.

ENCs have the following attributes:

- ENC content is based on source data or official charts of the responsible Hydrographic Office;

- ENCs are compiled and coded according to international standards;

- ENCs are referred to World Geodetic System 1984 Datum (WGS84);

- ENC content is the responsibility and liability of the issuing Hydrographic Office;

- ENCs are issued only by the responsible Hydrographic Office; and

- ENCs are regularly updated with official update information distributed digitally.

See section “Meeting carriage requirements for ECDIS” below and Section 4 for further details.

Picture 2: ENC data displayed on a type approved ECDIS.

How do I recognise an ENC?

When I am buying

Only authorized distributors sell ENCs in ENC services which include the delivery of update information. The distributors are authorized either directly by the originating Hydrographic Office or by a cooperation of Hydrographic Offices.

When used in an ECDIS

ECDIS distinguishes an ENC from unofficial data. When unofficial data is used, ECDIS in­forms mariners that they must navigate by means of an official, up to date, paper chart by a continuous warning on the screen.

If unofficial data is shown on the ECDIS display, its boundary is to be identified by a special line style. This boundary is visualized as a “one-sided” RED line with the diagonal stroke on the unofficial side of the line.

Further the mariner can use an ECDIS function to interrogate the chart display to obtain the chart details like information on originator, edition number and status of updating.

How are ENCs distributed?

The International Hydrographic Organisation (IHO) provides an interactive web catalogue (www.iho.int) displaying the status of worldwide ENC production. This system has point­ers for guiding users to ENC suppliers and distributors. A three-colour scheme is used to distinguish between degrees of accessibility.

This catalogue shows that many common shipping routes are already covered by ENCs.

The illustration below shows the front page of the catalogue, which can be found at the IHO web-site at www.iho.int, look under “ENC”.

Some HOs (eg Canada and Australia) make their RNCs and ENCs available to users via their own distributor networks; these distributors often offer additional folio services to shipping companies.

Picture 4: IHO Global ENC Catalogue, March 2007.

How are ENCs protected?

A majority of all ENCs are only made available to the end-users in a protected form com­pliant with the IHO S-63 Data Protection scheme. The standard maintains the integrity in all transactions between the service provider and the end-user. The protection scheme enables the end user systems to check the authenticity of the supplied information.

The S-63 protection scheme defines a mechanism for encrypting ENC information and ap­plying a digital signature to enable authentication of the chart data by the end-user. The end-user will require a decryption key to access and view the ENC data protected by the scheme. Each ENC chart is encrypted with a different key, and the decryption keys are is­sued to specific end-user systems and can consequently not be exchanged or shared by different systems. The required decryption keys are distributed to the end-users as ‘Cell Permits’ by the service provider.

The operation of a protection scheme should not add any operational overhead for the end-users since all aspects of ENC decryption and authentication are handled automati­cally by the chart system. The end-user will occasionally receive new Cell Permits from their service provider when their ENC subscription is renewed or there are changes to the ENC chart outfit. The updated Cell Permits must be imported into the chart system to en­able it to automatically process new ENC deliveries and updates.

A majority of all ECDIS and ECS suppliers have developed support for IHO S-63 and can read protected ENCs.

A few nations distribute their ENCs without using encryption; all ECDIS systems are able to access and display these ENCs.

Are there other ways that ENCs can be distributed?

The International Hydrographic Organisation has approved the distribution of ENCs in the internal format used by the individual ECDIS manufacturer. The generic name of this for­mat is SENC – System-ENC. Depending on the make of ECDIS this can increase the speed of loading of ENC-data. The IHO requires service providers using this method of SENC-dis­tribution to gain the agreement of the Hydrographic Offices supplying the ENCs and to use type approved software to ensure that the integrity of the SENC data is maintained.

What is an RNC?

RNC means “Raster Navigational Chart”. RNCs are digital raster copies of official paper charts conforming to IHO Product Specifications RNC (S-61). By definition RNCs can only be issued by, or on the authority of, a national Hydrographic Office.

RNCs have the following attributes:

- RNCs are a facsimile of official paper charts;

- RNCs are produced according to international standards;

- RNC content is the responsibility of the issuing Hydrographic Office; and

- RNCs are regularly updated with official update information distributed digitally.

The IMO performance standards for ECDIS states that where ENCs are not available, RNCs may be used in ECDIS to meet carriage requirements. However, when the ECDIS is us­ing RNCs it should be used together with an appropriate folio of up to date paper charts. See section “Meeting carriage requirements for ECDIS” below and Section 2 for further details.

Because of their nature, RNCs when used in ECDIS do not provide the same level of func­tionality that is provided by ENCs; the limitations of operating with RNCs are outlined in IMO SN Circulars 207 and 255 (see Annex to this section).

How are ENCs and RNCs kept up to date?

In order to meet carriage requirements, official charts must be kept corrected by Notices to Mariners issued by Hydrographic Offices.

ENCs and RNCs are kept up to date by applying regular, for example weekly, update in­formation to the chart data via a data file. The update file may be transferred by wireless transmission, or by a suitable media e.g. CD. The actual updating is applied automatically by the ECDIS to its chart database. Another standard function of ECDIS is the capability of updating the ENC manually which may be used if the digital update is not available.

At present most ENC and RNC updates are supplied to ships on CD but ‘remote updating’ using satellite (or, when in port, shore based) telecommunications is becoming more and more common. A number of ENC service providers already have updating services using e-mail and web and other means; details may be obtained from ENC distributors.

Is it possible to check that all updates have been applied to the ENC?

Updates to ENCs are sequential, and the sequence is unique to each ENC. During the up­dating process ECDIS always checks that all updates in the sequence have been applied. If an update is missing then the ECDIS will indicate this; it is not possible to load later updates until the missing update is applied.

The ECDIS maintains a list of updates applied and the date of application. This list can be used to check the update status of the ENCs loaded. Should all available ENCs show the same date for the latest update, it is likely that they have not been updated regularly, and the distributor should be contacted for verification. Furthermore it is possible to use tradi­tional sources of information, such as Notices to Mariners, to verify updates.

