Adapter Female NEVOC Type 31 For Air

UNDERSEA Ltd is a Southampton-based UK manufacturer with continuous expertise in high-pressure gas connectors for the diving industry since 1979, supplying dive centres, technical diving facilities and compressor engineers across Britain and continental Europe. Their Type 31 adapter, reference 1133, interfaces the female NEVOC W30×2 cylinder valve thread — the standard European connection for compressed air cylinders — with the G1/4 male BSP cone outlet used throughout diving fill stations, cascade panels and compressor systems. Compliance with ISO 5145 Type 31 means this fitting is physically keyed to air circuits only, providing a passive safety barrier against accidental cross-connection with oxygen (Type 32) or inert gas (Type 30) adapters in multi-gas fill rooms — an essential safeguard at technical diving centres running air, nitrox and trimix from the same fill station, such as those serving UK wreck diving sites at Scapa Flow or the Farne Islands.

Technical Specifications

• Manufacturer reference: 1133
• Brand: UNDERSEA Ltd (Southampton, UK — since 1979)
• Gas type: Compressed air — Type 31 (ISO 5145 designation)
• Inlet thread: NEVOC W30×2 female, right-hand (cylinder valve side)
• Outlet thread: G1/4 male BSP, 60-degree cone seat
• Material: brass
• Maximum working pressure: 300 bar
• Standard: ISO 5145 — cylinder valve outlets for gases and gas mixtures
• Net weight: 200 g
• Made to order — typical lead time 2-3 working days

Recommended Uses

Designed for BSAC clubs, PADI and SSI dive centres, professional fill operators and technical divers managing their own filling equipment, this NEVOC adapter Type 31 is used wherever a NEVOC W30×2-valve compressed air cylinder must connect to the G1/4 outlets of a fill panel, cascade system or high-pressure compressor. The ISO 5145 Type 31 keying system ensures no helium or oxygen adapter can accidentally be fitted to an air connection point — a core safety feature at any multi-gas fill station. The G1/4 male 60° cone outlet provides direct compatibility with the vast majority of fill panels, high-pressure hoses and gauges across European diving operations.

Key Strengths

• ISO 5145 Type 31 gas-specific keying: physically incompatible with oxygen (Type 32) and inert gas (Type 30) connections — cross-contamination risk eliminated by design without relying on operator vigilance
• Brass construction for 300 bar service: mechanically proven for the high-cycle, high-pressure duty typical of busy recreational dive centres servicing many cylinders daily
• Universal G1/4 male 60° cone outlet: directly compatible with the full range of dive fill panels, high-pressure hoses, manifolds and gauges in use across European filling facilities
• Established UK manufacturer: UNDERSEA has supplied compressor rooms and blending panels from dive clubs to commercial diving operations since 1979, designed to British and DIN Standards
• Complete gas range with references 1130 and 1134: adding Type 30 (helium/nitrogen) and Type 32 (oxygen) delivers a fully gas-segregated NEVOC W30×2 fill station for technical diving

Warranty and Certifications

The UNDERSEA 1133 adapter conforms to ISO 5145 for cylinder valve outlets for compressed and liquefied gases. The Type 31 designation confirms compliance with the NEVOC air-circuit standard. This product is not personal protective equipment (PPE) within the scope of EU Regulation 2016/425. UNDERSEA manufacturer's warranty applies to defects in materials and workmanship. For compressed air cylinder handling guidance and fill station safety, refer to the British Sub-Aqua Club (BSAC) technical diving standards and guidance.

Official Documentation

• ISO 5145:2014 — Cylinder valve outlets for gases and gas mixtures (ISO official)