Introduction to Pneumatic Components 231

actuator

A component that directly helps convert fluid energy into mechanical energy. An actuator can be a cylinder, motor, or rotary device.

actuators

A component that directly helps convert fluid energy into mechanical energy. Actuators can be such components as cylinders, motors, or rotary devices.

adjustable cap

A part of the relief valve that controls the resistance on the pressure spring. Adjustable caps may be tightened or loosened to increase or decrease the amount of resistance against the spring.

adjusting screw

A component in a gas regulator that controls the gas flow from the cylinder into the regulator and prevents any damage to the regulator's components. Adjusting screws must be released prior to opening the cylinder valve.

aftercooler

A component that cools compressed air coming from a compressor. An aftercooler is a type of heat exchanger that also removes moisture.

air receiver

An air storage tank used with pneumatic systems. An air receiver balances air compressor capacity and airflow demand.

ambient air

Air coming from the surrounding environment. Ambient air is compressed in pneumatic systems.

ball valve

A valve that uses a spherical obstruction to stop and start pneumatic flow. A ball valve is usually rotated 90° to open and close.

blowers

A rotor inside a tube or conduit used to increase pressure and flow of a fluid. Blowers are sometimes referred to as impellers.

blow-off pressure

The point at which the internal pressure of a pneumatic system triggers a relief valve. Blow-off pressure is also called cracking pressure.

Boyle's Law

A gas law stating that the pressure and volume of a gas have an inverse relationship when temperature is constant. Boyle's Law states that if the temperature of a gas is held constant, its volume decreases as its pressure increases, and vice versa.

capacity

A pneumatic variable that indicates the volume of fluid a component can contain. Capacity is also used occasionally to indicate flow rate.

Charles' Law

A gas law stating that the volume of a gas has a direct relationship with temperature when pressure is constant. Charles' Law states that when a gas's pressure is constant, its volume and temperature increase at the same rate.

check valves

A pneumatic control valve that ensures fluids flow in one direction. Check valves prevent backflow.

compressibility

The ability to be condensed by pressure. Gases have high compressibility, while liquids do not.

compressor

A component that pressurizes ambient air and directs it into a pneumatic system. Compressors are powered by prime movers.

compressor

A component that pressurizes ambient air. Compressors also direct air in a pneumatic system.

conductors

The components that convey fluids throughout a hydraulic or pneumatic system. Conductors are pipes, tubes, and hoses.

control valves

A component that controls the flow of pneumatic gases. Control valves include on-and-off valves and directional control valves.

corrosion

The gradual chemical attack on a material. Corrosion may be caused by atmosphere, moisture, or other agents.

cracking pressure

The point at which the internal pressure of a pneumatic system triggers a relief valve. Cracking pressure is also called blow-off pressure.

crank

A rod that spins and drives a piston in a piston compressor. The crank is powered by a motor.

cubic feet per minute

cfm. A measurement of airflow that indicates how many feet of air pass by a stationary point in one minute. The metric equivalent is cubic meters per minute.

cylinder

A type of linear actuator that uses a piston to produce motion in a straight line. A cylinder is also known as a piston actuator.

density

The relative "compactness" of a material. Density is the mass of a material per unit volume.

diaphragm

A spring-loaded valve mechanism that moves in response to variations in pressure in a pneumatic system. The diaphragm is a flexible membrane that responds to changes in pressure and moves the poppet.

direct relationship

An association in which the values of multiple variables increase or decrease at the same rate. A direct relationship is also called a positive relationship.

dithering

The continuous opening and closing movement of a poppet in a pressure regulating valve. Dithering happens in response to pressure in a pneumatic system.

double-acting cylinder

A pneumatic actuator that directs energy in two directions. A double-acting cylinder has a port at each end, supplied with hydraulic fluid for both the retraction and extension of the piston.

electric motor

A machine that converts electricity into mechanical energy or motion. An electric motor is a type of prime mover for a pneumatic system.

expandability

A measure of a substance’s tendency to expand. Substances with high expandability, such as gases, tend to expand until they fill their container.

filter regulator lubricator

A device that conditions air for use in pneumatic systems. A filter-regulator-lubricator is commonly called an FRL unit.

flow rate

A specification of a compressor that indicates how much air a compressor can move in a certain amount of time. Flow rate for pneumatic pumps is measured in cubic feet per minute (cfm).

fluid power

Power derived from the motion and pressure of a fluid, such as water, oil, or air. Fluid power sources include hydraulics and pneumatics.

force

An influence, such as a push or a pull, which produces a change in an object's motion or state of rest. Force has a specific direction and magnitude.

force multiplication

An exponential increase in available power created by tools or power transmission systems. Hydraulic and pneumatic drives provide high force multiplication.

friction

A force that resists motion between two objects that are in contact with each other. Friction is a type of contact force used in mechanical systems.