Port State Control officers may use the ECDIS listing to ensure that ENCs are being kept up to date in accordance with SOLAS V Regulation 27.

What is ECDIS?

ECDIS equipment is specified in the IMO ECDIS Performance Standards (IMO Resolution A.817 (19)) as follows:

Electronic Chart Display and Information System (ECDIS) means a navigation information system which, with adequate back up arrangements, can be accepted as complying with the up-to-date chart required by regulation V/19 & V/27 of the 1974 SOLAS Convention, by displaying selected information from a system electronic navigational chart (SENC) with positional information from navigation sensors to assist the mariner in route planning and route monitoring, and by displaying additional navigation-related information if required.

ECDIS is a ship borne navigational device and as such it is the responsibility of IMO. It must support the whole range of navigational functions that make use of the characteris­tics of the chart data and their specific presentation. Moreover, to be an ECDIS the equip­ment must be shown to meet all the requirements of the IMO Performance Standards (IMO Resolution A.817(19)) and offer, besides the graphic presentation of chart data, additional information about the characteristics of the displayed features.

Within the ECDIS, the ENC database stores the chart information in the form of geographic objects represented by point, line and area shapes, carrying individual attributes, which make any of these objects unique. Appropriate mechanisms are built into the system to query the data, and then to use the obtained information to perform certain navigational functions (e.g. the anti-grounding surveillance).

The presentation of the current position, range/bearing functions and route planning ca­pabilities are other examples of the minimum ECDIS requirements laid down in the IMO Performance Standards for ECDIS.

The presentation of ENCs on the screen is specified in another IHO standard, the “Colours and Symbols Specifications for ECDIS IHO S-52”, i.e. in its Appendix 2, called ”ECDIS Presentation Library”. This style of presentation is mandatory.

The use of ENCs in a tested, approved and certified ECDIS and with appropriate back up arrangements, is the only paperless chart option for vessel navigation.

How is an ECDIS approved and by whom?

To ensure that ECDIS equipment intended for onboard use is seaworthy, it must pass type approval and test procedures developed by the International Electrotechnical Commission (IEC) based on the ECDIS Performance Standards of IMO and applying the IHO require­ments, S-52 and S-57 in particular.

Type approval is a method to show conformance with IMO requirements on a legal basis – it is initiated and required by all Flag States which are Member States of the European Union and by many others outside including United States, Japan and Australia. ECDIS type approval is the certifications process that ECDIS equipment must undergo before it will be considered to comply with the IMO Performance Standards for ECDIS by the inter­national shipping community.

Type approval is normally conducted by recognized organisations or by marine classifica­tion societies nominated by Flag States. Some maritime nations also have type approval programs within their maritime safety administration or Department of Marine Transporta­tion. European Governments have agreed about mutual recognition of their ECDIS type approval certificates – indicated by the so-called “Wheel Mark” sign showing conformity with the Maritime Equipment Directive of the European Union.

Meeting Carriage Requirements with ECDIS

Only a type approved ECDIS operating with up to date ENCs and with appropriate back up may be used to replace all paper charts on a vessel. Where ENCs are not yet available, IMO regulations allow Flag States to authorise the use of RNCs (together with an appropri­ate folio of paper charts) – see below. Note that in all other cases the vessel must carry all paper charts necessary for its intended voyage.

From the regulatory perspective, the most important statement about the legal status of ECDIS is contained in the amended Chapter V of the SOLAS Convention set into force on 1 July 2002. As stated earlier in this section, ECDIS is specifically referred to in Regulation 19 ”Carriage requirements for ship borne navigational systems and equipment”.

However, in order to replace paper charts, such systems must fulfil considerable technical requirements laid down in ECDIS Performance Standards:

- The chart data in use must be official – ENCs where these are available;

- The graphic display on the screen must meet the equipment-independent specifica­tion; and

- The equipment must support the full range of navigational functions that can be per­formed on the traditional paper charts.

Back up requirements

No electronic system is completely failsafe. IMO Performance Standards therefore require that the “overall system” include both a primary ECDIS and an adequate independent back up arrangement that provides:

- Independent facilities enabling a safe take over of the ECDIS functions in order to ensure that a system failure does not result in a critical situation; and

- A means to provide for safe navigation for the remaining part of the voyage in case of ECDIS failure.

However, these rather basic statements allow considerable leeway and there are various interpretations as to what are the minimum functional requirements, or what constitute ”adequate” back up arrangements.

There are two commonly accepted options:

- A second ECDIS, connected to an independent power supply and a separate GPS po­sition input;

- An appropriate up to date folio of official paper charts for the intended voyage

Some Flag States may permit other options (e.g. radar-based systems such as ”Chart-Radar”). Ship owners should consult their national maritime administration for specific advice.

At the request of IMO the IHO is currently seeking information from their member states on which paper charts covering their territorial waters would be appropriate to serve as a back up to ECDIS. IHO will compile this information and present it on its web site in the form of a catalogue.

Information on different maritime administrations’ accepted back up arrangements can be found in Section 2.

What to do in areas without ENC coverage?

In 1998 the IMO recognised that it would take some years to complete the world’s cover­age of ENCs. As a consequence IMO ECDIS Performance Standards were amended add­ing a new optional mode of operation of ECDIS, the Raster Chart Display System (RCDS) mode. In this mode RNCs can be used in ECDIS to meet SOLAS carriage requirements for nautical charts. However, this is only allowed if approved by the Flag State. The intention of those changes was to allow the ECDIS to operate as far as possible on official chart data; ENCs where they were available and RNCs to fill in the gaps.

IMO took note of the limitations of RNCs as compared to ENCs (see IMO SN Circular 207 at Annex), and the revised ECDIS Performance Standards require that the ECDIS must be used together with “an appropriate folio of up to date paper charts” for the areas where RCDS mode is employed. The intention was to allow the number of paper charts carried by a vessel to be reduced where RCDS mode was employed, but only to a level compat­ible with safe navigation. No definition of an “appropriate folio” was provided by IMO and consequently different Flag States developed individual interpretations.

As there is no common interpretation of the term “appropriate” ship owners should consult their Flag State as to whether RCDS mode is allowed and under what conditions.

