Steel Compression Pipe Fittings
BES supplies the trusted Primofit® Firejoint range of steel compression pipe fittings, purposely designed for natural gas and LPG installations where fire resistance, mechanical strength and ease of assembly are critical. Our selection of Primofit fittings includes adaptors, couplers, elbows and tees and comes in sizes from ½" to 2", all manufactured by a BS EN ISO 9001 registered company and approved by British Gas and DVGW (HTB) for internal and external use on above-ground steel gas pipes.
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A Wide Range Of Primofit® Steel Compression Fittings
The Primofit® Firejoint system provides a safe, mechanical alternative to welded or screwed joints. These steel compression fittings are supplied preassembled, fully reusable and easy to install using standard wrenches.
Our Primofit® Firejoint fittings use the same robust casting bodies and nuts as the standard Primofit® system but feature a graphite fire-resistant seal to maintain joint integrity during and after a fire.
Adaptors
Primofit® Firejoint adaptors are used to transition from steel pipe to threaded connections or equipment. Available from ½" to 2", popular options in our selection include the Primofit® Firejoint Adaptor – 1” and Primofit® Firejoint Adaptor – 2”.
Couplers
Used to connect plain-ended steel pipes, Primofit® Firejoint Couplings provide a secure, gas-tight joint that withstands high pressure and temperature extremes. Tested at 75 mbar and 40 °C working temperature, the joint can resist 850 °C for 30 minutes while maintaining its end-load capability. These couplers are widely used in gas risers and laterals for blocks of flats and similar multi-occupancy buildings, delivering a strong, leak-tight seal that withstands vibration and pressure fluctuations.
Elbows
Browse our selection of Primofit® elbows, designed to create 90° changes in direction while maintaining full-bore flow and mechanical strength. Supplied in ¾", 1", and 2" sizes, these elbows are ideal for compact or enclosed installations.
Tees
Primofit® Firejoint tees allow for branch connections in pressure systems, maintaining the same compression seal integrity as straight fittings. Available in 1" and 2" sizes.
Spare Packs
We stock a choice of replacement Primofit® Firejoint spare packs that include all necessary sealing and compression components for maintenance or refurbishment. Available in all standard fitting sizes to support long-term system serviceability.
What Are Steel Compression Fittings?
Steel compression fittings provide a mechanical joint between plain-ended steel pipes, removing the need for welding, threading or flanging. A compression ring and sealing gasket inside the fitting create a gas-tight joint when tightened with standard tools.
What Makes The Firejoint System Different
The Primofit® Firejoint design incorporates a graphite-based secondary seal that remains stable at temperatures up to 850 °C for 30 minutes. If the primary rubber seal is compromised during a fire, the graphite element preserves both the end-load capability and the gas-tight integrity of the joint. This makes Firejoint fittings the ideal choice where fire performance certification is required.
How to Install Steel Compression Fittings
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Cut the pipe squarely and remove burrs.
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Insert the pipe fully into the fitting until it seats against the stop.
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Hand-tighten, then complete tightening with standard wrenches following manufacturer torque guidelines.
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Pressure-test the system using an approved gas pressure test method and check all joints for leaks before commissioning.
These fittings are designed for above-ground gas pipework and may be used externally, provided appropriate corrosion protection is applied. All installation work on gas systems must be carried out by a Gas Safe registered engineer.
Advantages of Compression Fittings vs. Welding or Threading
Steel compression fittings offer a fast, safe and reliable alternative to traditional jointing methods. They eliminate the need for hot work permits, reducing fire risk during installation, and allow rapid assembly without threading or specialised tooling. Fittings can be disassembled and reused during maintenance, yet provide high mechanical strength and proven gas-tight integrity under pressure and heat. Their simplicity and safety make them the preferred option for risers, laterals and other confined or occupied environments where welding is impractical.
Expert Support, Trusted Supply
At BES, we know that every installation demands fittings that perform first time, every time. Our long-standing partnership with Primofit® reflects our commitment to supplying the trade with robust, proven steel compression pipe fittings that save time on site and deliver lasting reliability.
Whether you’re maintaining a commercial gas line or installing new pipework, you can count on BES for accurate product data, expert technical guidance and dependable next-day delivery.
FAQs
What are Primofit® Firejoint steel compression fittings used for?
Primofit® Firejoint fittings are designed for natural gas and LPG installations where fire resistance is essential. They maintain joint integrity even during extreme temperatures, making them suitable for gas risers, laterals and above-ground steel pipe connections in multi-storey or commercial buildings.
What is the difference between standard Primofit® fittings and Firejoint versions?
The Firejoint range includes a graphite-based secondary seal that withstands fire conditions up to 850°C for 30 minutes, ensuring gas-tight performance if the primary rubber seal fails. Standard Primofit® fittings (non-Firejoint) are suitable for general plumbing, heating and industrial use, including connections between steel, PE and lead pipes, but are not fire-rated for gas systems.
Are Primofit® Firejoint fittings approved for gas use?
Yes. They are British Gas approved for internal and external above-ground steel gas pipework and carry DIN-DVGW (HTB) certification.
Do these fittings require special tools for installation?
No. Installation only requires standard wrenches - no threading, welding, or hot work permits are needed, which makes them ideal for both new installations and retrofit work.
Can Primofit® fittings be used underground?
Primofit® Firejoint fittings are designed for above-ground gas installations. If buried, they must be suitably protected against corrosion and used only in compliance with local gas installation regulations.
Are spare parts available for maintenance?
Yes. BES stocks Primofit® Firejoint Spare Packs containing replacement seals and compression components for all fitting sizes, ensuring continued system reliability.
What are the main advantages of compression fittings over welded joints?
Compression fittings are quicker and safer to install, require no heat or specialised tooling, and can be disassembled for maintenance. They’re ideal for locations where hot works are restricted or time is limited.