ASTM D7043 Standard Test Method for Indicating Wear Characteristics of Non-Petroleum and Petroleum Hydraulic Fluids in a Constant Volume Vane Pump
8. Test Stand Maintenance
8.1 Sensors and shut-off switches should be checked periodically for proper calibration and operation in accordance with good engineering practice as determined by the user.

8.2 It is recommended that the pump shaft (Item 17, Fig. 2; Item 2, Fig. 3), seals (Items 4, 15, 16, Fig. 2; Items 5, 7, 12, 15, Fig. 3), and bearings (Items 2, 13, Fig. 2; Items 3, 11, Fig. 3) be replaced after every five runs (or sooner if high weight loss, vibration, cavitation, or visual deterioration is encountered).
8.2.1 A variety of seal compounds is available for the pump. It is the responsibility of the user to determine the best seal composition to use with any given fluid. If possible, check the cure date of the seal.

8.3 Inspect the pump body and head.
8.3.1 Visually examine the pump head and the interior of the pump body (Items 3 and 11, Fig. 2; Items 1, 10, Fig. 3). Replace if evidence of deterioration is observed.

8.3.2 When the pump has been disassembled for seal and bearing replacement, carefully inspect the faces of the pump body and head which seal against the bushing faces (Surfaces A and B, Fig. 4) for high spots, warped condition, or other damage which may interfere with a good fluid seal. Discard any unsuitable components.

8.3.3 Check that the Eaton-Vickers head bearing (Item 2, Fig. 2) is a press fit into the head. If it is loose, discard the head. The B1 head bearing (Item 3, Fig. 3) should be a close slip fit to the head.

8.3.4 Check that the shaft bearing (Item 13, Fig. 2; Item 11, Fig. 3) makes a close slip fit into the body. If it is loose, discard the body.

8.3.5 Check that the bore for the cartridge (Diameter E, Fig. 4) is not greater than 76.23 mm.
8.3.5.1 If the bore is oversized, the ring may crack when the pump is pressurized.

8.3.5.2 If the bore is oversized, a piece of 0.025 mm shim stock trimmed to 20 mm by 235 mm can be wrapped around the ring to pack out the excess clearance. Installation of the shim requires that the cartridge assembly be made in the pump housing and that the housing bore and ring outside diameter are clean and dry.

8.3.6 Check that the pump body ports align properly with the bushing ports, with no overlapping, which might restrict fluid flow.

NOTE 11 - In some cases in which operational problems continue without apparent cause, a change of pump body or head, or both, has been known to alleviate the problem.

8.4 Inspect the shaft (Item 17, Fig. 2; Item 2, Fig. 3; Fig. 5). 8.4.1 Check that the splines of a new shaft are smoothly cut, have consistent width from the outer diameter to the root, and are parallel with the axis of the shaft. Avoid reusing shafts if the rotor has worn deep marks in the splines (Items 1, 2, 3, and 4, Fig. 5).

8.4.2 Check new shafts and used shafts that have been subjected to pump failure or overheating for bending, twisting, or damage to the key seat or splines (Items 5 and 7, Fig. 5).

8.4.3 Check the surface where the shaft seal rides for conditions that may cause the seal to leak (Item 6, Fig. 5).

8.5 Check alignment of the pump and motor shafts. Maximum values of 0.08-mm parallel misalignment and 0.3° angular misalignment are suggested limits.
8.5.1 Alignment checks should be made with a torqued cartridge in place.

8.5.2 Using a test indicator, inspect the shaft for a bent condition by rotating it by hand with the motor coupling removed (Item 7, Fig. 5).

8.5.3 Precision ground coupling halves that have identical outside diameters and run true to the shaft with which they are used (pump or motor) will permit the use of a straight edge and feeler gages to achieve close alignment of the pump and motor shafts.

8.6 Periodically clean the eight tapped holes that receive the pump head bolts and the threads of the head bolts themselves (Item 1, Fig. 2; Item 17, Fig. 3). The threads may be coated with a light oil to prevent corrosion. To ensure even torquing of the cartridge, housings or head bolts with damaged threads should be discarded.

8.7 Periodic disassembly of the relief valve (Item 8, Fig. 1) for cleaning and inspection is recommended.

9. Sampling
9.1 The sample of fluid shall be thoroughly representative of the material in question, and the portion used for the test shall be thoroughly representative of the sample itself.

10. Flushing
10.1 Proper cleaning and flushing of the entire system is extremely important to prevent cross-contamination of test fluids.

10.2 Flushing procedure for petroleum and synthetic fluids:

NOTE 12 - This flushing sequence is not adequate when changing fluid types such as from glycol to phosphate ester, oil to glycol, and so forth (see 7.5).

10.2.1 Drain all old fluid from the system, remove used test cartridge (if present), remove, and discard old filter. Wipe out pump and filter housings and the reservoir and baffle.

10.2.2 Install a flush cartridge (any good, previously used cartridge) and a new filter.

10.2.3 Close all drain valves and torque the pump head. Open the pump inlet and return line valves if used (see Notes 9 and 10).

10.2.4 Charge the system with 7.6 L of flushing fluid. For petroleum and synthetic fluids use either Stoddard solvent (Warning - see 7.2) or base stock depending on the similarity of the old and new test fluids.

NOTE 13 - One flush of this petroleum solvent is usually sufficient to clean a system in which an oil was run. Other solvents can be used when oxidized oil has coated the reservoir and lines (Warning - see 7.5). Repeat the flush if the first flush is cloudy or opaque.

