Pump Test Procedure For Evaluation Of Antiwear Fluids For Mobile Systems

Test Pump
35VQ25A-11*20 (Cartridge Kit P/N 413421)

Test Conditions
Speed: 2350-2400 rpm
Outlet Pressure: 205-210 bar gage, (2975-3025 psig)
Inlet Pressure: 0-.15 bar gage, (0-2 psig) with flooded inlet
Inlet Temperature: 90-96degC (195-205degF)

Operating Mode
Steady-state pressure at above rated conditions for 50 hours. Terminate test if flow degradation exceeds 7.5 L/min (2 gpm) prior to the completion of the 50-hour test. Such terminations are not considered to be failures since this flow degradation can be due to causes other than excessive wear, such as erosion on the side plates resulting from insufficient inlet pressure.

Initial Fluid Condition
Water Content: .075% maximum Contamination Level: ISO Code 18/16/14 or better particle count. Alternatively, 30 mg/liter maximum gravimetric contamination (using filter membrane of 0.8 micrometer porosity).

Pump Break-In Procedure
1. Increase pump speed to test level and apply 70 bar gage (1000 psig) outlet pressure. When inlet temperature of approximately 50degC (125degF) is achieved, maintain it for elapsed time of 1/2 hour at pressure.

2. Increase pressure to 140 bar gage (2000 psig). When inlet temperature of approximately 80degC (175degF) is achieved, maintain it for elapsed time of 1/2 hour at pressure.

3. Increase pressure to 205-210 bar gage (2975-3025 psig). When temperature stabilizes at 90-96degC (195-205degF), record operating parameters, including flow. Terminate test if flow is below 136 L/min (36 gpm) after five hours of operation. With production tolerances, low flow sometimes occurs while pumping light fluids. This condition tends to increase the wear rate.

Test Duration
Continue operation of the unit for 50 hours total (including break-in time), periodically monitoring operation parameters.

Number Of Cartridges
Evaluation requires a minimum of three pump cartridges. The fluid should not be changed during the total 150-hour test period.

Accept/Reject Guidelines
1. Total weight loss of all vanes from individual cartridge tested should be less than 15 mg (not including intravanes).

2. Weight loss of ring from individual cartridge tested should be less than 75 mg.

3. Regardless of weight loss measurements, the pump parts, especially the rings, should not have evidence of unusual wear or stress in contact areas. There may be instances when unsatisfactory performance is indicated even though the weight loss is low; for example, galling or excessive burning would not show as excessive weight loss but would be unacceptable.

When any one cartridge out of three fails for any reason, two more cartridges should be tested. In this case, four of the five tested cartridges must meet the above accept/reject guidelines. This procedure is offered only as a fluid screening method. Successful completion of this test does not constitute endorsement or approval of fluids by Vickers.

Test Circuit


Description of Components
1. Reservoir (50 gallons minimum; elevated above pump centerline to provide gravity feed)
2. Temperature gage or thermocouple
3. Inlet pressure gage
4. Pump: 35VQ25A-11*20 (cartridge kit P/N 413421)
5. Electric motor (125 HP)
6. Outlet pressure gage
7. Pressure relief valve
8. Filter (10 micrometer nominal)
9. Cooler
10. Flow meter