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View Full Interactive Version Of This Page : Where does the flashback arrestor go? Where do you get tubing for oxy con?


bead crazy
2006-09-02, 2:25pm
1- I am just setting things up and I need to know where do you put the flashback arrestor up by the torch or by the propane tank? If I have a concentrator do I need one on that too?

2- My concentrator is old and does not have the screw on parts to hook the torch into how do I hook my hose (it has a screw end) to the concentrator that has the tubing connector. I will also need a Y connector I will be hooking up 2 concentrators evenually. Where do I get them?

I hope I explained this OK so someone can understand what I am looking for
Thanks for the help
Lori

bhhco
2006-09-02, 8:13pm
If your torch requires a flashback arrestor, then nearest the torch is best.

You do not need a flashback for your oxycon.

You can cut the screw end off the oxy hose and push the hose onto the oxycon's tubing connector. However, if the oxycon connector is Green, try to unscrew it - then the hose will screw on. If the oxycon connector is black it will not unscrew.

When you get a 2nd oxycon, the information presently given for how to hook it up may have changed, so wait till then for the most up todate info.

You can get connectors at the local home improvement store.

Me

Dale M.
2006-09-02, 8:15pm
1- I am just setting things up and I need to know where do you put the flashback arrestor up by the torch or by the propane tank? If I have a concentrator do I need one on that too?

2- My concentrator is old and does not have the screw on parts to hook the torch into how do I hook my hose (it has a screw end) to the concentrator that has the tubing connector. I will also need a Y connector I will be hooking up 2 concentrators evenually. Where do I get them?

I hope I explained this OK so someone can understand what I am looking for
Thanks for the help
Lori

Depends on flash back arrestor design.... Look at the arrow on arrestor body, it has to point in direction of torch. The combination of male/female connectors on arrestor body will dictate whether it goes at torch or regulator..

IF your concentrator does not have threaded connector, just a barbed fitting you have to either get small length of hose with proper end (from welding shop) to adapt to new hose end or just cut off the threaded end of new hose and put on barbed connector of oxy con.... For the "Y" connector just get a plastic Y or T shaped connector ( 1/4 inch) at hardware store or auto parts and get some 1/4 inch vinyl at hardware store to connect oxy cons to Y or T fitting and third side of Y or T fitting goes to torch hose...

Dale

bead crazy
2006-09-03, 1:06pm
Thanks for the info ME and Dale
ME you said if the torch needs a flash back arrestor. I thought that they all needed one. I have a national 8M why would you not need one?
Lori

Dale M.
2006-09-03, 3:43pm
Surface mix torches mix the fuel and oxygen AFTER the fuel and oxygen leave the ports (on surface) and it almost impossible for flame to travel backwards down the port. Usually a flame will not travel down port of surface mix torch because one port is emitting pure oxygen and other is pure fuel, its next to impossible for flame to travel back down the pure fuel or pure oxygen line.

BUT a premix torch mixes fuel and oxygen BEFORE it leaves the port at tip of torch making it easy for flame to be sucked back because it is at proper mix ratio for combustion inside torch body before it leaves port.

A National 8M body with surface mix tips does not really need FB arrestor, HOWEVER the moment you put premix tip on National 8M body it becomes a different torch and should have FB arrestor...

Dale

jokersdesign
2006-09-03, 5:37pm
I thought that in the name of safety, you should have a flash back for any torch be it premix or surface mix.

I also thought the flash back goes on the regulators.

But it seems the new trend is to only use flash backs if the torch is premix, and to not use flash backs if the torch is surface mix.

It also seems the new trend is to use flash back as close as possible to the torch , instead of the regulators.

bhhco
2006-09-03, 7:12pm
I thought that in the name of safety, you should have a flash back for any torch be it premix or surface mix.

I also thought the flash back goes on the regulators.

But it seems the new trend is to only use flash backs if the torch is premix, and to not use flash backs if the torch is surface mix.

It also seems the new trend is to use flash back as close as possible to the torch , instead of the regulators.

If you were to have a flashback... where would you prefer to have it stop first? At the torch?... or 20 feet into the hose headed for the regulator? Want one at the regulator too? OK. The first one might fail. How often do we test the flashback arrestor(s) to be sure it's working right.

Dale is 100% correct.

Me

Dale M.
2006-09-03, 7:43pm
I thought that in the name of safety, you should have a flash back for any torch be it premix or surface mix.

I also thought the flash back goes on the regulators.

But it seems the new trend is to only use flash backs if the torch is premix, and to not use flash backs if the torch is surface mix.

It also seems the new trend is to use flash back as close as possible to the torch , instead of the regulators.

Its always been said, to be the safest you can be, is to use FB arrestor....
Its just less likely for sufrace mix torch to ever "need" the services of a FB arrestor...

And the best one to use is the one that connects at the torch.... And it its usually the one NOT stocked by most lampwork suppliers...

As for testing them we do it every time we use torch, if they have done their job, they do not permit any gases to flow and are throw away items to be replaced with new....

Dale

jokersdesign
2006-09-03, 8:32pm
So to be the safest, you should use a flashback on any torch be it surface mix or premix and then use a flashback at the torch side and the regulators?

Looks like I need another set of flashbacks at the torch.

Look at this website. They even sell premade hoses to connect flashback at the torch side.

http://www.howacoglass.com/images/flash_back_hose_adapter.jpg

bhhco
2006-09-03, 11:47pm
Thanks for the info ME and Dale
ME you said if the torch needs a flash back arrestor. I thought that they all needed one. I have a national 8M why would you not need one?
Lori
The reason I said "If your torch requires a flashback arrestor...") is because I did not know which torch you use, what fuel you use, or what fuel and oxygen service and pressures you use.

As Dale said, the 8M can be configured as either a internal or surface mix torch. Surface mix torchs do not generally require a flashback arrestor. There are some torchs that are true surface mix only, some that are both internal mix and surface mix. And some like the 8M, that can be either. I rather think the general guidance of 'always use a flashback' is often suggested because many torch users do not know what type of torch they have. In that case, it is very sound advice - better safe than sorry.

On your torch, the 8M, a special adapter is used to convert it into a surface mix torch. This adapter incorporates a internal buna-n o-ring, designed to force the fuel and oxy through separate surface tubes/orifices - thus surface mix, and thus not the standard flashback risk.

However, the 8M internal o-ring can shrink with use, and the fuel and oxy could mix internally even though it is configured, hardware-wise, as a surface mix. It still requires a rather complex set of very specific things for a flashback to occur but, since it could, then flashback arrestors are suggested for your 8M.

The flashback arrestors can be directly attached to the 8M torch. The 8M is designed with B-fittings on the torch valves. Simply attach the flashback arrestors to the torch, and then the hoses to the arrestors. As Dale said, it will require arrestors designed to be attached to the torch.

Me

Dale M.
2006-09-04, 8:58am
So to be the safest, you should use a flashback on any torch be it surface mix or premix and then use a flashback at the torch side and the regulators?

Looks like I need another set of flashbacks at the torch.

Look at this website. They even sell premade hoses to connect flashback at the torch side.

http://www.howacoglass.com/images/flash_back_hose_adapter.jpg

Only if your torch has barbs for connecting fuel or oxygen, if torch has standard threaded "B" type connectors these hoses are not needed.

Flash back arrestors for torch end of hose have the male/female connectors reversed as to direction of flow than that of the male/female connector configuration of a arrestor that connects at regulator...

And good welding supplier (local) can make up same hose....

Dale