Valve & Pneumatics Glossary
Plain-language definitions of the valve automation and pneumatics terms used across our product range - actuators, solenoid valves, ISO 5211, Namur and more.
Read guide3/2 vs 5/2 Solenoid Valve - What's the Difference?
A 3/2 valve has 3 ports and 2 positions, used for single-acting actuators. A 5/2 valve has 5 ports and 2 positions, used for double-acting actuators. Here's how to choose.
Read guideDouble Acting vs Spring Return Actuator
Double-acting actuators use air for both open and close strokes and hold position on air loss. Spring-return actuators fail to a defined safe position. Here's how to decide.
Read guideBall Valve vs Butterfly Valve
Ball valves offer tighter shut-off and full-port flow; butterfly valves are lighter and more compact for larger bores. Here's how to decide between them.
Read guideHow to Size a Pneumatic Actuator
The four things that determine actuator sizing: valve torque requirement, available air pressure, fail-safe requirement and duty cycle. A practical walkthrough.
Read guideDatasheet Library
Downloadable datasheets for Duncan (formerly Schrader Duncan) pneumatics - air cylinders, solenoid and directional control valves, FRL units, positioners and accessories.
Read guidePneumatic vs Electric Actuator
Pneumatic actuators are faster, simpler and inherently fail-safe wherever compressed air already exists. Electric actuators run without an air supply and hold precise position. Here's how to decide.
Read guideGenuine vs Equivalent Spares
A genuine spare is made by the original brand. An equivalent is a matched substitute from a different ISO 9001 certified manufacturer, used when the original is discontinued or lead time doesn't fit. Here's when each applies.
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