A web-based catalogue showing world coverage of all ENCs, RNCs and paper charts avail­able is currently under preparation by the IHO.

In areas where ENCs or RNCs are not available vessels must carry all paper charts neces­sary for the intended voyage.

Section 2 gives details of the implementation by specific maritime administrations.

Does your ECDIS system Meet Carriage Requirements?

Are ENCs available for area of operation?	YES	NO	YES	NO
What Digital Charts are being used in the ECDIS by the mariner?	ENC (coverage at an appropriate scale for navigation)	RNC (coverage at an appropriate scale for navigation)	RNC	Private charts (6)
What back up system is required?	Independent ECDIS or other back up solution required	Independent ECDIS or other back up solution required	None required (3)	None required (3)
What are the requirements for the carriage of Official paper charts?	None needed (1) (except if back up is a folio of paper charts)	An “appropriate” folio of up to date paper charts to be used in conjunction with the ECDIS in RCDS mode	All up to date paper charts required for safe navigation in areas where ENCs are available	All up to date paper charts required for safe navigation for the intended voyage
How is the ECDIS operating ? Does the ECDIS fulfil Chart Carriage Requirements?	As an ECDIS YES (1)	As an ECDIS in RCDS mode YES (2)	As an ECDIS in RCDS mode NO (4)	As an ECS NO (5)

Table 1: ECDIS Carriage Requirements – a summary

Notes to table above:

- (1) Some Flag States may require specific documentation to allow this.

- (2) Requires approval of vessel’s Flag State – Flag State defines meaning of ‘appropri­ate’

- (3) Back up system is only required if ECDIS is intended to meet carriage require­ments

- (4) For ECDIS to fulfil Carriage requirements vessels must use ENCs where these are available

- (5) Paper charts (not the ECDIS) must remain the primary means of navigation

- (6) If private charts are used in an ECDIS the system is regarded as operating as an ECS. ECDIS operating as ECS, ECS systems meeting RTCM standards or Private charts meeting ISO standards being used in ECDIS do not meet carriage require­ments.

Can chart format names indicate carriage compliance?

There has been much confusion with regard to the names used to describe electronic chart distribution formats; the diagram below is designed to clarify the situation. From the dia­gram it can be seen that the same distribution format can be used for the delivery of both private and official chart data. For instance ’BSB’ is the term used for the distribution for­mat of US and Canadian RNCs; the same term is used for the distribution of private raster chart data in other areas (for example in European waters). There can also be confusion with ENCs; private vector chart data delivered in S-57 format does not meet IMO require­ments and should never be named as ENC. Similarly private vector data delivered in SENC format can be mistaken for ENCs delivered in the same SENC format.

Therefore the most important factor to consider is the source of the electronic chart data; this determines its status and the purpose for which it may be used. However, only the combination between the status of the chart data and the functionality of the particular device finally decides if its practical operation can be stated as ECDIS-mode or as ECS­mode.

Picture 5: Examples of Electronic Chart Formats. Many ECS systems are able to use ENC or RNC data, how­ever even when using official charts they may not be used to fulfil carriage requirements.

Acceptance of ECDIS by Port State control

Ships arriving at a port may be subject to Port State control by local officials based on Flag State regulations and international agreements. Nations have formed a number of regional groups to ensure consistent application of Port State controls.

In Europe the Port State control acts on the regulations set out in the Paris Memorandum of Understanding. Its ECDIS guidelines explain how a PSCO should assess whether a ship is using electronic charts in accordance with SOLAS requirements. Checks may include whether:

- The ship has documentation indicating that the system complies with IMO Perform­ance Standards for ECDIS. In the absence of such documentation, the PSCO should seek confirmation from the Flag State that the system does meet the statutory re-q u i rem ents;

- The system is being used for primary navigation. It should be established if ECDIS is used in the ENC mode or RCDS mode or in both modes;

- There are written procedures onboard the vessel for using ECDIS;

- The master and watch-keeping officers are able to produce appropriate documenta­tion that generic and type-specific ECDIS familiarisation has been undertaken;

- The charts used for the intended voyage are the latest official editions;

- The charts in use are updated; and

- There are approved back up arrangements available to ensure a safe transfer of the ECDIS functions in the event of ECDIS failure and to provide safe navigation for the remaining part of the voyage.

Is there a need for ECDIS training?

Unlike the paper chart, ECDIS is a highly sophisticated system which, besides the naviga­tional functions, includes components of a complex, computer-based information system. In total, the system includes hardware, operating system, ECDIS software (kernel and user interface), sensor input interfacing, electronic chart data, rules for presentation and display, status and parameters of alarms and indications, etc. All these items are accessed through an appropriate human-machine interface. As such, care must be taken when navi­gating with ECDIS to avoid

- False operation

- Misinterpretation

- Malfunction or, even worse,

- Over-reliance on this highly-automated navigation system

As with any type of shipboard navigation equipment, it can only be as good as those who use it and what it is being used for. In the case of ECDIS and electronic charts, if the mari­ner is well trained then the system provides the information flow that the mariner needs to make good decisions and therefore contributes significantly to safe and efficient naviga­tion. Stated another way, an electronic chart system is another tool to enable mariners to perform their job better. However, just having some “knowledge” about “functions” and “operational controls” is insufficient to maximise the benefits of ECDIS; proper training is absolutely necessary.

What are the requirements for ECDIS training?

ECDIS and other electronic charting systems have become increasingly important to ship navigation and are already widely used either as a primary navigation tool or as an aid to navigation. The systems are increasingly complex, and require adequate and appropriate training in order to be operated correctly and safely. Without proper training, these sys­tems will not be used to their full potential and could under some circumstances increase the hazard to navigation. The STCW (Standards of Training, Certification and Watch-keep­ing) and ISM (International Safety Management) codes put the responsibility firmly on the shipowner to ensure that mariners on their vessels are competent to carry out the duties they are expected to perform. If a ship is fitted with ECDIS, the shipowner has a duty to ensure that users of such a system are properly trained in the operation and use of elec­tronic charts and are familiar with the shipboard equipment before using it operationally at sea.

