ASTM D6973 Standard Test Method for Indicating Wear Characteristics of Petroleum Hydraulic Fluids in a High Pressure Constant Volume Vane Pump
12. Procedure
12.1 Break-in:
12.1.1 Install the 35VQ25A-11*20 pump.

12.1.2 Jog the pump to release any entrained air that is in the system.

12.1.3 Set the pump speed to 2400 r/min +/- 20 r/min, pump outlet pressure = 6.9 MPa +/- 0.2 MPa (1000 psig +/- 20 psig), and run for 30 min. Allow the pump inlet temperature to rise and not exceed 52 °C +/- 3 °C (125 °F +/- 5 °F).

12.1.4 Set the pump speed to 2400 r/min +/- 20 r/min, pump outlet pressure = 13.8 MPa +/- 0.2 MPa (2000 psig +/- 20 psig), and run for 30 min. Allow the pump inlet temperature to rise and not exceed 79 °C +/- 3 °C (175 °F +/- 5 °F).

NOTE 6 - See A1.4.1 for recommended break-in procedure for water-based synthetic fluids.

NOTE 7 - It is recommended that the temperature in each stage of break-in meet conditions in 15 min or less.

12.2 Performance Testing:
12.2.1 Set the pump speed to 2400 r/min +/- 20 r/min, pump outlet pressure = 20.7 MPa +/- 0.2 MPa (3000 psig +/- 20 psig), and run for 49 h. Allow the pump inlet temperature to rise and not exceed 95 °C +/- 3 °C (203 °F +/- 5 °F).

12.2.2 The minimum pump flow is 132.5 L/m (35 gpm). The test should be stopped if the pump flow falls below the minimum specification.

NOTE 8 - See A1.4.2 for recommended performance testing procedure for water-based synthetic fluids.

12.3 Restarting A Test:
12.3.1 If for any reason a test is stopped before 50 h, the test can be resumed after the test conditions are established once again. Set the pump speed to 2400 r/min +/- 20 r/min, pump outlet pressure = 6.9 MPa +/- 0.2 MPa (1000 psig +/- 20 psig), and run for 30 min. Raise the pump inlet temperature to 52 °C +/- 3 °C (125 °F +/- 5 °F).

12.3.2 Set the pump speed to 2400 r/min +/- 20 r/min, pump outlet pressure = 13.8 MPa +/- 0.2 MPa (2000 psig +/- 20 psig), and run for 30 min. Raise the pump inlet temperature to 79 °C +/- 3 °C (175 °F +/- 5 °F).

12.3.3 Set the pump speed to 2400 r/min +/- 20 r/min, pump outlet pressure = 20.7 MPa +/- 0.2 MPa (3000 psig +/- 20 psig). Raise the pump inlet temperature to 95 °C +/- 3 °C (203 °F +/- 5 °F). The test timer can resume from the point that it left off only when test conditions have been reestablished. Then run for the balance of the 49 h remaining at the point the test was interrupted.

12.3.4 Once test conditions have been met, the flow rate at restart cannot be lower than 5 % of the last recorded flow for the test results to be valid.

12.4 Test Shutdown:
12.4.1 After completion of the test, draw off a fluid sample, in accordance with ISO 4021, to determine the fluid cleanliness in accordance with ISO 4406.

12.4.2 Reduce the pressure control valve setting and stop pump operation.

12.4.3 Stop the flow of the cooling water.

12.4.4 Observe and record the condition of the test fluid, noting any unusual appearance or odor.

12.4.5 Open all drain valves and drain the test system.

12.4.6 After the pump has cooled sufficiently, remove the pump cover and carefully remove the test cartridge.

13. Disassembly and Inspection
13.1 Disassembly:
13.1.1 When a test has been completed at 50 h, disassemble the 35VQ25A-11*20, Fig. 2.

13.2 Mass Loss Measurements and Inspection:
13.2.1 Using a solvent, thoroughly clean the cam ring and set of ten vanes. Allow the cam ring and vanes to dry. Determine the mass of the pump cam ring and the mass of the ten vanes (separately) to the nearest milligram.

13.2.2 Determine the loss of mass of the pump cam ring and ten vanes, sustained during pump operation, by subtracting the post-test masses from the pre-test masses.

13.2.3 Inspect the pump components for any unusual wear.