Smith Torch Pressure Question

[Catnap]

I recently upgraded my oxy-acetylene brazing setup and am running into an issue that I was hoping someone could shed some light on:

Here is my setup:
Smith A1WA torch - Smith Torch Handle - Light Duty AW1A (Versa-Torch)
Smith Kevlar brazing hose - Smith Kevlar Brazing Hose 14779-4-10
Victor oxygen & acetylene regulators
Smith Flashback arrestors for oxygen & acetylene, regulator-mount - Smith Flashback Arrestor (set) - Regulator Mount H753

The tanks and regulators are the same I was using before I upgraded - the new components are the Smith torch, the brazing hose, and the flashback arrestors.

The problem is that when the oxygen and acetylene tanks are on, and the regulator pressure set for brazing, but the torch is OFF, the torch PSI (not the tank PSI) slowly begins to climb. Left alone, it will continue to climb until it is fully maxed out, taking about 20 min or so to reach this state. This necessitates a quick bleed of the acetylene valve on the torch to bring the pressure back to normal before lighting. When in use, the acetylene pressure does not rise; the torch flame doesn't change and everything seems OK. The rising pressure only occurs when the torch is off.

The only theory I have currently is that the acetylene flashback arrestor may be causing this. However I wanted some professionals' opinions on this before spending more money on a new arrestor.

thanks for your time,
Sim*n

[Eric Estlund]

It looks like this was covered in another forum thread, but my blanket answer when having any gas apparatus issues is to stick your head into you local welding shop. Those guys are the experts on this stuff. Regulator rebuilds are fairly common, and if your shop doesn't do it in house they probably contract with someone regionally who does.