There is no specific regulation or reference to ECDIS systems in the STCW Convention. However, since ECDIS systems are related to electronic charts, references about them are considered to be included in the material covered by the word “chart”:

- To encourage effective ECDIS education, the IMO approved a standardised model course for ECDIS training on the operational use of ECDIS in 1999 (IMO course 1.27). This course is offered by approved training institutions and maritime academies. Maritime administrations can provide information on approved institutions. Some Flag States have developed their own training courses in ECDIS in order to be able to recognise the training certificates.

- Type specific ECDIS training is provided by equipment manufacturers. Further details on ECDIS training are to be found in Section 3. What are the operational considerations when using ECDIS?

Navigating with ECDIS is fundamentally different from navigating with paper charts. Im­portant bridge work-processes are significantly affected, in particular, voyage planning and voyage execution task. These require careful analysis and consideration:

Voyage Planning

ECDIS provides a number of additional planning functions and features such as safety contours, alarms, click-and-drop facilities for waypoints and markers, etc. Whilst in many ways ECDIS makes voyage planning easier it is still possible to make errors, however these are likely to be of a different type to those encountered when using paper charts.

Even though ENC coverage is increasing rapidly, many vessels will, to some degree, have to operate a dual – or even triple – system with ENCs paper and raster charts. Planning and validation of the route has therefore to consider issues such as which chart types are available for the various segments of the voyage. The format of the voyage plan is likely to differ from the traditional alphanumeric lists of waypoints used with paper charts and should include information on the usability of connected electronic navigational devices such as GPS and AIS and their actual alarm settings.

It is essential to make use of the in-built automatic check functions provided by ECDIS when validating and approving the voyage plan. Thought also needs to be given to ensur­ing that a backup to the voyage plan on the ECDIS is available in case of equipment failure of the ECDIS itself or the connected sensors.

It is important that there is good communication of the voyage plan to all bridge officers so that they are prepared for the intended voyage. This should include information on equipment status and backup procedures

Voyage execution

At the beginning of the voyage, as well as at any change of watch, the officers should re­view the voyage plan and agree the selected pre-settings of functions, alarms and indica­tors to be used on the ECDIS.

Where vessels carry paper charts as well as an ECDIS the role of the ECDIS and the charts should be considered. If the ECDIS is used for real time navigation, the statutory require­ments regarding monitoring of the progress of the voyage and marking of positions will need to be considered:

· are positions marked in paper charts solely for record keeping purposes?

· what steps are taken to ensure that intended tracks marked on the paper charts cor­respond with the ECDIS information?

· have the bridge procedures set in place by the shipping company been adapted for the use of ECDIS and are all persons concerned with the navigation familiar with these adaptations

Over reliance on ECDIS

There is a tendency to put too much trust in computer based systems and believe what­ever is on the display. It is essential that officers remember to cross check the information displayed by all other means available; especially by looking out the window and watching the radar! Bridge-procedures must be adapted appropriately and ENC training must be carried out to alleviate these concerns.

Is there a mandatory requirement to carry ECDIS?

- In December 2006 the Marine Safety Committee (MSC) of IMO agreed amendments to the High Speed Craft (HSC) regulations requiring all HSC craft built after 2008 to be fitted with ECDIS and existing HSC to be retrofitted by 2010.

- At the same meeting MSC also accepted the findings of a Formal Safety Assessment (FSA) on ECDIS presented by Norway and other nations showing the positive benefit of fitting ECDIS. As a result of this study MSC has instructed the NAV sub-committee to discuss the extension of mandatory carriage of ECDIS to other classes of vessel and to report back to them in 2008.

What is ECS?

All systems, which are not tested to show compliance with the ECDIS Performance Stand­ards, can be generically designated as ”Electronic Chart Systems” (ECS). An ECS may be able to use either ENCs, RNCs or other chart data produced privately and could have functionality similar to ECDIS.

Some ECS equipment manufacturers also produce vector and raster data to use in their products. These suppliers have been producing private chart data for a number of years and have established themselves in the market. They were the pioneers and have estab­lished the idea and the use of electronic chart systems on vessels. Their charts are derived from Hydrographic Office paper charts or Hydrographic Office digital data.

Hydrographic Offices do not take any responsibility for the accuracy or reliability of pri­vately produced charts.

Where the vessel operates with ECS, the paper chart remains the official basis for naviga­tion onboard. The vessel must retain and use a full folio of up to date paper charts on­board, regardless of the type of electronic charts used.

Because ECS is not intended to meet SOLAS requirements, there are no IMO Performance Standards for ECS.

Some ECS manufacturers also use the term RCDS to describe their systems. In this case the manufacturer is stating that the system uses RNCs and possibly that it has the same functionality as required by the ECDIS Performance Standards. However, such systems cannot be used to meet carriage requirements.

The STCW and ISM codes put the responsibility firmly on the shipowner to ensure that mariners on their vessels are competent to carry out the duties they are expected to per­form. If a ship has ECS fitted, the shipowner has a duty to ensure that users of such a system are properly trained in the operation and use of electronic charts, are aware of the limitations compared to ECDIS and are familiar with the shipboard equipment before using it operationally at sea.

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On Friday, 31 July 2009

History

The IMO states that “The International Ship and Port Facility Security Code (ISPS Code) is a comprehensive set of measures to enhance the security of ships and port facilities, developed in response to the perceived threats to ships and port facilities in the wake of the 9/11 attacks in the United States” (IMO)

Development and implementation were speeded up drastically in reaction to the September 11, 2001 attacks and the bombing of the French oil tanker Limburg. The U.S. Coast Guard, as the lead agency in the United States delegation to the International Maritime Organization (IMO), advocated for the measure. The Code was agreed at a meeting of the 108 signatories to the SOLAS convention in London in December 2002. The measures agreed under the Code were brought into force on July 1, 2004

Scope

The Code is a two-part document describing minimum requirements for security of ships and ports. Part A provides mandatory requirements. Part B provides guidance for implementation.

The ISPS Code applies to ships on international voyages (including passenger ships, cargo ships of 500 GT and upwards, and mobile offshore drilling units) and the port facilities serving such ships.

