Replacement Oxy/Ac hoses

[Ray C]

Good point on the dual check valves and I'll get to that. As always I treat the gas hoses as carefully as my fingers, arms & legs. And yup, I never crack the Acy valve all the way. Did you know that freely vented Acy self ignites when it gets much past 15PSI? Also, they add about 1 gallon of naptha to a 300 size tank to stabilize it. Who ever thought something as volatile as naptha could stabilize something...

Haven't done much Acy ever since I got a plasma cutter. Used it mainly for cutting and heat treating small parts. When there was an Acy shortage a few years ago, I switched to polypropolene and found out it's only good for cutting -not heat treating. It won't produce a carburizing flame and the part gets contaminated. It cuts better than Acy though -runs at 3x the pressure -and that's why you can't weld with it either.

You may want to consider a set of flashbacks at both the torch and the regulators as I once saw a hose get burned in two when a piece of angle iron fell on it and it was rapidly burning back towards the bottles. Thank goodness someone had enough sense to turn the acetylene and oxygen bottles off quickly. Since the oxygen bottle valve is double seated I always open it wide open until it tightens, on the acetylene bottle I only open it until it registers pressure on the gauge and then just a little bit more, that way if you must shut off the bottle quickly, it is a fairly short turn.

Something else you may consider is the Koike type Quick Connectors http://www.bibowindustries.com/Gentec_KOIKE_Style_Quick_Connectors.htm , especially if you change torches frequently. These also contain a flahback built in as well as a check valve so you can remove/change the torch without shutting off the bottles.

 

[Ray C]

Jeff,

Would you please add those steps to the Sticky shop saftey list? It's here: http://www.hobby-machinist.com/showthread.php/9537-Specific-Rules-of-Thumb-for-Shop-Safety!


"Tanks" in advance.

Ray

You are absolutely right.
This procedure should be followed every time you stop welding with gas:

1. Turn off the Fuel at the torch
2. Turn of the oxygen at the torch
3. Close both Tank valves.
4. Release the pressure at the torch for both gases; the gauges should now read zero.
5. Close the torch valves.
6. Back out the T valves on the regulators until they turn freely. (be careful not to unscrew them completely)

The order of operations is important.

When starting to weld you need to

1. Verify the torch valves are closed
2. Verify the regulator handles are backed out (VERY IMPORTANT)
3. Stand sideways to the gauges AND TURN YOUR HEAD AWAY.
4. Open the Acetylene no more than 3/4 of a turn
5. Open the oxygen all the way
6. Adjust both regulators.
7. Open the oxygen torch valve for a second or two to purge it, then close.
8. Open the fuel torch valve for a second or two to purge it, then close.

You are ready to light up!

 

[paulweldit]

Good point on the dual check valves and I'll get to that. As always I treat the gas hoses as carefully as my fingers, arms & legs. And yup, I never crack the Acy valve all the way. Did you know that freely vented Acy self ignites when it gets much past 15PSI? Also, they add about 1 gallon of naptha to a 300 size tank to stabilize it. Who ever thought something as volatile as naptha could stabilize something...




Acetylene will Ignite on its own at 28 PSI so what is inside the bottle is a blanket of fiber
soaked with liquid Acetone which absorbs the acetylene in solution. Originally they used asbestos but it was Outlawed. Since the contents of an acetylene bottle is liquid, you should never lay the bottle flat especilly when welding because the solution can drain into the line. the bottle should never be stored lay down and even transporting it laying down is not reommended. If any of the liquid drains out of it, it can cause the bottle to have an air pocket and explode. The bottle can also be damaged by dropping it or a hard hit since that can cause the liner to separate from the side wall and cause an air pocket. An oxygen, 75/25.CO2, Nitrous or Argon bottle can be filled in minutes but an Acetylene bottle takes days to fill and has to be cooled during the process, Each Acetylene bottle is permaently marked with a weight. It is checked carefully before filling process starts to make sure the proper amount of liquid is still in the bottle.

Paul N,

 

[FrankW]

There is an angle that you can tilt the acet bottle and it operate ok. Beyond that angle it will draw acetone out with the acet and fowl up the works. I have forgotten that angle. Anyone remember the angle? You see it on service trucks where the bottles are at angles. :nono:

Frank

 

[7HC]

There is an angle that you can tilt the acet bottle and it operate ok. Beyond that angle it will draw acetone out with the acet and fowl up the works. I have forgotten that angle. Anyone remember the angle? You see it on service trucks where the bottles are at angles. :nono:

Frank

Don't know, but for practical purposes there is absolutely no need to tip the bottle at all while in use. When moving it, just tilt the cart the minimum necessary to be able to push it.


M

 

[November X-ray]

Acetylene will Ignite on its own at 28 PSI so what is inside the bottle is a blanket of fiber
soaked with liquid Acetone which absorbs the acetylene in solution. Originally they used asbestos but it was Outlawed.

Don't be fooled into thinking there is no more asbestos in any products nowadays, as many imported items such as sheetrock may still contain it. Also asbestos is a natural occurring mineral and can be dug up during normal everyday excavations, but typically not as most deposits were known. Also some of the sheetrock mud mixes still says something like, "contains natural mineral fibers", which can be asbestos.

 

[jfcayron]

Jeff,

Would you please add those steps to the Sticky shop saftey list? It's here: http://www.hobby-machinist.com/showthread.php/9537-Specific-Rules-of-Thumb-for-Shop-Safety!


"Tanks" in advance.

Ray

Done!

 

[Ray C]

Thank you!

Done!

 

[FrankW]

7HC,

I agree that in the shop there is no need to tilt bottles, but when mounting on a service truck, sometimes it is convenient to mount tilted. Which was my intended reference.

Frank

 

[Uglydog]

They are 2 different things:

• Check valves block the reverse flow of the gases so there is no risk of mixing Oxygen and fuel in the hoses or regulators.
• Flash back arrestors snuff any flame running back through the hoses.

I strongly recommend having both as they serve different purposes. Many good quality torches have one or the other or both built in. It is still a good idea to add a set at the regulator end.

This is all accurate. But, please continue to be carefull. Sometimes we become less vigilant with all the safety devices. Even good flash back arrestors fail. Also, be carefull if changes torches. It's possible to get contaminants inside the arrestor eliminating its safety benefits.