Pneumatic fittings are the connectors that join compressed air components together — tubing to valves, cylinders to regulators, manifolds to machines. They might look simple, but get them wrong and you’ve got air leaks, pressure drops, and unscheduled downtime on your hands.
If you’re new to pneumatics or just looking to get up to speed before placing an order, this guide covers the essentials: what fittings do, the main types you’ll encounter, what they’re made from, and where they’re used across industry.
What Does a Pneumatic Fitting Actually Do?
A pneumatic fitting creates a sealed connection between two components in a compressed air system. That connection needs to hold pressure — typically anywhere from 2 to 16 bar depending on the application — without leaking, vibrating loose, or failing under repeated cycles.
In a working production environment, fittings are constantly being stressed. Temperature changes, vibration, pressure surges, and mechanical movement all put demand on every connection point. A fitting that performs reliably under those conditions isn’t a luxury — it’s a necessity.
The Main Types of Pneumatic Fittings
Push-In (Push-to-Connect) Fittings
Push-in fittings are the most common type in modern pneumatic systems. You push the tube into the fitting body and a collet grips it instantly. No tools, no thread tape, no torque wrench — just push and it’s sealed.
They’re fast to install, easy to release (press the collet ring and the tube pulls free), and available in a huge range of configurations: straight connectors, reducers, elbows, tees, crosses, and more. Parker Legris and John Guest are the two most respected names in push-in fittings, and we stock both ranges in depth.
Threaded Fittings
Threaded fittings use BSP (British Standard Pipe), NPT (National Pipe Thread), or metric threads to connect to valves, cylinders, manifolds, and other ported components. They’re used where a permanent or semi-permanent connection is needed and where the fitting screws directly into a component body. Thread sealing — using PTFE tape or anaerobic sealant — is important. An undertightened or overtightened threaded fitting is one of the most common sources of system leaks.
Elbow Fittings
Elbow fittings — available in 90° and 45° angles — allow tubing to change direction without tight bending. They’re essential in confined spaces where a straight run of tube would either kink or take up too much room. Push-in elbows in particular are invaluable during machine builds.
Tee Fittings
Tee fittings split one air supply into two, or join two lines into one. They come in equal-bore and reducing variants and are used extensively in manifold systems and wherever you need to branch a circuit.
Bulkhead Fittings
Bulkhead fittings pass tubing cleanly through a panel, enclosure wall, or cabinet. You’ll find them in control panels, machine frames, and modular equipment where tubing needs to route through a structure neatly without exposed joints.
Materials: What Are Fittings Made From?
The majority of pneumatic fittings are made from one of three materials:
- Nickel-plated brass — the standard choice for most industrial applications. Strong, corrosion-resistant, and compatible with a wide range of media.
- Stainless steel — used in food, beverage, and pharmaceutical environments where hygiene and corrosion resistance are essential.
- Composite (nylon or acetal body with brass inserts) — lightweight and cost-effective, commonly used in Parker Legris and John Guest push-in ranges for general industrial use.
Where Are Pneumatic Fittings Used?
Pneumatic fittings appear in virtually every automated production environment:
- Assembly lines and robotic systems
- Packaging and labelling machinery
- Automotive and aerospace production
- Food processing and pharmaceutical manufacturing
- Printing and converting equipment
- General workshop and maintenance air supplies
Any compressed air system — from a single machine to a full factory air network — relies on properly specified fittings to maintain pressure and flow.
Why Quality Fittings Matter
A fitting that fails costs far more than its purchase price. Unplanned downtime, wasted compressed air, and the labour cost of a fault-find and repair add up very quickly. Specifying quality fittings from established manufacturers — and replacing worn or aged connections proactively — is straightforward risk management.
Cheap fittings frequently use lower-grade seals and collet materials that degrade faster under thermal cycling and vibration. The difference between a genuine Parker Legris fitting and a generic equivalent isn’t always visible, but it shows up in service life.
Browse Pneumatic Fittings at Captivair
Captivair Pneumatics stocks one of the UK’s most comprehensive ranges of push-in and threaded pneumatic fittings, including the complete Parker Legris, John Guest, and Crouzet ranges. Whether you need a bag of straight connectors or a full set of fittings for a machine build, we can help.
Call us on 01474 334537, email sales@captivair.co.uk, or browse the fittings range online. Same-day despatch on stocked items, DPD tracked delivery throughout the UK.
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