3381 - B-Size Acetylene Hose Nut | 9/16"-18 LH Brass Fitting

Precision Brass Fitting for Fuel Gas Systems

The ESAB 3381 is a high-quality B-Size Acetylene Hose Nut designed for the professional assembly and repair of oxy-fuel welding hoses. Manufactured to strict tolerances, this brass fitting ensures a secure and leak-free connection between your fuel gas hose and the regulator or torch handle. The nut features the industry-standard 9/16"-18 thread pitch with a Left-Hand (LH) orientation, a critical safety feature mandated for all fuel gas connections (including Acetylene, Propane, and Propylene) to prevent accidental cross-connection with Oxygen lines.

Constructed from durable, corrosion-resistant brass, this nut is built to withstand the rigors of industrial environments. The hexagonal shape is machined for a precise fit with standard wrenches, allowing technicians to apply the necessary torque without rounding off the edges. As a "B-Size" fitting, it is compatible with the vast majority of industrial welding hoses used in North America (typically 1/4" and 3/16" ID hoses). This component is the nut only; it is designed to slide over a compatible hose nipple (barb) before the hose is crimped or clamped, effectively securing the nipple to the threaded outlet of your equipment.

Technical Specifications and Compliance

In the realm of compressed gas equipment, adherence to CGA (Compressed Gas Association) standards is paramount. The ESAB 3381 conforms to the specifications for CGA 023 connections. The presence of the notch on the hex nut serves as a universal visual indicator that the fitting employs left-hand threads, alerting the user to turn counter-clockwise to tighten. This simple yet effective coding system is a fundamental aspect of welding safety protocols. Whether you are manufacturing custom hose lengths in a shop setting or performing field repairs on damaged lines, this nut provides the reliability required for high-pressure gas service.

Proper installation of this nut requires a matching B-size nipple and a suitable ferrule or hose clamp, depending on the pressure rating and hose type. It is essential to ensure that the seating surface of the nipple (which mates with the regulator or torch) is clean and undamaged, as the nut provides the mechanical force to seal that interface. Regular inspection of all gas fittings for wear, thread damage, or deformation is recommended to maintain a safe working environment.