Nitrox M26 adapter UNDERSEA G1/4 - 300 bar

The nitrox M26 adapter UNDERSEA 1071 is a precision high-pressure fitting from UNDERSEA Ltd, a Southampton-based specialist in diving hardware since 1970. It bridges the M26x2 male thread on a European oxygen-enriched cylinder valve to the G1/4 BSP male connection on fill clamps and distribution manifolds, at service pressures of 232 and 300 bar. The M26 thread has been mandatory in the European Union since August 2008 for all cylinders carrying gases with more than 22 % oxygen — a safety measure that physically prevents confusion between EANx/oxygen and standard air equipment at the fill station. UNDERSEA Ltd supplies high-pressure diving hardware to technical centres, gas blending operations and valve workshops across Europe.

Technical Specifications

• Manufacturer reference: 1071
• Cylinder side: M26x2 male thread — EU standard for oxygen-enriched and O₂ cylinders (> 22 %)
• Charging side: G1/4 BSP male — 1/4" Whitworth parallel thread, standard on UNDERSEA fill manifolds and clamps
• Service pressure: 232 and 300 bar
• Fits the complete UNDERSEA M26 Charging Adaptors range
• Part assembled to order by UNDERSEA Ltd, Southampton (UK) — dispatch 2–3 working days
• Manufacturer: UNDERSEA Ltd — Southampton, United Kingdom, since 1970

Applications

This fitting is the connection of choice for technical dive centres and gas blending operators running EANx or trimix fill stations with G1/4 connections. It interfaces any EU-compliant oxygen-enriched cylinder with fill clamps, high-pressure hoses and distribution blocks from the UNDERSEA M26 Charging range. Suited to UK centres serving wreck divers in the North Sea and English Channel, cave diving facilities with 300 bar trimix fills, BSAC and PADI/SSI technical training centres, and individual technical divers managing a private fill setup. Also relevant for cylinder valve workshops handling multiple gas types.

Key Features

• Dual pressure rating 232 and 300 bar: one nitrox M26 adapter covers standard and high-pressure steel cylinder configurations without extra fittings
• M26x2 male thread: EU-compliant since August 2008, providing built-in segregation between oxygen-enriched and air cylinder equipment at the fill point
• G1/4 BSP male connection: universally compatible with the entire UNDERSEA M26 Charging range of clamps, hoses and manifold blocks
• Assembled to order by the manufacturer: each unit built to original factory specifications in Southampton
• In production since 1970, when technical diving barely existed: UNDERSEA Ltd engineered the M26 range as the sport evolved, turning decades of field feedback into hardware trusted by professional blending operations across Europe

Guarantees and Standards

The UNDERSEA 1071 fitting is designed and assembled by UNDERSEA Ltd (Southampton, UK) to EN 144-3 (breathing gas equipment thread — M26x2), ISO 228-1 (G1/4 BSP pipe thread) and DIN 477, the applicable standards for high-pressure gas diving equipment. This is a fill-station accessory (non-PPE) and is not subject to Regulation (EU) 2016/425. UNDERSEA Ltd manufacturer's guarantee applies.