Hydraulics and Pneumatics Training


Class Information
Tooling U classes are offered at the beginner, intermediate, and advanced levels. The typical class consists of 12 to 25 lessons and will take approximately one hour to complete.
Class Name:Hydraulic Control Valves 230
Description:This class surveys the most common types of hydraulic control valves and explains how each type functions within a hydraulic system. Includes an Interactive Lab.
Prerequisites: 570100  570120 
Difficulty:Intermediate
Number of Lessons:17
Language:English, Spanish

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Below are all the competencies and job programs that contain the class Hydraulic Control Valves 230. Job programs are our traditional class lists organized according to common job functions. Competencies are our latest job-specific curricula that help tie online learning to practical, hands-on tasks.

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Competencies


Class Outline
  • Objectives
  • Hydraulic Control
  • Types of Hydraulic Valves
  • Directional Control Valves
  • Check Valves
  • Pilot-Operated Check Valves
  • Two-, Three-, and Four-Way Valves
  • Directional Control Valve Actuation
  • Relief Valves
  • Balanced Piston Relief Valve
  • Sequence Valve
  • Pressure Reducing Valves
  • Flow Control Valves
  • Nonpressure-Compensated Flow Control
  • Pressure-Compensated Flow Control
  • Temperature-Compensated Flow Control
  • Summary
  
Class Objectives
  • Describe hydraulic valves.
  • Identify the types of hydraulic valves.
  • Describe directional control valves.
  • Describe check valves.
  • Describe a pilot-operated check valve.
  • Distinguish between two-, three-, and four-way valves.
  • Distinguish between methods of directional valve actuation.
  • Distinguish between types of relief valves.
  • Describe pilot-operated relief valves.
  • Describe a pilot-operated sequence valve.
  • Describe a pressure reducing valve.
  • Describe the different flow control configurations.
  • Describe nonpressure-compensated flow control valves.
  • Describe pressure-compensated flow control valves.
  • Describe a temperature-compensated flow control valve.