10.2.5 Reduce the setting of the pressure control valve so that pressure will not be generated when flow starts.

10.2.6 Jog the pump drive motor ON and OFF switches to remove the air from the test system. Continue until the fluid returning to the reservoir is visually free of air.

10.2.7 Flush for 30 min at 0.7 MPa and 38 °C to 49 °C.

10.2.8 Drain system, remove filter element, and flush cartridge. Wipe out pump and filter housings and the reservoir and baffle.

10.2.9 Reinstall used filter element and flush cartridge, torque pump head, reduce setting of pressure control valve, close all drain valves, and open pump inlet and return line valves.

10.2.10 Recharge system with 7.6 L of test fluid.

10.2.11 Jog the pump drive motor ON and OFF switches to remove the air from the test system. Continue until the fluid returning to the reservoir is visually free of air.

10.2.12 Flush for 30 min at 0.7 MPa and 38 °C to 49 °C.

10.2.13 Completely drain the system of all fluid.

10.2.14 Remove the flush cartridge and wipe out the pump housing.

10.2.15 Remove and discard the used filter element, clean the filter housing, and install a new filter element.

10.3 Flushing procedures for water glycol and other water based fluids:
10.3.1 To clean the system for water glycol testing, disassemble the system, including the pump body, heat exchanger, (see Note 4), and relief valve.

10.3.2 Water rinse and clean rubber hoses by passing a bristle brush through the length of the hose several times. Then rinse hoses with water and dry with compressed air. Check hoses for cracking, hardening, and tackiness. Replace as needed.

10.3.3 Water rinse and dry other rubber parts and gaskets with compressed air. Check for wear, cracks, and tackiness. Replace as needed.

10.3.4 Clean metal parts by first rinsing with water, then scrubbing with a soft bristle brush, and rinsing with water again, and then blowing dry with air. If a shell-and-tube heat exchanger is used as described in Note 4. Clean the heat exchanger tubes with a brass rifle cleaning brush, or other brush suitable for the size of the tubes. Clean the metal tubing and holes in the castings with a test tube brush.

10.3.5 After water cleaning, place all metal parts in a solvent bath composed of a mixture of 50 % naphtha and 50 % isopropanol (Warning - see 7.2 and 7.4) and agitate for at least 30 min. Then drain the parts and dry with compressed air.

NOTE 14 - It is critically important not to wash pumps run with other fluids, for example, polyol esters and mineral oils, in the same bath used to clean pumps run with water glycol.

NOTE 15 - Hoses that have been previously used with mineral oils, phosphate esters, polyol esters, or PAO fluids should not be used with water glycols.

11. Preparation of Test Cartridge
11.1 Figs. 2 and 3 show the various components of the test cartridge.

11.2 Inspect all cartridge components for manufacturing or material irregularities. Use a new ring and set of vanes for each test. Reuse of the rotor and bushings is permissible if they are in satisfactory condition.

11.3 It is essential that the user is familiar with precision inspection practices, has quality instruments, and is adept in their use.

11.4 Rotor Selection and Preparation:
11.4.1 Between tests it is important to ensure that the rotor faces, journals, and slots are free of any varnish or other buildup that may inhibit free movement of the vanes.

11.4.2 If necessary, polish both faces of the rotor by holding it flat against a piece of P1200 grit paper which is supported by a glass plate or other suitable flat surface (Fig. 6). Protect the rotor journal by placing a piece of masking tape on the vertical edge of the glass or by wrapping the journal with masking tape. Push the rotor along the paper while giving the rotor one-quarter turn. Repeat until all portions of both rotor faces have been polished.

11.4.3 In some cases, it may be necessary to polish the inside surfaces of the vane slots to remove buildup, corrosion, or burrs. A piece of P1200 grit paper wrapped around a strip of steel or brass has proven satisfactory.

11.4.4 If necessary, the journals may be polished by hand with P1200 grit paper.

11.4.5 Wash the rotor with Stoddard solvent (Warning - see 7.2) and brush out the vane slots to remove any grit and oil. Air dry.

11.4.6 Ensure that clean vanes will fall freely through the vane slots.

11.4.7 Inspect used rotors for a pronounced step worn in the leading face of the rotor slot by the vanes when they are at full extension (Fig. 7). Also, check for excessive vane play in the slots. Discard rotors with these deficiencies.

11.4.8 Measure the thickness of the twelve rotor segments and record the measurements. Discard rotors when the thickness of the segments varies more than 0.005 mm.

11.5 Roll the alignment pin on a flat surface to determine if it is straight. Discard bent pins.

NOTE 16 - The amount of ring to rotor clearance, rotor to vane clearance, bushing concavity, bushing thickness, and applied head bolt torque is determined by the operator. The values given in this section are starting guidelines. In general, lower viscosity fluids require tighter clearances and flatter bushings. Experience will be the final guide for the operator.

11.6 Choose a set of components so that the average rotor thickness will be 0.017 mm to 0.035 mm less than the average ring thickness. Choose a set of vanes so that they will be 0.002 mm to 0.015 mm less than the average rotor thickness. The ring and vane dimensions have been recorded on their packaging at the factory.

11.7 Choose a pair of bushings with similar thickness and concavity. The CUP measurement listed on the bushing packaging is the amount of concavity between the outer diameter and the shank. A higher number indicates greater concavity.

11.8 Clean the cartridge parts in Stoddard solvent (Warning - see 7.2), rinse with precipitation naphtha (Warning - see 7.3) and air dry.

11.9 Use a degausser to demagnetize the ring and vanes. Determine the mass (separately) of the cam ring and the complete set of twelve vanes. Determine these two masses to the nearest milligram and record these values.

NOTE 17 - Magnetized parts can affect the performance of electronic balances.