255157 - Miller 255157 Straight Quick Disconnect Fitting 1/8 NPT x 1/4 Tubing

Genuine Miller 255157 Replacement Fitting for Welding Machines

Keep your Miller welding equipment in top condition with the Miller 255157 Fitting. This specialized component is a straight, quick-disconnect adapter designed to bridge the gap between threaded ports and flexible tubing. Specifically, it connects a 1/8 NPT male thread to 0.250-inch (1/4-inch) outer diameter tubing. The fitting is constructed from a durable combination of brass and plastic, offering a balance of strength where it connects to the machine and resilience in the body of the connector.

Key Features and Applications

The "QDISC" or Quick Disconnect feature is a major advantage for maintenance efficiency. It utilizes a push-to-connect style mechanism that grips the tubing securely while allowing for easy release when necessary. This is vital for internal machine components where space is limited and using wrenches on tubing nuts would be difficult. The 1/8 NPT brass threads ensure that when the fitting is screwed into a gas solenoid, water valve, or distribution block, it creates a positive metal-to-metal seal (with appropriate sealant) that resists vibration and pressure fluctuations common in welding environments.

Why Choose OEM Miller Parts?

Welding machines rely on precise gas flow and, in some cases, coolant flow to function correctly. A compromised fitting can introduce atmospheric contamination into the shield gas stream, resulting in poor arc stability and weld defects. The Miller 255157 is manufactured to Miller's exact specifications, ensuring that the internal diameter matches the flow requirements of the machine and that the gripping mechanism will not damage the tubing over time. Unlike universal hardware store fittings, this part is tested and verified for compatibility with specific Miller power sources and wire feeders.

Installation is straightforward: ensure the threaded port is clean, apply a suitable thread sealant to the brass NPT threads if required by the service manual, and screw the fitting in place. Then, simply push your clean, square-cut 0.250" tubing into the quick disconnect collar until it seats fully. This simple upgrade or repair step restores the integrity of your machine's plumbing system, helping you get back to welding with confidence.