Hydraulic Systems 2 part 2

A pilot-operated check valve is used instead of a DCV with a closed spool to hold a cylinder because _____.

• A. They are cheaper

• B. The check valve requires less maintenance

• C. The DCV's spool leaks

• D. The DCV spool sticks at high pressures

The most basic load-lock circuit uses a single _____ in one of the cylinder lines to resist the movement of the cylinder by the load.

• A. Needle valve

• B. Flow control valve

• C. DCV

• D. POC

_____ pilot-operated check valves is/are used in load-lock circuits when forces act in both directions on a cylinder or forces act to retract on a cylinder.

• A. One

• B. Two

• C. Three

• D. Four

A double POC valve has two pilot-operated check valves built into one housing and requires _____ lines to be connected

• A. One

• B. Two

• C. Three

• D. Four

A _____ valve is used to fill large volume cylinders as they extend by gravity or suction instead of suing large volume pumps.

• A. Directional control

• B. Ball

• C. Needle

• D. Prefill

The piston area of a pilot-operated check valve is alwasy larger than the _____.

• A. Poppet area

• B. Port area

• C. Spring rate

• D, Poppet circumference

In order to calculate the Pilot Pressure with no pressure supplied to the cylinder requires which of the following parameters?

• A. Load pressure

• B. Pilot Ratio

• C. Spring and friction of the check valve

• D. Size of the POC valve

• E. A, B, and C above

_____ is the increase in pressure in a part of the circuit above the system pressure at the pump outlet/

• A. Pressure spike

• B. In-rush pressure

• C. Pressure intensification

• D. Fluid hammer

The maximum pressure that will occur in a POC circuit when piloting from opposite cylinder is determined by _____, load pressure, and pilot pressure.

• A. Spring ratio

• B. In-rush pressure

• C. Cylinder area ratio

• D. High pressure

A decompression poppet is used in a pilot-operated check valve to eliminate _____.

• A. Low pressure

• B. High pressure

• C. Hydraulic shock

• D. Hydraulic leakage