ASTM D7109 Standard Test Method for Shear Stability of Polymer Containing Fluids Using a European Diesel Injector Apparatus at 30 and 90 Cycles
6. Apparatus
6.1 The apparatus consists of a fluid reservoir, a double-plunger pump with an electric motor drive, an atomization chamber with a diesel injector spray nozzle, and a fluid cooling vessel, installed in an area with an ambient temperature of 20 to 25°C (68 to 77°F). Fig. 1 shows the schematic representation of equipment.
6.1.1 Fluid Reservoir - In Fig. 1, the fluid reservoir (7) is open on the top, has approximately a 250 mL capacity, has a 45-mm (1.772-in.) inner diameter, and is calibrated in units of volume. It is fitted with an internal fluid distributor as detailed in Fig. 2. A 40-mm (1.575-in.) diameter watch glass with serrated edges is an acceptable distributor plate. The distributor reduces the tendency of fluid channeling. Temperature is measured by a thermometer suspended in the center of the fluid reservoir. The bottom of the thermometer bulb shall be 10 to 15 mm above the entrance to the drain tube opening. Other temperature-measuring equipment positioned at the same location may also be used. The outlet is equipped with a three-way stopcock (8). The three-way stopcock is of a cone type with a nonexchangeable solid plug with an 8-mm (0.315-in.) nominal bore size. Transparent plastic tubing, (10) in Fig. 1, is used to connect the three-way stopcock to the pump inlet.
6.1.2 Double-Plunger Injection Pump - In Fig. 1, the injection pump (11) is defined as Bosch PE 2 A 90D 300/3 S2266. This pump is equipped with a stroke counter (15), venting screw (14), and a flow rate adjusting screw (12).
6.1.3 Injection Pump, driven by a three-phase electric motor (13) in Fig. 1, rated at a speed of 925 +/- 25 rpm.
6.1.3.1 This motor runs at 925 rpm on the 50 Hz current prevalent in Europe; it will run at approximately 1100 rpm on 60 Hz current. The 1100 rpm speed is not acceptable in this procedure. A suitable means shall be taken to ensure the prescribed 925 +/- 25 rpm speed to the injection pump. One acceptable method is to use a 6 to 5 speed reducer.
6.1.4 Outlet of Injection Pump, connected to the atomization chamber using high pressure steel tubing. The atomization chamber (2) in Fig. 1, is defined in more detail in Fig. 3. To minimize foam generation, the spray chamber is designed so that the fluid under test exits from the nozzle into a chamber filled with the test fluid. A drain tube (17) fitted with a two-way stopcock is included to minimize contamination from the previous test during the system cleaning steps. The diesel injector nozzle is a Bosch DN 8 S 2-type pintle nozzle injector, number 0434 200 012, installed in a Bosch KD 43 SA 53/15 nozzle holder. The nozzle holder includes a filter cartridge.
NOTE 8 - Exercise great care to avoid damage to the precision parts of the fuel injection equipment (the plunger and barrel in the pump and the nozzle valve assembly). Service work on the equipment should be performed by a diesel fuel injector pump specialist or with reference to the manufacturer's service manual.
NOTE 9 - An unusually rapid rise in gauge pressure during testing may signify filter blockage. When this occurs, the filter cartridge shall be replaced.
6.1.5 Pressure Sensing Device (18), such as a glycerol-filled pressure gauge or electronic, digital display pressure indicator, shall be installed and separated from the line by a pressure snubber or needle valve to suitably dampen pressure surges. The pressure device shall be occasionally pressure tested to ensure accuracy.
6.1.6 Fluid Cooling Vessel, ((5) in Fig. 1), used to maintain the specified temperature of the test fluid, as indicated at the outlet of the fluid reservoir. This vessel is a glass container with exterior cooling jacket constructed so that the heat transfer surface of the jacket is spherical. The exterior jacket diameter, d1, is approximately 50 mm (1.969 in.). The interior heat transfer surface, d2, is approximately 25 mm (0.984 in.) in diameter. The overall length, L, is approximately 180 mm (7.087 in.). A distributor plate, similar in design to the distributor plate in the fluid reservoir, is positioned in the upper portion of the fluid cooling vessel to ensure contact between the fluid and the cooling surface. The discharge from the fluid cooling vessel is through a three-way stopcock of the same design used on the discharge of the fluid reservoir. The exterior cooling jacket shall be supplied with an adjustable volume of cold water.
7. Materials
7.1 Diesel Fuel (No. 2), initially required to adjust the diesel injector nozzle valve opening pressure.
7.2 Calibration Fluid, used to ensure that when the apparatus is adjusted within a prescribed pressure range, the correct viscosity loss is obtained.
7.3 Calibration Fluid RL233, used to ensure that when the apparatus is adjusted within a prescribed pressure range, the correct viscosity loss is obtained.
NOTE 10 - RL233 meets the requirements of this test method and is acceptable during a transition period between suppliers. See research report for details of the equivalence testing.
8. Hazards
8.1 (Warning - Use a safety shield between the high-pressure components and the operator during use of equipment.)
8.2 (Warning - During operation, the line between the pump and nozzle, ((16) in Fig. 1), is under a pressure of at least 13.0 MPa (130 bar or 1885 psi). Pressures above the upper limit of 18.0 MPa (180 bar or 2611 psi) are possible if filter plugging occurs. Shut off the pump prior to tightening any fitting that is not properly sealed.)
