30 Mar 21
ALPHA LUBRICATION SYSTEM ACCUMULATOR N2 CHARGE
CHECKING PRESSURE OF THE ALPHA LUB ACCUMULATORS
With reference to MAN B&W Service Letter SL2016-632, it is recommended that, as a minimum, the accumulators are refilled every 2,000 operating hours. Additionally, the pressure drops across the filters in the pump station should be monitored at the intervals specified in the standard manual.
In the Alpha lubrication system, two types of accumulators are used: 0.16 ltr on the low-pressure side and 0.75 ltr on the high-pressure side.
The pressure of the small accumulators should be adjusted to 1.5 bar, while the large accumulators should be adjusted to 30 bar.
The following provides basic guidance for checking and adjusting the pressure of the Alpha lubrication system accumulators.
1. Remove the protection cover of the accumulator gas side valve.
2. Slightly lose the accumulator plug (gas side valve) with 6mm allen wrench. Never lose the plug with the charge kit which will cause damage of the kit.
3. Connect the charge tool and tight with hand only.
4. Connect reducer to N2 bottle.Connect hose from bottle to charge tool.
5. Install small range pressure gauge for small accumulator and high range pressure gauge for big accumulator. Make sure vent valve(1) and charge valve(2) closed.
6. Adjust reducer to 1.5 bar for small accumulator and 30 bar for big accumulator and open gas filling valve(2), if required you can increase the pressure through reducer. If you need to decrease the pressure you can close the bottle and open the vent valve(1) slightly until required pressure obtained.
7. After adjusting the pressure, close the gas filling valve by hand and remove the charging tool. Tight the plug with 30Nm torque.
It is also possible to check/adjust the pressure in place, if you can make sure oil pressures on the accumulator is zero.
If you don’t have regulator-charge tool and gas bottle* on board, don’t worry we can supply them at a compatible price.
