ASTM D6973 Standard Test Method for Indicating Wear Characteristics of Petroleum Hydraulic Fluids in a High Pressure Constant Volume Vane Pump
4. Summary of Test Method
4.1 Hydraulic fluid in the amount of 190 L +/- 4 L (50 gal +/- 1 gal) is circulated through a rotary vane pump system for 50 h at a pump speed of 2400 r/min +/- 20 r/min and a pump outlet pressure of 20.7 MPa +/- 0.2 MPa (3000 psig +/- 20 psig). Fluid temperature at the pump inlet is 95 °C +/- 3 °C (203 °F +/- 5 °F). An ISO Grade 32 or 10W viscosity is required.
4.2 The mass of the cam ring and all ten vanes should be individually determined before and after the test. The mass loss of the cam ring should be reported with the combined mass loss of all ten vanes. The intra-vanes (inserts) are not part of the required mass loss measurements and should be separately measured if desired. Other reported values are fluid cleanliness before and after the test, initial flow rate, and final flow rate.
4.3 Prior to installing the hydraulic test fluid into the rig, a stand flush is required to remove any contaminants. A minimum quantity of 190 L +/- 4 L (50 gal +/- 1 gal) of fluid (see Note 1) made of the same chemical formulation as the test fluid, is required for the stand flush. Therefore the total quantity of oil required for the test is 380 L (100 gal).
5. Significance and Use
5.1 This test method is an indicator of the wear characteristics of petroleum hydraulic fluids operating in a constant volume vane pump. Excessive wear in vane pumps could lead to malfunction of hydraulic systems in critical industrial or mobile hydraulic applications.