FRL

A device that conditions air for use in pneumatic systems. A filter-regulator-lubricator is commonly called an FRL.

Gay-Lussac's Law

A gas law stating that the temperature of a gas has a direct relationship with pressure when volume is constant. Gay-Lussac's Law states that when a gas's volume is constant, its pressure and temperature increase at the same rate.

globe valve

A valve that adjusts the flow of pneumatic fluid between and including fully on and fully off. The globe valve consists of a circular plug and a tapered seat.

grippers

A double-acting linear actuator. Grippers have the capability to repeatedly clamp and release.

hosing

A type of pneumatic fluid conductor that joins other components, usually in nonlinear fashion. Hosing bends and flexes and is the most versatile pneumatic conductor.

impellers

A rotor inside a tube or conduit used to increase pressure and flow of a fluid. Impellers are sometimes referred to as blowers.

inlet valve

A one-way valve that lets air into a compressor. Inlet valves start the process of moving fluid through the pneumatic system.

intake

A device that brings gases into a pneumatic system. Intake devices often bring in ambient air to power the system.

inverse relationship

An association in which the value of one variable increases while the value of the other decreases, and vice versa. An inverse relationship is also called a negative relationship.

laws

A set of recognized rules that do not waiver under certain conditions.

linear actuator

An actuator that directs force in a straight line. A cylinder is a linear actuator.

linear motion

Movement along a straight line. Linear motion, which is also called rectilinear motion, is one of two basic forms of motion that mechanical energy can take.

lobed-rotor compressors

A pneumatic compressor that derives its pressurizing ability from two interlocking gear-type rotors. Lobed-rotor compressors provide high efficiency and reliability.

lobes

The portions of a lobed-rotor pneumatic compressor's impeller that interlock and provide the ability to compress air. Lobes do not make contact in the compressor.

lubrication

The use of a slippery substance, such as oil or graphite, between two moving surfaces that are in contact with each other. Lubrication minimizes friction, which aids movement and reduces heat.

lubricator

A component that releases an oil mist into certain portions of a pneumatic system to lubricate moving parts. A lubricator is a component of an FRL unit.

mechanical energy

A form of power used to perform work. Mechanical energy occurs due to the physical interaction and motion of instruments or tools.

mechanical energy

Energy used to perform work. Mechanical energy operates through the physical interaction and motion of instruments or tools.

mechanical power

Energy created by the physical interaction and motion of instruments or tools. Mechanical power is transmitted through a mechanical system and used to perform work.

muffler

A pneumatic component that decreases harmful noise. A muffler slows air as it is exhausted from a pneumatic system.

needle valve

A valve that adjusts the flow of pneumatic fluid between and including fully on and fully off. The needle valve consists of a sharp conical obstruction that mates with a sharp conical depression.

oil

A slippery fluid commonly used as a lubricant. Both natural and synthetic oils are used in industrial applications.

oil scrubber

A component that removes oil from certain areas of a pneumatic system. Oil scrubbers prevent valve clogging and seal failure.

o-rings

A flexible, rubberlike ring that is used to create a mechanical seal. O-rings are usually located in a groove and compressed between two or more fitting components.

outlet valve

A one-way valve that lets air out of a compressor. The outlet valve completes the pneumatic system.

piping

A type of pneumatic fluid conductor. Piping joins other components, usually in a straight line and on a permanent basis.

piston

A cylindrical component that moves up and down inside a hollow cylinder in response to a pressure change in pneumatic and hydraulic systems. Pistons may be used to transfer motion.

piston

A rod inside a cylinder that is moved by pneumatic pressure. A piston is contained by a cylinder.

piston compressors

A compressor that uses a piston driven by a rotating crankshaft to pressurize air in a pneumatic system. Piston compressors are also known as reciprocating compressors.

plug valve

A cylindrical, tapered valve that is raised or lowered within a seat. Plugs maintain, restrict, or completely shut off flow.

pneumatic energy

A form of power used to perform work. Pneumatic energy occurs due to the compressive force of air in a confined area.

pneumatic motor

A device that converts the energy from gas flow into mechanical motion. A pneumatic motor is a type of fluid motor that is cable of continuous motion.

pneumatic power

Power caused by the motion and control of gas, such as air, under pressure. Pneumatic power systems convert energy from pressurized gas into mechanical motion.

poppet

A valve mechanism that continually opens and closes in response to variations in pressure. The poppet is attached to a spring-loaded diaphragm.

poppet valves

A pneumatic control valve that redirects the flow of gas when actuated. Poppet valves consist of a hole, usually round or oval, and a tapered plug.

