Hyd Ch 10

Front 1

control valves allow a hydraulic system to produce the type of __ and level of __ needed for machine operation

Back 1

motion, force

Front 2

controlling the flow rate of fluid entering an actuator controls the __ of that actuator

Back 2

speed

Front 3

the __ serves as the holder of all the working elements of the valve

Back 3

valve body

Front 4

list the three sources of external force that can be used to position control valve elements

Back 4

electromagnetics, pilot, mechanical

Front 5

what are the two sources of internal force typically used to postion control valve elements

Back 5

spring, pilot

Front 6

heavy internal springs are used to establish the operating pressure of the __ operated type of pressure control valve

Back 6

direct

Front 7

describe a hydraulic pressure fuse

Back 7

a disk that bursts when the maximum pressure is exceeded

Front 8

name two basic uses of springs in the operation of hydraulic control balves

Back 8

maximum operating pressure, returning device to its original position

Front 9

name the two types of pressure control valves that are used to prevent damage to hydraulic systems in cases where the system relief valve fails, causing excessive system pressure

Back 9

hydraulic pressure fuse, shut off valve

Front 10

counterbalance and brake valves provide __ control in hydraulic systems

Back 10

restrained movement

Front 11

safety valves are typically set at a pressure __% above the setting of the primary system relief valve

Back 11

25

Front 12

an unloading relief valve uses a __ mechanism to assist in the operation of the balancing piston in the pilot section of the valve

Back 12

plunger

Front 13

what are the four general classifications of directional control valves used in a hydraulic system

Back 13

shut off, check, 3way, 4way

Front 14

a pressure reducing valve is normally open and must be __ drained

Back 14

externally

Front 15

__ valves are used in hydraulic systems as both shut off and metering devices

Back 15

needle

Front 16

__ valves may be adjusted from the fully open position to the fully closed position by turning the control handle only 90 degrees

Back 16

ball

Front 17

__ directional control valves are designed for the actuation of rams and single acting cylinders

Back 17

3way

Front 18

a three way directional control valve has 3 ports. name what each port is connected to in the system

Back 18

pump discharge, cylinder inlet, reservoir inlet

Front 19

which type of four way valve allows cylinder extension in one position and cylinder retraction in the 2nd postion

Back 19

2 postition

Front 20

the middle position in a three position four way directional control valve is often called the __ position. it provides a control feature beyond cylinder extension and retraction

Back 20

center

Front 21

what are four general categories of actuation methods used to shift directional control valves

Back 21

mechanical

electrical

pilot

manual

Front 22

the __ method of directional control activation uses system pressure which may be remotely sensed, to shift the valve

Back 22

pilot

Front 23

__ are often used on the ends of the spool in directional control valves to automatically return the valve to the normal or restart position whenever the activation force is removed

Back 23

springs

Front 24

what are the 2 general operating designs of flow control valves

Back 24

restricting

bypass

Front 25

the __ is the simplest of the adjustable, noncompensated flow control valves

Back 25

needle