The main objectives of the ISPS Code are:

To detect security threats and implement security measures

To establish roles and responsibilities concerning maritime security for governments, local administrations, ship and port industries at the national and international level

To collate and promulgate security-related information

To provide a methodology for security assessments so as to have in place plans and procedures to react to changing security levels

Requirements

The Code does not specify specific measures that each port and ship must take to ensure the safety of the facility against terrorism because of the many different types and sizes of these facilities. Instead it outlines “a standardized, consistent framework for evaluating risk, enabling governments to offset changes in threat with changes in vulnerability for ships and port facilities.”

For ships the framework includes requirements for:

Ship security plans.

Ship security officers

Company security officers

Certain onboard equipment

For port facilities, the requirements include:

Port facility security plans

Port facility security officers

Certain security equipment

In addition the requirements for ships and for port facilities include:

Monitoring and controlling access

Monitoring the activities of people and cargo

Ensuring security communications are readily available

Keamanan Tingkat 1 (Security Level 1)

tingkatan di mana tindakan pencegahan keamanan minimum yang harus dilaksanakan secara terus menerus.

1.Pengecekan identitas semua orang yang naik ke kapal dan mengkonfirmasikan tujuan mereka : karcis, pas naik kapal, dll;

2. Kapal berkoordinasi dengan fasilitas pelabuhan: menetapkan danmenjaga daerah aman,di wilayah tersebut dapat dilaksanakan kegiatan pengawasan terhadap orang-orang, bagasi(termasuk benda­-benda yang dibawa), barang-barang -pribadi, kendaraan dan isinya.

3.Kapal berkoordinasi dengan fasilitas pelabuhan untuk pemeriksaan terhadap kendaraan yang akan dimuat (car carrier, ro-ro);

Keamanan Tingkat 2 (Security Level 2)

Tingkatan di mana tindakan tambahan dari tingkatan keamanan minimum harus dilaksanakan pada waktu tertentu sebagai resiko meningkatnya suatu insiden keamanan.

Pada Keamanan Tingkat 2, Rencana Keamanan Kapal meliputi antara lain :

1.Personil tambahan:ronda keliling saat keadaan sepi untuk mencegahakses olehorang yang tidak berkepentingan;

2. Pembatasan jumlah akses ke kapal, mengidentifikasi akses yang harus ditutup dan peralatan yang memadai untuk pengamanannya;

3. Pencegahan akses pada lambung sisi laut, termasuk patroli perahu;

4. Menetapkan area terbatas pada sisi darat kapal, bekerjasama dengan fasilitas pelabuhan;

5. Meningkatkan frekuensipenggeledahan orang, barang pribadi, dan kendaraan yang naik atau dimuat ke kapal;

6.Melakukan pengawalan terhadap pengunjung kapal;

7. Mengadakan tambahan pengarahan bagi semua awak kapal tentang ancaman-ancaman yang sudah teridentifikasi, menekankan kembali prosedur pelaporan, orang, benda, atau kegiatan yang mencurigakan dan menekankan perlunya peningkatan kewaspadaan;

8.Mengadakan pemeriksaanmenyeluruh atau sebagian di kapal.

Keamanan Tingkat 3 (Security Level 3)

Tindakan pencegahan keamanan yang lebih khusus yang dilaksanakan ketika suatu insiden keamanan segera terjadi

Pada Keamanan Tingkat 3, Rencana Keamanan Kapal harus rinci mengenai tindakan yang dapat dilakukan oleh kapal, bekerja sama secara intensif dengan fihak-fihak yang terkait dan dengan fasilitas pelabuhan, meliputi:

1.Mengurangiakses menjadi hanya satu akses yang terkendali;

2. Hanya memberikan akses kepada fihak-fihak yang sedang menangani insiden keamanan dan ancama insiden keamanan ;

3.Mengarahkan orang-orang di kapal;

4.Penundaan kegiatan naik turun penumpang;

5.Penundaan kegiatan bongkar-muat barang dan pengiriman barang;

6.Pemindahan kapal;

7.Menyiapkan penggeledahan menyeluruh atau sebagian terhadap kapal.

Security Assessment

-Bagian yang penting dan integral dari proses pembuatan

-Perwira Keamanan Perusahaan (Company Security Officer)

-Dilaksanakan oleh orang-orang yang memiliki keterampilan memadai

1. Identifikasi tatacara, prosedur dan operasional keamanan yang sudah ada;

2. Identifikasi dan evaluasi kegiatandi atas kapal yang penting untuk dilindungi;

3. Identifikasi ancaman yang mungkin timbul terhadap kegiatan di atas kapal dan kemungkinan terjadinya ancaman;

4. Identifikasi kelemahan, mencakup faktor manusia di dalam infrastruktur, kebijakan dan prosedur.

Ship Security Plan (SSP)

Masing-masing kapal harus mempunyaiSSP yang disetujui oleh Administrasi

Suatu organisasi keamanan yang diakui(recognized security organization / RSO)boleh menyiapkan dokumen SSP

Suatu Rencana Keamanan Kapal (SSP) meliputi, hal-hal berikut :

1. Tindakan yang direncanakan untuk mencegah senjata, barang berbahaya yang dimaksudkan untuk digunakan terhadap orang – orang, kapal atau pelabuhan;

2. Identifikasi area terbatas dan tindakan untuk pencegahan akses bagi yang tidak berkepentingan masuk ke area tersebut;

3. Tindakan untuk pencegahan akses bagi yang tidak berkepentingan ke kapal;

4. Prosedur untuk merespon ancaman keamanan atau pel

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I. Kata Pengantar dan Pengenalan Umum

Diatas kapal, banyak alat/pesawat yang sehari-hari kita menggunakan, mengoperasikan dan tentu sudah kita kenal (kenal belum tentu tau) tapi apabila hendak menyebutkan dan menulisnya kita kesulitan seperti dalam menyebutkan bagian suatu alat/pesawat atau type tertentu. Sekedar mengenal saja tapi untuk menjelaskan nya,, wah nanti cari buku dulu . Apalagi hendak membuat requisition. pantasen kerja sama orang asing blm siap, alias hao-hao. hahaha… banyak nanya, kalo banyak nanya di atas kapal malu di katain goblok, kadang ada juga!?!.., jadi nanya aja sama mba google.. ketemu deh cerita seorang pelaut. . ….kata sambutan. OK kita kembali ke Laptop.

