John Guest acetal stem adapter fittings deliver push-to-connect convenience with British Standard Pipe Thread (BSPT) compatibility for secure, leak-free connections in potable water, air, and CO2 applications. Manufactured in the UK with food-grade nitrile O-rings and grip-then-seal collet technology, these fittings install in seconds without tools and handle higher temperatures than standard polypropylene alternatives.
SPECIFICATIONS
John Guest Acetal Stem Adapter Technical Details
| Manufacturer | John Guest Speedfit (UK) |
| Material | Acetal copolymer body with food-grade nitrile O-ring |
| Thread Standard | British Standard Pipe Thread (BSPT) |
| Connection Type | Push-to-connect with grip-and-seal collet |
| Suitable For | Potable water, air, inert gases, CO2, pneumatic systems, vacuum |
| Temperature Resistance | Higher heat tolerance than polypropylene fittings |
| Color | Grey |
| Applications | Tap connections, toilet supply, filtration systems, pneumatic lines |
INSTALLATION & USE
Installation Process
- Ensure tubing is cut square and free of burrs or debris
- Push the fitting fully onto the tubing until it bottoms out in the collet
- Turn the fitting onto the BSPT threaded connection until hand-tight
- To disconnect, unlock the nut, push the collet toward the body, and pull the tube to release
COMPATIBILITY
Thread Sizing Reference
BSPT threads measure larger than their nominal size when measured with a ruler. A 1/8" BSPT measures approximately 0.383" actual diameter, 1/4" BSPT measures 0.518", 3/8" BSPT measures 0.656", and 1/2" BSPT measures 0.825" across the threads. This is standard for British Standard Pipe Threads and not a manufacturing defect. Verify your existing thread size with calipers or the actual diameter measurement before ordering.
🔧 Always measure the actual thread diameter with calipers rather than assuming nominal size. BSPT threads are tapered and measure significantly larger than their fractional designation, which prevents compatibility issues and returns.
