Pneumatics

Most pneumatic ordering errors are thread-standard or size errors, and they are easy to avoid if you check five things.

Thread standard first

Port threads look alike and are not interchangeable. NPT and BSPT are tapered and seal on the thread, while BSPP (G) is parallel and seals on a washer or O-ring. A 1/4 inch NPT fitting will not seal in a 1/4 inch G port. Identify the thread before you choose a valve, cylinder or fitting.

Cylinders

A cylinder is defined by bore, stroke, mounting style, rod end and cushioning, plus a magnetic piston if you use position switches. Cylinders built to ISO 15552 share standard mounting dimensions across brands, which makes like-for-like replacement much easier than with proprietary designs.

Valves, tubing and air preparation

Describe a valve by its function (for example 5/2 single or double solenoid), port size and coil voltage; 24 V DC and 120 V AC are common. Tubing and push-in fittings must match the tube outside diameter, and metric and inch sizes are not interchangeable. Filter-regulator-lubricator units are sized by port size and flow, not only by thread.

What to have ready

• Bore and stroke, and the mounting style (foot, flange, clevis)
• Port thread (NPT, BSPP or BSPT) and size
• Valve function (such as 5/2 or 5/3), coil voltage and connector
• Tube outside diameter, metric or inch
• Operating pressure, and the brand and series of the part being replaced

Related guides and tools

• Tool: Cylinder Force Calculator
• Guide: Pneumatic Fitting Thread Guide
• Tool: Thread Identifier

Not sure which one you have? Send us the number, a nameplate photo or the dimensions and the order desk replies within 1 business day.