ASTM D6973 Standard Test Method for Indicating Wear Characteristics of Petroleum Hydraulic Fluids in a High Pressure Constant Volume Vane Pump
6. Apparatus
6.1 The basic system consists of the following (see Fig. 1):
6.1.1 Electric Motor, or other suitable drive, capable of a rotational speed of 2400 r/min with 93 kW (125 hp) as suggested minimum power requirement (see Fig. 1, Item 5).

6.1.2 Test Stand Base, with appropriate, rigid mounting for the motor, pump, reservoir, and other components.

6.1.3 Rotary Intra-Vane Pump, replaceable cartridge type, Vickers 35VQ25A-11*20 (Cartridge Kit P/N 4998040-002) rated at 81 cm3/rev (4.98 in. /rev) flow at 1200 r/min. A protective shield around the pump is recommended.
6.1.3.1 There are to be no modifications to the pump housing.

6.1.4 Reservoir, equipped with a baffle and lid, all of stainless steel construction.
6.1.4.1 Additional fluid ports may be added to the reservoir as required by the user to assist in measuring fluid level, reservoir temperature, and so forth.

6.1.4.2 If the reservoir is positioned so that the contents cannot be visually checked for air entrainment by removing the lid, a fluid-sight glass viewing port may be located in the side of the reservoir.

6.1.5 Pump Outlet Pressure Control Valve, with either manual or remote control (see Fig. 1, Item 7).

6.1.6 Temperature-control Device, suitable for controlling coolant flow to the heat exchanger to maintain test fluid at the specified temperature (see Fig. 1, Item 9).

6.1.7 Temperature Indicator, (see Fig. 1, Item 2) shall have a minimum accuracy of +/- 1 °C and shall have an appropriate sensor to monitor pump inlet temperature.
6.1.7.1 To prevent a flow disturbance near the pump inlet port, the temperature probe shall have a diameter of not more than 6 mm (0.25 in.) and positioned not less than 30 cm (12 in.) from the pump inlet port.

6.1.7.2 The test fluid temperature probe shall be positioned greater than 30 cm (12 in.) from the pump inlet cover (see Fig. 2). The fluid temperature probe shall be inserted into the midpoint of flow.

6.1.8 Heat-Exchanger, (see Fig. 1, Item 9). The heat exchanger should be of adequate size and design to remove the excess heat from the test system when utilizing the available coolant supply.

6.1.9 Outlet Pressure Indicator, (see Fig. 1, Item 6), to measure pump discharge pressure, and shall have an accuracy of at least +/- 100 kPa (+/- 15 psi).

6.1.10 Inlet Pressure Indicator, (see Fig. 1, Item 3), to measure pump inlet pressure, and shall have an accuracy of at least +/- 7 kPa (+/- 1 psi).

6.1.11 Filter Unit, (see Fig. 1, Item 8), to limit system debris from causing wear to the test pump. The filter performance should be β3 ≥ 100.
6.1.11.1 The filter housing shall be installed with dual pressure gages (see Fig. 1, Item 13) or a differential pressure transducer to monitor pressure across the filter to warn of impending collapse of the element.

6.1.11.2 If dual pressure gages are used to monitor filter pressure, the rated collapse pressure of the filter element should be known.

6.1.12 Flow-Measuring Device, (see Fig. 1, Item 12), with an accuracy of at least +/- 1 L/min (+/- 0.25 gpm).
6.1.12.1 It is suggested that the test circuit be equipped with some automated shutdown capabilities for safety reasons. Safety relays could be any of the following: low-level, high pressure, high temperature, and low flow safety switches incorporated into the system.

6.1.12.2 A check should be made to ensure that the flush and test fluid are compatible with seals or any other materials in the system.

6.1.13 Flexible Motor Coupling, to connect the motor drive and the pump.

6.1.14 Fluid Sampling Port, in accordance with ISO 4021.

6.2 The various components of the test system shall be placed in the system as indicated in Fig. 1.
6.2.1 The test system shall be arranged and provided with necessary drain valves so that complete draining is possible with no fluid trap areas.

6.2.2 Good hydraulics piping practices should be used when constructing the test system to avoid air entrainment points and flow restrictions.

6.2.3 The pump should be mounted so that its internal surfaces can easily be inspected and cleaned, alignment can be checked, and the operator has comfortable access when torquing the head.

6.2.4 A pressure transducer, to measure inlet pressure, shall be placed within 30.5 cm (12 in.) of the opening of the pump cover.

6.2.5 The inlet pressure of the pump shall be 13.8 kPa +/- 7 kPa (2 psig +/- 1 psig) once the break-in procedure is complete and test conditions have been met (see 12.2).

NOTE 1 - See Annex A1 for recommended testing conditions for water-based synthetic fluids.

6.2.6 The reservoir should be mounted so that it can be cleaned and filled with ease and the contents may be readily inspected by removal of the reservoir lid or inspection cover.

6.2.7 The inlet line (from the reservoir to the pump intake) shall have an internal diameter of at least 5.08 cm (2 in.) and shall have a straight run of at least 61 cm (24 in.) to the pump inlet port.

NOTE 2 - Some users prefer to use a radius bend at the reservoir outlet instead of an elbow. If used, the straight run described in 6.2.7, shall still be measured between the end of the bend and the pump inlet port.

6.2.8 The high pressure discharge line (from the pump to the pressure control valve) shall have a minimum inside diameter of 31.75 mm (1 1/4 in.) with a maximum allowable working pressure rating greater than 20.7 MPa (3000 psi). A seamless steel pipe with a 60 mm outside diameter and 11.1 mm wall thickness (2 in. double extra strong pipe-XXS) or equivalent high-pressure hose (SAE 100R13-20) are recommended for the discharge line.

6.2.9 The fluid return line and fittings (from the pressure control valve to the filter, flowmeter, heat exchanger, and reservoir) should have a minimum inside diameter of 2.54 cm (1 in.). A seamless steel pipe with 33 mm outside diameter and 3.4 mm wall thickness (1 in. Schedule 40) is recommended for the fluid return line.

6.2.10 A shut-off valve may be located in the plumbing between the reservoir and the inlet to the pump. The full flow valve shall have a minimum orifice diameter of 5.08 cm (2 in.) and shall be positioned no closer than 30 cm (12 in.) from the pump inlet port.

NOTE 3 - Some users find the addition of a shut-off valve on the return line to be a useful addition to the piping since it allows filter changes and other system maintenance to be performed without draining the reservoir. (Warning - If a shut-off valve is installed in the fluid return line, the user shall take procedural steps to ensure that this valve has been opened before the pump is started. If the valve is not opened, low pressure system components may rupture.)

7. Reagents and Materials
7.1 (Warning - Use adequate safety provisions with all solvents.)

7.2 Aliphatic Naphtha, Stoddard solvent or equivalent is satisfactory. (Warning - Combustible. Vapor harmful.)

7.3 Precipitation Naphtha. (Warning - Extremely flammable. Harmful if inhaled. Vapors can cause flash fire.)

7.4 Isopropanol. (Warning - Flammable, vapor harmful in large amounts, eye irritant, extremely combustible when hot.) (Warning - In instances when the solvents listed in Section 7 are not effective, alternative solvents may be used. It is the responsibility of the user to determine the suitability of alternative solvents and any hazards associated with their use.)