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Pneumatics

Pneumatics covers the hardware used to generate, condition, and apply compressed air as a control and actuation medium in industrial automation. A pneumatic system typically includes air preparation equipment that filters and regulates compressed air to the required condition, cylinders and actuators that convert air pressure into mechanical motion, and the fittings and accessories that connect these components into a functioning circuit. PLC Direct stocks pneumatic hardware for replacement and maintenance in existing installed pneumatic systems.

Where Are Pneumatics Used in Industrial Environments?

Pneumatic systems are deployed wherever compressed air offers a practical advantage over electrical or hydraulic actuation, particularly in applications requiring fast cycle times, clean operation, or simple force control without the complexity of servo systems. The components in this collection support the continued operation of installed pneumatic circuits by providing replacement cylinders, air preparation units, and connection hardware.

Facilities and operations that depend on pneumatics include:

Automated assembly and production machinery using pneumatic cylinders for clamping, pressing, and part transfer operations.

Packaging and filling lines where pneumatic actuators control product flow, sealing, and carton erection functions.

Food and beverage processing facilities where pneumatic systems provide clean, oil-free actuation compatible with food safety requirements.

Woodworking, plastics, and fabrication machinery using pneumatic cylinders for material clamping and tool positioning.

Automotive manufacturing and body shop operations using pneumatic systems for welding fixtures, press operations, and part handling.

When a pneumatic component requires replacement, matching the installed product family and configuration ensures dimensional and functional compatibility with the existing circuit.

Which Brands of Pneumatics Does PLC Direct Stock?

PLC Direct stocks pneumatic hardware from Festo for replacement and maintenance in existing installed pneumatic systems.

Festo DNC and DNCI series: Standard ISO double-acting pneumatic cylinders for actuating loads in industrial automation and machine building applications.

Festo DSNU series: Round-body compact pneumatic cylinders for machine and automation applications where installation space is restricted.

Festo MS series: Modular service units including filter regulators for conditioning compressed air at the point of use in installed pneumatic circuits.

Festo pneumatic fittings and accessories: Push-in fitting connectors and connection components for pneumatic circuit assembly and maintenance in installed systems.

All pneumatic hardware in this collection is available as Sealed Surplus, Never Used Surplus, or Used/Refurbished, subject to inventory.

What Should You Know Before Ordering Pneumatics?

Hardware condition options: Pneumatic hardware is available as Sealed Surplus, Never Used Surplus, or Used/Refurbished. For cylinders and actuators, Sealed Surplus units provide known seal condition and full stroke integrity. Used/Refurbished units have been inspected, tested, and restored to working condition.

Compatibility and part identification: Pneumatic cylinders are specified by bore size, stroke length, mounting style, and connection port size, all of which are encoded in the product's part number. Air preparation units are sized for the downstream circuit's flow requirements; confirm the port connection size and installed mounting configuration when selecting a replacement FRL unit or filter regulator.

Warranty: All pneumatic hardware purchased from PLC Direct carries a standard 1-year PLC Direct warranty, not an OEM warranty, covering defects and functionality, applicable to all condition grades. This warranty is issued by PLC Direct as an independent supplier. PLC Direct supplies pneumatic hardware for replacement and maintenance purposes and does not provide system design, programming, or integration services.

Frequently Asked Questions

A single-acting cylinder uses compressed air to extend the piston and relies on an internal spring or an external load to return it to the retracted position, suitable for applications where force is required only in one direction. A double-acting cylinder uses compressed air on both sides of the piston to independently drive extension and retraction, providing controlled force and speed in both directions.

Common pneumatic cylinder mounting styles include flange mounting, foot mounting, clevis mounting, and trunnion mounting, each determining how the cylinder body and rod connect to the machine structure and how side loads are managed. The mounting style of the installed cylinder must be matched when sourcing a replacement to ensure the new unit fits the existing machine brackets and load path without requiring structural modifications.

Pneumatic cylinders use compressed air and are suited to lighter loads, faster cycle times, and cleaner operating environments where oil contamination is unacceptable. Hydraulic cylinders use pressurized fluid and can generate significantly higher forces for heavy-load applications, but require a hydraulic power unit and are more complex to seal against fluid leakage.

Seal degradation is the most common cause of premature failure, typically caused by contaminated or unlubricated compressed air, side loading on the piston rod, or operation outside the cylinder's intended load and speed range. Physical damage to the cylinder bore or rod from impact or misalignment can also cause seal failure and impaired stroke performance.

Pneumatic cylinders are controlled by solenoid-operated directional control valves that switch compressed air between the extend and retract ports, with the valve energized by a discrete output from the PLC or control system. Cylinder speed is adjusted by flow-control valves at the cylinder ports, which restrict exhaust airflow to slow piston movement in the controlled direction.