Why is my cutting torch "snapping"?

I am getting an annoying snapping in the tip of my cutting torch. Flame and tip look good and cutting good too just making a "snap" every 3 or 4 seconds. Does not do it when cutting handle is depressed so I am thinking its on the oxy side. Leak maybe? Thanks Ed

Hello Ibc
Does it happen all the time or just when you are using it? Not trying to be funny, I mean when you have the torch close to the metal to be cut.

Usually this happens when you are trying to run more acetylene than the tank and regulators can supply.
Big torches need big tanks, as acetylene is suspended in some magic goop of minerals and can only turn back to gas from liquid so fast.
How big is the torch, and how big is your acetylene tank?
Has this exact setup worked well in the past, without snapping?
Are your regulators set the same, with the acetylene open enough to get adequate flow?

With really big cutting torches, they actually have to gang up multiple acetylene tanks on a manifold, in big sizes, to get enough flow.

What are your regulator presure settings at?Unless you are running a big ass tip,about 7lps of acetylene and 21lps of oxygene should work fine.Oxygene runs apporox. 3 times the acetylene presure.
One thing also is sometimes you can blow the seals inside of the barral of the torch,best way to fix that is send it in for repair.

Tip has a small blockage in one of the holes...Bob

IronReb said:

What are your regulator presure settings at?Unless you are running a big ass tip,about 7lps of acetylene and 21lps of oxygene should work fine.Oxygene runs apporox. 3 times the acetylene presure.
One thing also is sometimes you can blow the seals inside of the barral of the torch,best way to fix that is send it in for repair.

Click to expand...

I also say might be barrel to tip seal leaking.

Ciszewski said:

Hello Ibc
Does it happen all the time or just when you are using it? Not trying to be funny, I mean when you have the torch close to the metal to be cut.

Click to expand...

All the time, right from the start, not near the work. Ed


Tip has a small blockage in one of the holes...Bob
I will try cleaning this first. Ed
I think I sent this one off last year to be rebuilt and that was about the time it started.....when I got them back.

Hello Ibc
That throws my theory out the door. I thought that maybe it was something simple like holding your torch too close to the work. Mind you that happens more often with a welding tip while gas welding or brazing than when using a cutting torch.

You need to check the surfaces where the tip and barrel meet. There might be a dent or bad spot. If it is just metal to metal you might need to use some lapping compound (auto rubbing compound, Comet Clenser) to re-seat it.

Timw said:

You need to check the surfaces where the tip and barrel meet. There might be a dent or bad spot. If it is just metal to metal you might need to use some lapping compound (auto rubbing compound, Comet Clenser) to re-seat it.

Click to expand...

I will check this out. i have lapping compound, thanks, Ed

The most common cause is that the seat where your cutting tip mounts is scarred and causing a leak. The torch sits there and goes pop, pop pop, slowly. I see this all the time on CNC cutting machines. Smart shops store their tips covered to keep general shop crud off of them. Less quality controlled shops usually have a rack near the cutting machine with holes drilled in them. They stick the tips in them with the seats facing up, and you see evidence of dust, dirt, and grit settling on these imporant seal surfaces. Next some monkey with a wrench sticks the dirty tip in the torch, it doesn't seal, so they carnk the tip nut even tighter and score the seating surface. Eventually it gets so bad I get a call because the machine constantly pops out trying to pierce holes.

The best solution is to ream the torch seats to fix them, and replace all the torch tips and keep them clean. Otherwise, the first time a dirty tip gets installed and cranked down, the seat is buggered again, and in short order all the torches on the machine have the same problem.

It's one fo the reasons I love Smith tips. They have a soft seat and no wrenches are needed other than for the firs use of the tip.

Fixed

Timw said:

You need to check the surfaces where the tip and barrel meet. There might be a dent or bad spot. If it is just metal to metal you might need to use some lapping compound (auto rubbing compound, Comet Clenser) to re-seat it.

Click to expand...

Well I took the tip out, lapped it in with compound, wiped it out, lit it, it snapped once or twice, repeated the lapping steps tried it again and it is working fine. I even took another small Purox cutting torch that was doing it worse and lapped it in......working great too.
Thanks for all the help. Don't know what I would do if I didn't have access to this forum, Ed