4.6.2.1 Volumetric efficiency. To determine conformance to 3.3.3 and 3.4.1, the pump
shall be connected to a double-acting cylinder with a piston area at each end of 2.75 square inches
(in.2) (17.7 square centimeters (cm2)). A needle valve and a 2000 psi (13 788 kPa) gage shall be
installed to each line from the pump to the cylinder. A pressure gage shall be installed between
the needle valve and the pump port. The system shall be charged to a pressure of 1500 psi
(10 342 kPa) with needle valve on the discharge side of the cylinder set to give a differential of
100 psi (689 kPa) between the ports of the pump. The control handle shall be rotated at a speed
of one revolution per minute (rpm). Distance traveled by piston rod of cylinder shall be measured
in one revolution of control handle by a dial indicator. This test shall be made once in a clockwise
direction and once in a counterclockwise direction of rotation.