Valve atau biasa juga disebut dengan kerangan,

sangat berperan penting dalam sistim pipa kapal tanker, cargo pump dll guna menjaga kestabilan proses operasional, valve bertugas mengatur aliran (fluida) dalam suatu proses pembongkaran dan pemuatan cargo. Secara tidak langsung, maka valve dapat diandalkan untuk mengatur besar kecil nya flow, rendah tingginya level, rendah tingginya temperatur ataupun tekanan

Ketika valve telah dipasang dalam suatu rangkaian pipa. Pada saat valve di buka, fluida mulai mengalir, dan ketika valve ditutup maka fluida pun berhenti mengalir. Valve seperti ini bertugas untuk menutup penuh (fully closed) ataupun membuka penuh (fully opened) suatu aliran. Karena tugasnya hanya untuk membuka atau menutup maka valve sejenis ini dinamakan dengan ON/OFF valves atau Isolation valve.

Selain untuk membuka dan menutup atau fully opened dan fully closed, ada juga valve yang berfungsi untuk mengatur (regulate) aliran (fluida). Valve sejenis ini sering disebut sebagai Throttling valve.

Ada juga valve yang tugas nya mengatur agar aliran berjalan ke satu arah saja ataupun agar tidak terjadi reversed flow atau backflow. valve seperti ini disebut check valve atau one way valve.

Beberapa valve ada juga yang dirancang untuk melepaskan (release) kelebihan pressure untuk menjaga keamanan alat ataupun operator. Valve yang berfungsi untuk melepaskan kelebihan pressure ini sering disebut sebagai pressure relieve valve ataupun pressure safety valve (kedua jenis valve ini mempunyai fungsi yang sama tetapi prinsip kerjanya berbeda).

Valve secara umum dibagi menjadi 4 bagian, yaitu:

1.Opened/Closed valve
2. Throttling valve
3. Check valve
4. Pressure Relieve valve/Pressure safety valve

II. Bagian – Bagian Utama Valve

Sekarang ini telah bermacam-macam valve yang telah diproduksi oleh vendor. Namun pada dasarnya, valve-valve tersebut mempunyai bagian-bagian dasar yang sama. Seperti terlihat pada gambar dibawah ini. Bagian-bagian utama valve adalah; body, seat, disc, bonnet, gland, packing, stem dan handwell.

Seat dan Disc

Seat adalah bagian pada valve yang mantap/diam. Disc adalah bagian yang bergerak, bertugas sebagai pengontrol aliran. Disc akan bergerak keatas sehingga memberikan ruang lebih banyak agar fluida dapat mengalir, bergerak kebawah jika akan menutup dan menekan seat dengan rapat. Banyak valve yang berbeda namanya karena perbedaan disc dan seat ini. Seperti Ball Valve, Plug Valve, Needle Valve. (Akan dibahas kemudian).

Stem dan Handwell

Jika kita telusuri bagian valve dari bawah keatas setelah seat, disc lalu stem dan handwell yang semuanya tergabung jadi satu. Stem berbentuk batang yang sebagian berulir sebagian tidak. Handwell digunakan oleh operator untuk memutar stem, sehingga dapat menggerakkan disc keatas dan kebawah. Khusus saat pengoperasian Handwell, jika diputar searah jarum jam maka valve akan menutup, sebaliknya jika diputar berlawanan jarum jam maka valve akan membuka. Namun, ketika hendak menutup valve, hendaknya jangan memaksa putaran handwell terlalu keras dan kencang, karena akan menyebabkan kerusakan pada disc dan seat hingga masa pakai valve menjadi lebih cepat.

Bonnet dan Packing

Bonnet memberikan ruangan bagi disc untuk bergerak keatas saat valve dalam posisi membuka. Sedangkan packing, berfungsi sebagai material isolasi agar tak ada kebocoran fluida melalui stem.

Gland dan Gland Nut

Berfungsi untuk mengencangkan posisi packing terhadap stem. Jika ada kebocoran fluida melalui bagian ini maka dapat diantisipasi dengan mengencangkan Gland Nut. Jika tidak bisa juga, maka valve kemungkinan besar harus diganti.

III. Macam-macam valve yang sering ditemui di atas kapal maupun di tankers terminals (bukan terminal priok ) adalah sebagai berikut:

1. Gate valve
2. Globe valve
3. Angle valve
4. Needle valve
5. Plug valve
6. Ball valve
7. Butterfly valve
8. Diahpgram valve
9. Pinch valve
10. Check valve
11. Relieve valve
12. Safety valve

Penjelasan masing-masing Valve tsbt sbb:

1. Gate valve

Gambar Gate valve

Nama “Gate valve” diambil karena bentuk disc dari jenis valve ini pada saat menutup atau membuka berlaku seperti “Gate” (Gate dari bahasa inggris = Gerbang/Pagar). Dimana saat disc membuka keatas maka seluruh aliran akan bebas masuk tanpa hambatan yang berarti, namun pada saat disc tertutup rapat maka aliran akan berhenti tertahan oleh disc tersebut.

Gate valve mempunyai body dan stem yang panjang. Kegunaan dari jenis valve ini adalah hanya untuk menutup dan membuka aliran (fully closed & fully opened position), on/off control dan isolation equipment.

Gate valve tidak bisa digunakan untuk mengatur besar kecilnya aliran (regulate atau trotthling). Karena akan merusak posisi disc nya dan mengakibatkan valve bisa passing pada saat valve ditutup (passing = aliran tetap akan lewat, walaupun valve sudah menutup), disc tidak menekan seat dengan baik yang diakibatkan karena posisi disc sudah berubah (tidak rata lagi).

