Wednesday, January 8, 2020

Hydraullic pressure testing of bunker lines

As per USCG & OCIMF requirements a hydrostatic pressure testing of the
bunker lines should be performed, annually to 100% and twice in a five year
period to 150% of the Maximum Allowable Working Pressure
The annual tests of 100% MAWP should be performed utilizing the FO
transfer pump to build up the required pressure. However, for the test of
150% MAWP twice in a five year interval, when the ship is not required to
be at a drydock (at 2.5 and at 7.5 years) the following alternative method of
testing may be used: Fill the bunker piping with fuel utilizing the FO transfer
pump (gear type) and then use air to build up the required pressure.
A typical bunker line testing will be at 5Bar or 7Bar annually and at 7.5 Bar
or 10.5Bar twice in a five year period. Testing pressure used and date must
be recorded in the Engine Log Book and Deck Log Book. At the end of the
testing any final quantity of fuel oil transferred from storage tank to the
settling tank must be also recorded in the Oil Record Book under code
The involvement of both engine and deck departments is required. A risk
assessment along with a work planning meeting should be contacted prior to
the testing and as a result a ship specific sketch with the FO piping and
valves must be prepared. 
Preparation for the bunker line testing 
1) Identify the safety valve setting of the fuel oil transfer pump (check the 
2) Ensure that bunker piping fittings and components such as valves, 
flanges, gauges etc. can withstand the test pressure. 
3) Minimum of three (3) officers with Walkie Talkies are needed for the test. 
The Chief Engineer should be the team leader. 
• one officer at the transfer pump monitoring the gauge 
• one officer at the filling valve to settling tank, monitoring the level of 
the settling tank 
• one on deck monitoring the line gauge. 
4) Confirm that the pressure gauges on transfer pump and deck line are fully 
functional and calibrated. 
5) The settling tank must not be full, thus select the time just before the 
transfer pump starts in auto mode for filling the settling Tank
Bunker line testing
1. Close all the valves, which deliver fuel to port and starboard F.O. 
storage tank(s). 
2. Change over the transfer pump to manual mode, when the level in 
settling tank is low. 
3. Confirm the valve for filling the settling tank is open. 
4. Open the valve to send the fuel on deck. 
5. Make sure the independent valves for delivery is closed with blank. 
6. Confirm by the walkie talkie all 3 in position and 
7. Start the transfer pump. In the beginning the pressure is very low due 
the fuel escape to settling Tank. 
8. The officer in filling valve should slowly start to close the valve, always 
monitoring the pressure in pump location and in deck line, with the 
other 2 officers. 
9. When the safety valve opens, remove protector cover and slowly tighten 
the bolt of safety valve, observing carefully the pressure, until desired 
pressure is achieved. 
10. Continue to close the valve easy till the pressure on deck is at the desired 
testing pressure; keep and secure the filling valve in this position for 
about 10 minutes. 
11. The bunker pipelines should be thoroughly examined for any leakages 
12. Monitor the level of settling tank to stop the pump before overflow. 
13. After completion of the inspection readjust/loosen slowly the safety valve 
at maker’s set pressure and reinstall the protector cover. 
14. After completion of the testing stop the pump and return all the valves in 
normal position and change over the transfer pump to auto mode. 
15. Testing pressure used and date must be stenciled on the bunker line on 
deck. Note that last date of both 100% MAWP and 150% MAWP must 
be stenciled.
1. If the pressure gauge indication on the deck is 7,0Bar the local gauge in 
transfer pump will indicate about 8.5Bar. This is normal due to the 
difference of about 15 meters between deck line and pump location. 
2. During testing close easy and very carefully the filling valve to settling 
tank because the transfer pump is gear type and very easily can build a pressure up very high pressure.

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