PUMPS & PUMPING PRINCIPLES EXAM MM 2 3 INCH 10 5 9 10 11 12 13 14 15 STAINLESS STEEL 31 4 5 6 MECT-1320 Revised 5/05/15 Page 1 of 3 PS. 2. Piston type pumps that are equipped with pressure compensator controls have which ONE of the following characteristics: 1. A. (B. C. 423 D. They usually generate more heat in a system. It changes its displacement when the compensator setting is reached. They never require a relief valve for over-pressure protection. They can automatically change flow direction to meet system needs. Vane pump output flow can be affected by changing the: A. Force of the springs under the vanes. Velocity of the resistive load. B. C. Width of the cam ring, rotor, and vanes, D. Dow PS. 417 Fluid reservoir blanket pressure. Vane pump minimum starting speed of 600 RPM is recommended: To avoid low-speed cavitation. A. B. C. D.- To minimize aeration and gas entrainment. To improve lubrication of rotating parts.. To bring the vanes in contact with the cam ring. Piston type pumps: 4. A. B. C. D. - Do not require an external case drain. Utilize centripetal force to produce pressure. Cannot be used in high pressure applications. Have a high volumetric efficiency. Variable-displacement vane pumps vary their displacement by: Positioning the cam ring. 5. A. B. Limiting vane movement. C. Moving the rotor. D. Varying intra-vane pressure. 6. The external drain line used with piston pumps: A. Should be terminated below the reservoir low oil level B. Should create a back pressure of at least 25 PSI. C. D. Should be terminated above the reservoir fluid level. Should have an anti-siphon vent hole in it.