John Guest is the original and market-leading manufacturer of push-fit tube fittings. Founded in the UK in the 1960s, John Guest invented the push-in fitting concept and has refined it over decades into a comprehensive range trusted in industries from food and beverage to pneumatic automation. This guide covers the key product ranges, how they work, and how to select the right fitting for your application.
How John Guest Push-Fit Fittings Work
Every John Guest fitting uses the same core principle: a stainless steel grab ring (collet) inside the fitting body that grips the tube OD when inserted. The grab ring teeth bite into the tube surface under pressure, and the harder the pressure tries to pull the tube out, the tighter the grip. A secondary O-ring seal creates the gas-tight connection.
To release the tube, you press the release collar inward to retract the grab ring teeth, then pull the tube free. The fitting can be connected and disconnected many times without loss of performance.
Key Product Ranges
Speedfit is the John Guest range for plumbing and heating applications. Available in white and grey with BSP threads, used for water, central heating and gas applications.
Airline (PI) Series is the standard range for pneumatic compressed air applications. Available in a wide colour range (blue, black, red, yellow, green, white, orange) in metric OD sizes from 4mm to 16mm. This is the most widely used range in industrial machine building.
Superseal is a high-integrity push-fit range for refrigeration, beverage and medical applications where zero leakage is critical. Features a double O-ring seal configuration and a 90° latching collar for positive lock indication.
Configuration Range
Within the Airline PI series, John Guest offers configurations including:
- Straight union connectors (equal and reducing)
- Elbow (90°) connectors
- Equal and unequal tee connectors
- Stem elbows and stem straights with BSP male thread
- Female BSP thread adapters
- Bulkhead fittings for panel mounting
- Blanking plugs and tube end caps
- Manifold blocks (2, 3, 4 and 5 way)
Pressure and Temperature Ratings
John Guest Airline fittings are typically rated to 10 bar working pressure at 20°C with polyurethane and nylon tube. The temperature range is -20°C to +60°C for standard fittings. The pressure rating decreases with temperature — check the John Guest technical datasheet for the combined temperature/pressure rating at your specific operating conditions.
Tube Compatibility
John Guest Airline fittings are compatible with polyurethane (PU), nylon (PA12) and polyethylene (PE) tube with toleranced metric OD. The tube OD must be within ±0.1mm of nominal for reliable sealing. Do not use John Guest push-fit fittings with imperial or fractional inch tube, oval or out-of-round tube, or reinforced/corrugated hose.
Why Choose John Guest?
John Guest fittings are specified by machine builders worldwide because of their consistent quality, the breadth of configuration options, reliable tube release, and the confidence that comes from decades of product development. They meet the demanding requirements of food-grade, pharmaceutical and medical applications and are available ex-stock for rapid machine build and maintenance.
Browse our full range of John Guest push-fit fittings including straight connectors, elbows, tees, reducers and BSP adaptors in all standard metric tube sizes.
Frequently Asked Questions
What tube sizes do John Guest fittings accept?
John Guest Airline push-fit fittings are available for metric OD tube in sizes 4mm, 6mm, 8mm, 10mm, 12mm and 16mm OD. The tube outside diameter must be within u00b10.1mm of nominal for reliable sealing. They are not compatible with imperial fractional tube sizes.
What is the difference between John Guest Speedfit and Airline fittings?
Speedfit is the John Guest range designed for plumbing and heating applications u2014 water, central heating, gas u2014 typically in white or grey with BSP threads. Airline (PI series) is the range designed for compressed air and pneumatic applications, available in a wide colour range and all standard metric OD tube sizes.
Can John Guest fittings be reused?
Yes. John Guest push-fit fittings are designed for repeated connection and disconnection. Press the release collar inward, pull the tube free, and inspect the tube end. If undamaged and cut square, the same tube can be reinserted. Inspect the O-ring inside the fitting for damage if a leak is suspected after repeated use.
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