Pada saat Gate valve terbuka sebagian (misal 50% opening), maka aliran fluida akan sebagian lewat dibawah disc yang menyebabkan turbulensi (turbulensi = aliran fluida yang bergejolak) pada aliran tersebut, turbulensi ini akan menyebabkan 2 hal:

i. Disc mengayun (swing) terhadap posisi seat, sehingga lama kelamaan posisi disc akan berubah terhadap seat sehingga apabila valve menutup maka disc tidak akan berada pada posisi yang tepat, sehingga bisa menyebabkan passing.

ii. Akan terjadi pengikisan (erosion) pada badan disc.

2. Globe valve

Beberapa contoh valve yang termasuk dalam jenis Globe valve:

i. Angle valve

Contoh gambar Angle valve

Termasuk jenis globe valve, digunakan untuk mengubah aliran sebesar 90 derajat. Valve ini bisa digunakan juga sebagai pengganti elbow:

ii. Needle valve

Contoh gambar Needle valve:

Termasuk jenis globe valve, digunakan untuk mengatur secara lebih akurat aliran yang pressure rendah. Bentuk disc nya panjang dan kecil seperti paku.

Globe valve adalah jenis valve yang dirancang untuk mengatur besar kecilnya aliran fluida (regulate atau trotthling). Pada dasarnya bagian utama dari Globe valve ini sama saja dengan Gate valve. Yaitu terdiri dari body, seat, disc, bonnet, stem, packing dan gland.

Globe valve dengan gate valve bentuknya hampir sama, tetapi ada ciri-ciri tertentu yang dapat di jadikan acuan untuk membedakan antara keduanya, yaitu:

i. Pada bagian dalam valve, disc dan seat nya berbeda. Perbedaan disc dan seat ini menyebabkan terjadi profil (pola) aliran yang berbeda. Bentuk dari disc dan seat inilah yang menyebabkan globe valve dapat diandalkan sebagai throttling valve. Aliran fluida saat melewati globe valve akan mengalami sedikit hambatan sehingga akan terjadi pressure drop yang lebih besar dari gate valve, pertama aliran akan mengenai seat lalu membelok keatas melewati dan mengenai seluruh bagian disc, lalu aliran akan dibelokkan lagi ke arah yang sama.

Seperti yang terlihat dibawah ini:

ii. Pada bagian luar, body dari globe valve terlihat lebih menggelembung.
Seperti yang terlihat pada gambar dibawah ini:

Khusus untuk globe valve yang menangani fluida steam, maka biasanya valve akan dilengkapi dengan back seat yang terletak berhadapan dengan seat. Back seat ini berperan sebagai pelapis pelindung bagian atas globe valve mencegah steam untuk menerobos masuk.

3. Rotation valve

Yang termasuk jenis Rotation valve adalah: Plug valve, Ball valve dan Butterfly valve.

Contoh gambar Plug valve

Contoh Gambar Ball valve

Contoh Gambar Butterfly valve

Dikatakan rotation valve karena valve membuka dan menutup dengan cara rotasi pada disc. Valve – valve dibawah ini berbeda dengan gate valve dan globe valve dalam hal cara membuka dan menutup valve. Pada gate valve dan globe valve, kita diharuskan memutar handwell, namun untuk rotation valve, kita bisa membuka dan munutup valve hanya dengan memutar handle valve sebesar 90 derajat. Oleh karena itu valve jenis ini bisa membuka dan menutup lebih cepat dari gate valve ataupun globe valve.

Handle pada valve tipe ini adalah pengganti handwell pada gate valve dan globe valve. Hal penting yang harus diperhatikan adalah, pada posisi valve fully open maka handle akan searah dengan aliran atau pipa, namun jika posisi valve fully close maka posisi handle tidak searah dengan aliran atau pipa, melainkan akan membentuk sudut 90 derajat dengan aliran atau pipa.

i. Plug Valve

Secara umum, kegunaan dari plug valve adalah untuk fully open dan fully close (isolation atau on/off control).

Bagian – bagian utama plug valve sama saja dengan gate valve ataupun globe valve. Yaitu body, stem, packing bolt, seal, plug. Seal sama fungsinya dengan packing, packing bolt sama fungsinya dengan gland nut atau gland, sedangkan plug sama fungsinya dengan disc tapi bentuknya berbeda.

Plug ini digunakan untuk mengontrol (membuka dan menutup) aliran pada plug valve, plug mempunyai celah atau lubang tempat aliran lewat. Saat handle diputar menuju open position maka plug akan berputar secara rotasi terhadap seat dan bagian yang bercelah akan melewatkan aliran. Namun pada saat handle diputar pada close position maka plug akan berputar secara rotasi terhadap seat dan bagian yang tak bercelah akan menahan aliran, sehingga aliran pun akan berhenti.

Plug harus rapat dengan body, agar tidak terjadi kebocoran ( leaking ) atau passing. Antara plug dan body akan terjadi gesekan (friction), maka untuk menimalkan efek gesekan tersebut, pada daerah sentuhan plug dan body diberikan pelumas.

Karena itu ada type plug valve yang mempunyai tempat pengisian pelumas diatas stem, ada juga yang sudah diberikan pelumas dari pabrik pembuatnya, ada juga yang yang tidak membutuhkan pelumas namun pada daerah sentuhan sudah dilapisi material teflon, jenis ini dinamakan self lubricating.

Jenis – jenis valve yang lain yang masih termasuk plug valve adalah:

a. Three way plug valve

Yaitu jenis plug valve yang mempunyai 3 port (sambungan), 1 untuk inlet dan 2 untuk outlet. Dengan menggunakan valve ini maka dengan mudah kita dapat mengarahkan outlet kearah aliran/pipa yang dikehendaki.

b. Four way plug valve

Biasa digunakan pada fluida cooling water yang melewati heat exchanger, dimana aliran cooling water bisa dengan mudah dibalikkan arahnya dengan tujuan untuk membersihkan heat exchanger tersebut dari kotoran-kotoran (fouling, sediment, solids).

ii. Ball valve

Secara sederhana, Ball valve sama saja dengan plug valve, tetapi bentuk disc nya berbeda. Dinamakan Ball valve karena bentuk disc nya ini bulat seperti bola, dan bentuk body nya silinder.