Class Vocabulary

Vocabulary TermDefinition
2/2 valve A directional control valve with two ways, two ports, and two positions.
3/2 valve A directional control valve with three ways, three ports, and two positions.
4/2 valve A directional control valve with four ways, four ports, and two positions.
4/3 valve A directional control valve with four ways, four ports, and three positions.
actuation The act of performing a valve function. Actuation is the point at which a valve is triggered.
air-piloted directional control valve A directional control valve that is actuated by compressed air coming from the pilot port.
balanced piston The lower valve portion of a pilot-operated relief valve. During normal operation, the piston is balanced between system pressure and a light spring.
balanced piston relief valve A pilot-operated relief valve consisting of two valve components in a common housing. The adjustable relief, or pilot, portion is located above and consists of a spring-tensioned poppet. The outlet ports are located below and are monitored by a spring-tensioned balanced piston.
bleed-off circuit A flow control configuration in which a valve directs flow back to the tank when actuated. The valve of the bleed-off circuit can be located anywhere along the main line.
cam-operated directional control valve A directional control valve that is actuated by the distinct physical geometry of a cam. As the cam rotates, its shape actuates the valving mechanism of the valve.
check valve A control valve that allows fluid to flow in only one direction. Check valves prevent backflow.
cracking pressure The point at which the internal pressure of a hydraulic system triggers or actuates a valve. Also called the blow-off pressure.
differential pressure The difference between two levels of pressure. During operation, valves often experience different pressure levels downstream and upstream.
directional control valve A fluid component that determines the path liquid takes in a hydraulic system.
direct-operated Actuated by hydraulic fluid pressing directly on the valving element.
downstream In a direction away from the source of power in a fluid system. Downstream in a hydraulic system is in the same direction as the fluid is moving.
electrical actuation The act of tripping or seating a valving element with an electrical device such as a solenoid.
finite positioning The quality of a component characterized by opening and closing at a small number of fixed positions.
flow control valve A fluid component that controls the rate of fluid flow. Flow control valves make it possible to control other system variables like the speed of an actuator.
four-way valve A directional control valve typically used for double-acting actuators.
full-flow pressure The point at which a relief valve is diverting flow at its maximum rate.
gripper A double-acting liner actuator that has the capability to repeatedly clamp and release.
hydraulic actuation The act of tripping or seating a valving element with pressurized liquid.
infinite positioning Characterized by being fully on, fully off, or anywhere in between. Infinite positioning allows any range of possible positions.
in-line check valve A check valve with the inlet and outlet located directly opposite each other.
limit switch A device used for making, breaking, or for changing the connections in an electric circuit.
lunging A situation in which the actuator and the load are moving in the same direction. Lunging, or overrunning, often causes the actuator to jump.
manual actuation The act of tripping or seating a valving element by hand.
mechanical actuation The act of tripping or seating a valving element through the intervention of a mechanical device such as a plunger or cylinder.
meter-in circuit A flow control configuration in which the valve is located between the pump and the actuator.
meter-out circuit A flow control configuration in which the valve is located at the outlet of the actuator.
needle valve A valve that adjusts the flow of fluid between and including fully on and fully off. The needle valve consists of a sharp conical obstruction that is extended or retracted to block or allow flow.
nonpressure-compensated valve A flow control valve used in situations in which the load on the actuator is stable. Nonpressure-compensated valves do not adjust to changes in pressure or temperature.
normally closed position A valve position in which the valving element is unactuated and covering a port. A normally closed valve opens when it actuates.
normally open A valve position in which the valving element is unactuated and not covering a port. A normally open valve closes when it actuates.
overpressure A situation in which the pressure in a hydraulic system has exceeded recommended levels. Overpressure can lead to equipment damage and personal injury.
override A means of bypassing the essential function of a device, such as a valve. Overrides exist for various exceptions that can occur during normal operation.
pilot port The port through which fluid travels when actuating the pilot portion of a pilot operated valve.
pilot signal The actual surge of fluid through the pilot port that actuates the pilot portion of a pilot operated valve.
pilot-operated Actuated by hydraulic fluid coming from a pilot or ancillary port for the purpose of overriding a valve.
pilot-operated check valve A check valve that is direct-operated under normal circumstances and actuated by a pilot signal under circumstances that call for a valve override.
pilot-operated pressure reducing valve A normally open pressure control valve that sustains a particular pressure level in a hydraulic system. The pilot portion allows more flow control and accuracy and diverts flow directly to the reservoir when target pressure is reached.
pilot-operated relief valve A pressure relief valve with two valve components in a common housing. The pilot-operated relief valve has a small pressure override, which means it takes less energy to crack the valve.
pilot-operated sequence valve A pressure control valve that discharges fluid directly from the body of the valve to the reservoir. This valve is similar in appearance to the pilot-operated relief valve.
pilot-to-close check valve A check valve that allows flow in the forward direction and stops flow in the reverse direction under normal circumstances. The pilot port stops flow in either direction by closing the poppet when needed.
pilot-to-open check valve A check valve that allows flow in the forward direction and stops flow in the reverse under normal circumstances. The pilot port allows flow in the reverse direction by opening the poppet when needed.
PLC A processor driven device that uses logic-based software to provide electrical control to machines.
plunger A cylindrical device used in valves to actuate the valving element.
pneumatic actuation The act of tripping or seating a valving element with compressed air.
poppet A conical valving element that continually opens and closes in response to variations in pressure.
port An opening on a valve through which fluid can flow.
position The number of physical settings on a directional control valve. A three-position valve can be placed in three different physical settings with a control such as a lever.
pressure control valve A fluid component that monitors pressure in a hydraulic system. Pressure control valves protect a hydraulic system from damage due to overpressure.
pressure drop The pressure from a load on an actuator minus the cracking pressure of a valve. Pressure drop is also called pressure differential and represents the difference between two pressure levels.
pressure override The full-flow pressure minus the cracking pressure. The pressure override is a measure of the increase in pressure over the cracking pressure when additional flow passes through the valve after it cracks.
pressure port A valve inlet port closest to the pump.
pressure reducing valve A normally open pressure control valve that sustains a particular pressure level in a hydraulic system.
pressure-compensated valve A flow control valve that automatically adjusts the size of its orifice in response to changes in pressure. Pressure-compensated valves seek to maintain constant flow depite changes in pressure.
relief valve A component that allows pressurized liquid to drain back to the reservoir once a hydraulic system reaches a critical pressure, beyond which damage or injury can occur.
restriction check valve A directional control valve that allows fluid to flow freely in one direction, and allows a small amount of fluid to pass in the other direction, the normally closed position.
restriction valve A check valve with the inlet and outlet located at right angles of each other and monitored by a poppet with a drilled orifice.
right angle check valve A check valve with the inlet and outlet located at right angles of each other.
rotary valve A directional control valve that directs the flow of fluid when turned.
sequence valve A pressure control valve that allows hydraulic fluid to flow into a secondary system after a critical pressure is reached.
sharp edge orifice A temperature compensated valve mechanism consisting of a thin plate with a small, clean hole drilled through. The sharp edge orifice restricts flow regardless of fluid viscosity, which means fluids of varying temperature and viscosity is restricted in the same manner.
solenoid A coil of wire that generates an electromagnetic force when a current is applied. When activated, solenoids can open and close valves.
spool A cylindrical valving element that alternately allows and blocks flow depending on its linear position.
swing check valve An in-line, one way directional control valve with a pivoting valve mechanism. The swing opens and closes like a door and allows fluid flow in one direction only.
tank port A valve outlet port that leads to the reservoir.
temperature-compensated valve A flow control valve that automatically adjusts the size of its orifice in response to changes in temperature. Temperature-compensated valves seek to maintain constant flow depite changes in temperature.
three-way valve A directional control valve that diverts flow between two possible paths. Three-way valves allow flow from the pressure port to two other ports.
two-way valve A valve with one inlet pressure port that services one of two possible outlets, depending on the position of the valve.
unloading relief valve A pressure relief valve consisting of a relief valve, a check valve, and a plunger. The unloading relief valve is typically located near a pump to "unload" it when a critical pressure downstream has been reached.
upstream In a direction toward the source of power in a fluid system. Upstream in a hydraulic system is in the direction from which the fluid is coming.
valve A mechanical device that regulates the flow of liquid in a hydraulic system. Valves are responsible primarily for the proper control of the hydraulic system.
valving element The component of a valve that covers a port. Depending on the design of the valve, the valving element controls direction, pressure, and flow by opening and closing.
viscosity A hydraulic fluid's resistance to flow. As temperature increases, viscosity decreases.
way A characteristic of a valve that indicates how a fluid can flow through it.