7345 - Miller Smith Little Torch Replacement Oxygen Valve Assembly (Green)

Technical Overview of the Miller Smith 7345 Valve Assembly

The Miller Smith 7345 is a dedicated replacement Oxygen Valve Assembly designed specifically for the renowned Smith Little Torch. As a critical component in the oxy-fuel manifold of the torch handle, this assembly governs the flow rate of oxygen into the mixing chamber, directly influencing the flame characteristics, temperature, and chemistry. The assembly is manufactured to original equipment manufacturer (OEM) specifications, ensuring that the thread pitch, seat geometry, and stem length align perfectly with the Little Torch body. This precision is vital for preventing gas leaks and ensuring a positive shut-off when the torch is not in use.

The unit features a color-coded green knob, adhering to industry standards for oxygen gas identification. This visual cue is essential for safety in multi-gas environments, preventing operator error during setup and adjustment. The valve stem itself is engineered for fine adjustment, allowing the operator to dial in the precise amount of oxygen required for neutral, oxidizing, or carburizing flames. Given the Little Torch's capability to produce extremely small, hot flames (up to 6300°F with certain fuels), the sensitivity of the valve is paramount. A worn or damaged valve can lead to flame instability, difficulty in lighting, or the inability to extinguish the flame completely.

Maintenance of oxy-fuel equipment is a key aspect of shop safety. Over time, valve packings can dry out, and seats can wear down due to the abrasive nature of gas flow and repeated mechanical operation. Replacing the valve assembly with the 7345 unit restores the torch to its factory performance levels. This component is compatible with the standard Little Torch handle used in jewelry manufacturing, electronics repair, and laboratory applications. It is not interchangeable with the fuel valve (red knob), which has different internal seating or thread directions in some gas apparatus configurations to prevent cross-connection, although on the Little Torch, visual identification is the primary safety feature provided by the knob color.

Installation involves removing the old valve assembly from the torch body—typically by unscrewing it counter-clockwise—and threading the new assembly into place. Care should be taken not to over-tighten the new valve, as this can damage the brass seat within the torch body. Once installed, leak testing with an approved leak detection solution is recommended to verify the integrity of the seal before igniting the torch.