Ball valve digunakan juga sebagai on/off valve, fully opened atau fully closed valve, dan handal untuk aliran fluida yang mengandung partikel-partkel solid (slurry).

Sama seperti plug valve, ball valve juga membuka dan menutup dengan cara rotasi pada disc sehingga dapat membuka dan menutup lebih cepat. Ball valve juga mempunyai handle yang sama dengan plug valve, dimana pada posisi valve fully open maka handle akan searah dengan aliran atau pipa, namun jika posisi valve fully close maka posisi handle tidak searah dengan aliran atau pipa, melainkan akan membentuk sudut 90 derajat dengan aliran atau pipa.

iii. Butterfly valve

Butterfly valve digunakan untuk mengontrol (trhottling/regulate valve) aliran fluida yang bertekanan rendah.

Bagian-bagian utama pada valve ini sama saja dengan valve-valve yang diatas, yaitu body, disc, seat, dan handle. Disc nya berbentuk piringan yang tipis. Seat nya, melingkar mengikuti bentuk disc. Handle nya berbeda dengan type plug valve dan ball valve, karena mempunyai lever yang harus kita tekan apabila ingin membuka dan menutup valve dan kita lepaskan apabila telah sampai ke posisi yang kita inginkan. Lever inilah yang akan membantu disc untuk mengunci rapat.

Di bagian bawah handle dan lever terdapat skala (scale) yang digunakan untuk pembacaan posisi valve opening atau valve closing.

Butterfly valve juga membuka dan menutup dengan cara rotasi pada disc sehingga dapat membuka dan menutup lebih cepat. Dan mempunyai handle yang sama dengan plug valve, dimana pada posisi valve fully open maka handle akan searah dengan aliran atau pipa, namun jika posisi valve fully close maka posisi handle tidak searah dengan aliran atau pipa, melainkan akan membentuk sudut 90 derajat dengan aliran atau pipa.

4. Diaphgram valve

Gambar Diaphgram valve

Diaphgram valve bisa digunakan untuk mengatur aliran (trhottling) dan bisa juga digunakan sebagai on/off valve. Diaphgram valve handal dalam penanganan material kasar seperti fluida yang mengandung pasir, semen, atau lumpur, serta fluida yang mempunyai sifat korosif.

Diaphgram valve mudah dikenali karena bentuk bonnet nya yang menggembung seperti lonceng. Diaphgram valve mempunyai stem, handwell, plunger dan diaphgram stud yang menjadi satu, diaphgram, seat dan body. Diaphgram valve tidak mempunyai disc, tetapi sebagai pengganti disc adalah diaphgram itu sendiri. Dimana valve ini akan menutup jika plunger menekan diaphgram, dan akan terbuka jika plunger naik keatas. Saat menutup valve ini, juga tidak boleh terlalu kencang, karena bisa merusak diaphgram.

5. Pinch valve

Gambar Pinch valve

Pinch valve digunakan untuk menangani fluida yang berlumpur, endapan, dan yang mempunyai partikel-partikel solid yang banyak serta fluida-fluida yang mempunyai kecenderungan untuk terjadi kebocoran (leak).

6. Check valve

Check valve digunakan untuk membuat aliran fluida hanya mengalir kesatu arah saja atau agar tidak terjadi reversed flow/back flow.

Bentuk check valve sama saja dengan gate valve tapi valve ini tidak mempunyai handwell/handle maupun stem.

Secara umum ada 3 macam check valve yang cara kerjanya sama saja namun aplikasi nya terhadap material fluida yang berbeda. yaitu: Swing check valve, Lift check valve, dan Ball check valve.

Contoh Gambar Swing check valve

Contoh Gambar Lift check valve

Contoh Gambar Ball check valve.

Swing check valve, penggunaan untuk fluida gas ataupun liquid yang tidak mengandung partikel padat (solid)

Lift check valve, penggunaan untuk fluida steam, gas, maupun liquid yang mempunyai flow yang tinggi

Ball check valve, penggunaan untuk fluida liquid yang mengandung partikel padatan.

7. Relieve valve dan Safety valve

Contoh gambar Relieve valve dan Safety valve

Kedua valve ini digunakan untuk melepaskan (release) tekanan (pressure) pada suatu sistem agar tidak membahayakan alat (equipment), personnel yang sedang bekerja, dan untuk kepentingan proses itu sendiri.

Antara kedua valve ini terdapat penggunaan istilah yang seringkali tertukar satu sama lain. Kadang Relieve valve dianggap Safety valve dan kadang juga Safety valve dianggap Relieve valve. Namun, sebenarnya perbedaan mendasarnya adalah cara kerjanya itu sendiri, Relieve valve akan membuka perlahan-lahan apabila terjadi kelebihan (excess) pressure dan akan menutup kembali apabila pressure telah kembali normal. Relieve valve lebih cocok diaplikasikan ke fluida liquid. Sedang Safety valve, akan membuka secara sangat cepat langsung 60% opening apabila terjadi excess pressure. Dan akan menutup kembali hanya apabila pressure telah berada dibawah pressure normal (set point). Safety valve sangat cocok diaplikasikan ke fluida gas.

IV. Permasalahan dan solusinya

1. Valve leak/bocor

Jika valve tidak bekerja dengan baik maka kemungkinan besar terjadi leak. Bagian yang paling sering terjadi leak adalah pada packing gland. Hal ini bisa diatasi dengan mengencangkan Gland nut. Setelah itu maka periksa kembali putaran handwell, karena setelah mengencangkan gland nut maka akan terjadi gesekan antara packing dengan stem yang menyebabkan handwell susah di gerakkan.

Kebocoran juga biasa terjadi didaerah sambungan body dan bonnet, daerah body, dan disekitar flange.

2. Kerusakan Fisik

Valve yang tidak bekerja dengan baik kemungkinan juga disebabkan karena adanya kerusakan fisik pada valve itu sendiri, oleh karena itu pemeriksaan fisik sangat penting untuk dilakukan lebih dahulu sebelum adanya perlakuan yang lebih jauh.

3. Pemberian Pelumas

Pemberian pelumas pada valve terutama pada stem, sangat penting untuk menjaga ketahanan valve.

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