Introduction: Foot Operated in Line Gas Saver for Oxy-fuel Torch
A gas saver valve for the oxy-fuel torch not only provides convenience, it also reduces costs. The following version has been in constant use for over 30 years in my shop. It's a little different than most current commercial offerings and costs much less to build.
Rather than being bench mounted, this version is spliced into the hoses about 6 feet upstream of the torch and foot operated. It is durable enough and compact enough to drag around the shop floor or wherever else it is needed.
The heart of the system is two 1/4" fip x 1/4" fip brass 2 way in-line button valves with Buna-N (nitrile) seals compatible with oxygen, propane or acetylene.
The pedal hinges perpendicular to the lines. Depressing the pedal opens the fuel valve before the oxygen valve, releasing it closes them in reverse order. This allows the torch to be turned on and shut down according to industry recommended practice.
There is a bypass valve that sends a small amount of gas to the tip when the valves are closed to act as a pilot flame. A slow release of the pedal is required to avoid blowing the pilot flame out, and to prevent popping when using acetylene. On acetylene, the pilot sends a fair amount of black soot into the air. I usually just leave it off when using acetylene, relighting the torch from the still hot steel or a striker. At the brazing station I use a small alcohol burner as a pilot light.
Do not use the pilot light feature unless the torch is securely mounted and pointed in a safe direction.... See opening photos for my solution. Turn off torch valves when unattended to avoid unintentional release of oxy-fuel. Check valves and flashback arrestors are recommended if not built into the torch. Leak test regularly. When assembling, use a thread sealer compatable with oxygen, propane or acetelyne.
Disclaimer: This is a device designed and used by me in my personal shop for over 30 years without incident. It is not tested or approved by any agencies and should be viewed as experimental. Build and use at your own risk.
Per the instructables copyright notice, feel free to use this information to create a gas saver based on the following design for your own non-commercial use as long as this instructable is credited as the source.
Creating this instructable necessitated a full breakdown, cleanup and adjustment of my much used foot operated in line gas saver. It should be good for another 30 years! Enjoy. -Bruce Francis
-Two 1/4" fip x 1/4" fip brass 2 way in-line button valves.
-Two 1/4" fip x 1/4" mip x 1/4" fip brass street tees.
-Two 1/4" mip x 1/8" fip brass reducing bushings.
-One 1/4" OD tube x 1/8" mip, angle brass compression needle valve.
-One 1/4" OD tube x 1/8" mip brass compression reducing elbow.
-One 1/4" OD copper rod with 1/16" gas passage hole for pedal hinge rod. A section from a spoolgun tip works well.
-One 1/4" x 2" x 6" mild steel bar for mounting base.
-One 1/4" x 3/4" x 6" mild steel bar for lever.
-One 1/4" x 3/4" x 1" mild steel bar for lever keeper.
-One 1-1/4" x 1-1/4" x .120" x 3" square tube cut in half length wise for valve hold down.
-One 1/4-20 tpi x 1/2" countersunk plated machine screw for lever keeper.
-One 1/4-20 tpi x 1-1/2" countersunk plated machine screw for valve hold down.
-Two 1/4" mip x 9/16" brass oxygen fittings.
-Two 1/4" mip x 9/16" Left Hand thread fuel gas fittings
Step 1: Base Plate
Drill and tap 1/4-20 tpi hole to receive valve hold down screw 1-1/2" from one end and centered.
Step 2: Lever Assembly
Drill and countersink hole in lever 3/4" from one end to accept lever keeper screw.
Drill and tap 1/4-20 tpi threads into lever keeper 1/4" from one end.
Assemble lever to lever keeper with lever keeper screw.
Drill a 1/4" hole edgewise through both parts 1/2" from the end.
Step 3: Valve Hold Down
Before cutting lengthwise, drill the following holes:
-3/4" diameter 3/4" from each end in the top and both sides, 6 total. Do not use the side with the seam.
-1/4" diameter centered in the top, countersink to accept the valve hold down screw.
-Cut lengthwise along the center of each side.
Step 4: Oxygen Valve Assembly
Assemble the appropriate fittings as shown using a thread sealer suitable for oxygen service
Step 5: Gas Valve Assembly
Assemble the appropriate fittings using a thread sealer suitable for propane and acetylene.
Trim the needle valve cross pin as shown to avoid unintentional adjustment.
Cut the copper hinge rod to fit, add compression ferrules and nuts. Place in compression fittings and rotate fittings in line to capture rod.
Do not substitute thin wall copper tubing for the hinge rod! It is not strong enough.
If the pilot light feature is not desired, simply substitute another compression elbow for the needle valve and use a solid hinge rod.
Step 6: Final Assembly
Place fuel valve assembly and oxygen valve assembly on base.
Secure with valve hold down using valve hold down screw, grind screw flush with bottom of base.
Attach lever to hinge rod with keeper plate and keeper plate screw.
Rotate fuel valve relative to the fuel valve assembly so the lever is parallel to the base when the valves are 1/32" from being fully opened.
Bend the lever down to the base 4" from the hinge end when the lever is parallel to the base as a stop.
And there you have it.... Enjoy!