Fuel transfer and booster pumping moves a large volume of a flammable fluid across a ship, and its control logic decides when that is safe. Overpressure protection, tank level interlocks, line-up confirmation and leak detection all have to work before the pump is allowed to run. Because the consequences of a control failure here are a fire or a pollution, the panel and the fuel oil system arrangement are inspected as one safety case.
Key facts and acceptance criteria
The table below lists the values that decide whether the system passes at survey and at maintenance. They come from the maker documentation and the applicable rules, not from general practice, and they are the numbers a surveyor checks.
| Parameter | Requirement | Reference |
|---|---|---|
| Overpressure trip | Independent of the control system; set per the maker | SOLAS II-1/30 and maker manual |
| Tank level interlock | Pump inhibited outside the permitted tank level range | Maker technical manual |
| Line-up confirmation | Suction and discharge valves proven before the pump runs | Maker technical manual |
| Leak detection | Line leak detection proved and annunciated | SOLAS II-1/37 |
| Overboard discharge | High level alarm and no discharge while the overboard is closed | MARPOL Annex I |
Regulatory and technical basis
SOLAS Chapter II-1 regulations 37 on fuel oil systems, regulation 38 on oil fuel delivery, MARPOL Annex I on the discharge of oil and oily mixtures, the maker technical manual, and the class survey plan. Fuel oil system arrangement, the overboard discharge arrangement and the fuel line integrity are examined at the annual survey.
What the service assessment covers
Seanav Marine provides independent service assessment. The following items define a starting scope for a competent service assessment. The actual test method and acceptance criteria come from the installed equipment documentation and the agreed job scope.
- Transfer, booster and fuel oil pump start, stop and sequencing verification
- Overpressure trip, relief arrangement and pressure switch testing
- Tank level interlocks, high level alarms and pump permissive logic checks
- Line-up, valve position feedback and pump permissive confirmation testing
- Line leak detection testing and oil mist or leak detection system proving
How the work is planned and executed
- Arrangement review. Establish the fuel oil system arrangement, the transfer sequence, the maker trip schedule and the leak detection arrangement before any test.
- Permissive proof. Prove each permissive the pump depends on, by simulating the conditions that should inhibit the pump and confirming the alarm.
- Trip and leak test. Prove the overpressure trip to the final actuation and test the line leak detection under the maker procedure.
- Restore and report. Restore the approved settings, repeat the proving tests and issue the record with the as-found and as-left values and the outstanding defects.
Failures that must be distinguished before testing
Do not widen a setpoint or suppress an indication without an engineering assessment. The following failure modes have to be separated from a genuine plant fault before a conclusion is drawn, because they are common, they are visible, and they are usually the cheaper explanation.
- Overpressure trips set high enough that the relief valve lifts before the trip acts
- Pump permissives that no longer match the actual tank and line-up, allowing a pump to run against a closed line
- Line leak detection that is inhibited or bypassed after a false activation
Equipment and OEM compatibility
Replacement parts and calibration methods must come from the original manufacturer. Seanav Marine works with Kongsberg and ABB fuel transfer control, Siemens and Emerson marine systems, Sulzer and Albright pump sets, and maker-specific overpressure and leak detection systems. and sources parts through authorised distributor channels.
Frequently asked questions
What is the overpressure trip on a fuel booster pump?
A safety device that stops the pump when the discharge pressure exceeds a set limit, independent of the control system. It protects the pipework, the hoses and the tank against the pressure that a closed valve or a blocked line would create.
Why must the line-up be confirmed before the pump starts?
Because the consequence of a wrong line-up is a transfer into a closed line or from a wrong tank. The control system normally verifies the valve positions and the level before it grants the pump a permissive, and that verification is part of the test.
How is line leak detection proven?
By the maker method, which normally involves a simulated leak or a test function that confirms the sensor circuit, the alarm and the pump action. The test must not be run with live fuel in the line unless the maker procedure permits it.
Does a fuel transfer arrangement need class survey attention?
Yes. The fuel oil system arrangement, the safety devices and the overboard discharge arrangement are examined at the annual survey, and any change to the arrangement may need the maker or approval-body review first.
Reference framework
These sources explain the relevant system or regulatory context. They do not replace the installed equipment manual or prove the applicability of a particular rule to every vessel.
service@seanav.org · +971 58 568 1197 · Contact the operations desk
About this guide
Published by Seanav Marine. Editorial and source review: . This general service guide is based on the references shown; it is not a signed vessel-specific engineering procedure. Equipment manuals and the responsible technical personnel determine the job requirements.
For technical assessment or a factual correction, contact Seanav Marine with the equipment identity and supporting documents.