port

An opening on a valve through which fluid can flow. A port allows air into and out of a pneumatic system.

power

The rate at which work is accomplished. Power is the result of the amount of work accomplished divided by the time it took to do the work.

press brakes

A type of press with an open frame and wide, narrow bed. Press brakes are often used for bending operations, and they are typically manually operated.

pressure

The exertion of force upon a substance. Pressure can cause changes to the properties of a gas.

pressure regulating valve

A component that monitors gas passageways in a pneumatic system. A pressure regulating valve maintains a consistent pressure level in the system.

pressure regulating valves

A component that monitors gas passageways in a pneumatic system. Pressure regulating valves maintain a consistent pressure level in a pneumatic system.

pressure spring

A flexible device used to apply force, control motion and vibration, and store energy. A spring yields under a compressive force and returns to its original shape once the force is removed.

pressure switch

A mechanism that regulates pressure in an air receiver. Pressure switches are actuated by a change in pressure.

prime mover

The component of a hydraulic or pneumatic system that powers the main pump or compressor. Common prime movers for hydraulic systems include electric or diesel-powered motors.

rack-and-pinion actuator

A pneumatic rotary actuator that directs energy in a circular motion. Rack-and-Pinion actuators use a toothed piston that moves linearly and turns a toothed gear.

reciprocating compressors

A compressor that uses a piston driven by a rotating crankshaft to pressurize air in a pneumatic system. Reciprocating compressors are also known as piston compressors.

reciprocating motions

Having a repeated back-and-forth movement.

relief valve

A control valve that regulates pressure in a fluid system. When a critical pressure is exceeded, the relief valve releases.

relief valves

A component that allows pressurized gas to escape a pneumatic system when the pressure of the system reaches a critical point. Relief valves keep damage from occuring.

resistance

The opposition to a force, such as the weight of a load or friction to movement.

revolutions per minute

rpm. The number of times a component rotates in a complete circle, in one minute. Revolutions per minute is a measurement of speed.

robotics

A field of science that is focused on programmable mechanical devices. Robotics enables a person to do work with a higher degree of accuracy.

rotary actuator

An actuator that directs force in a circular motion. Rotary actuators are limited rotation devices.

rotary compressors

A pneumatic compressor that derives its pressurizing ability from a spinning component. Rotary compressors work in cycles.

rotary screw compressors

A pneumatic compressor that derives its pressurizing ability from two interlocking threaded cylinders. In a rotary screw compressor, the thread interaction traps and compresses air.

rotary valves

A pneumatic control valve that redirects the flow of gas when turned. Rotary valves rotate continuously in an arc.

rotor

The main spinning portion of a rotary compressor. Rotors perform work by directing force in a circular motion.

schedule 40

The most common pipe designation that indicates the thickness of pipe wall and how much pressure a pipe can withstand. Other schedules include 80, 10, and 5.

separator

A component that removes water from cooled air. A separator keeps water from accumulating and damaging the pneumatic system.

separator

A component that removes water from cooled air. Separators keep water from accumulating and damaging the pneumatic system.

single-acting cylinder

A pneumatic actuator that directs energy in one direction. In a single-acting cylinder the working fluid acts on one side of the piston only.

solenoids

A coil of wire that generates an electromagnetic force when a current is applied. When activated, solenoids can open and close valves.

spool valves

A valve that controls the direction of pneumatic flow. A spool valve consists of cylindrical spools that alternately block and open channels in a pneumatic system.

spring

An elastic device used to dampen and apply force, control motion and vibration, and store energy. Springs are used in many mechanical systems to aid in the storage and transfer of energy.

temperature

A measurement of thermal energy or heat in a substance. Molecular activity determines temperature.

tubing

A type of pneumatic fluid conductor that joins other components, usually in nonlinear fashion. Tubing is easily bent.

vane actuator

A pneumatic rotary actuator that directs energy in a circular motion. Vane actuators use a pivoting mechanism to direct fluid.

vane compressors

A pneumatic compressor that consists of a rotor mounted off-center in a circular cavity. As the rotor spins, vanes trap and compress air.

vanes

A retractable spring-loaded mechanism that extends radially from the center of a rotor pump. Vanes trap and move fluid to an outlet port.

variable

A changing value, or an unknown value.

volume

The amount of space that a material or substance occupies. In pneumatic systems, volume describes both the quantity of fluid and the capacity of a component.

wear

The erosion of material as a result of friction. Wear typically is caused by two or more objects rubbing or sliding against each other.

work

The result of a force applied to an object and the distance through which the force is applied. Work is force multiplied by distance.

workholding devices

A device used to support, locate, and hold a workpiece during machining. Workholding devices include clamps, vices, and collets.