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Flashback arrestors


#1

I recently accompanied a friend to buy a torch,regulators and
bottles(Oxygen and LPG). At the store (BOC gases, in West
Australia). We were informed that it was now a legal
requirement in WA and probably the rest of Australia, to have
flashback arrestors attached to regulators to avoid the flames
travelling back through the hoses before exploding and killing
the operator. Fatal accidents apparently occur in workplaces
once every 3 months. According to our advisor, flames can
travel back up the hoses when: a)there is unequal pressure in the
two tanks ie. one may be almost empty b)when the tip touches the
work, c)when flames jump up from the work (very easy when
alloying!) In fact, the regulation even exists for single
cylinder (LPG) operation but we were advised that it is
virtually impossible for flashbacks to occur using a single
cylinders and that this requirement was absurd.

Flashback arrestors are made for O2,acetylene, LPG, etc and have
a nylon component in them which shuts down the hose.

I have used my set up for 5 years and had never heard of
flashback arrestors. Nor would I have known had I not
accompanied my friend. There was certainly no such thing on our
cylinders when I was at college. My question is whether others
are aware of this potential danger and whether other countries
have regulations in place to counteract it.

Look forward to any responses
Regards Christel


#2

I recently accompanied a friend to buy a torch,regulators and
bottles(Oxygen and LPG). At the store (BOC gases, in West
Australia). We were informed that it was now a legal
requirement in WA and probably the rest of Australia, to have
flashback arrestors attached to regulators to avoid the flames
travelling back through the hoses before exploding and killing
the operator. Fatal accidents apparently occur in workplaces
once every 3 months. According to our advisor, flames can
travel back up the hoses when: a)there is unequal pressure in the
two tanks ie. one may be almost empty b)when the tip touches the
work, c)when flames jump up from the work (very easy when
alloying!) In fact, the regulation even exists for single
cylinder (LPG) operation but we were advised that it is
virtually impossible for flashbacks to occur using a single
cylinders and that this requirement was absurd.

Flashback arrestors are made for O2,acetylene, LPG, etc and have
a nylon component in them which shuts down the hose.

I have used my set up for 5 years and had never heard of
flashback arrestors. Nor would I have known had I not
accompanied my friend. There was certainly no such thing on our
cylinders when I was at college. My question is whether others
are aware of this potential danger and whether other countries
have regulations in place to counteract it.

Look forward to any responses
Regards Christel


#3

Christel Very interesting, but could you tell me, what do you
mean by the abbreviation LPG?

Kind regards
Niels L=F8vschal, Jyllinge, Denmark
@L_F8vschal
phone (+45) 46 78 89 94


#4

Hello Christel.

I have been using flashback arrestors on my torches for about
two years now. Like you, I was unaware of them for many years.

The welding supply where I obtain my oxygen and other supplies
let me borrow a video on torch safety. This video convinced me to
install flashback arrestors.

When using large melting tips they are even more important as
tank pressure can drop fast.

I do not know of any regulations requiring them here in
California, U.S.A.

Thank you for reminding me to check my arrestors. They should be
tested every six months.

Timothy A. Hansen
@Timothy_A_Hansen
http://home.earthlink.net/~tahhandcraft


#5

Oh yes, I’ve known about them for years, and bought them for my
tanks when I bought this torch set up 5 (?) years ago. Wouldn’t
consider using tanks without them, and I use much smaller tanks
than most of you.

Elaine
Chicago
US


#6

Absolutely you need a flashback arrester. Many torch units have
them built into the torch or sometimes the regulator. But the
principle is the same: prevent the flame from travelling back to
the gas. For a few extra dollars your safety is well worth it.

Cheers

Virginia Lyons


#7

Christel I live in Washington State, USA and have had flashback
arrestors on my tanks for 15+ years. I don’t know if it is a
requirement here (I think I will check) but was advised to
install them because of the potential dangers. To my mind the
small cost (less than $5 each) was well worth it. I always
recommend it to my students.

Lorri


#8

I was wondering if anyone who is familiar with Prest-o-lites knows
if I should use flashback arrestors with my B tank. And if so, are
there specific ones for different torch models or they all a generic
size that will fit on any torch?


#9

Corinne: I was told by my very first instructor to definitely have
a flashback arrestor. I bought mine where I bought my tank. But I
would think you could find them at most any welding shop. There is a
choice, I think, as to how you mount it. I have mine mounted
directly below the torch, but lots of people have theirs positioned
at the tank instead of the torch. If you put it right at the torch,
it takes a little practice to adjust to the extra weight, but it has
never bothered me. Since I had mine put on when I first bought my
torch, I adjusted to it right away. Check it out.

Kay


#10

Kay,

The flashback arrestor should be at the regulator. The hose is a
vulnerable weakness.

Mark


#11

Hi Corinne,

I just bought a flashback arrestor for my B tank. I bought mine from
a welding supply company and they sold them in pairs one for oxygen
and one for acetylene. I only need the acetylene arrestor for my B
tank. Apparently it did not matter what torch I was using - the
consideration was the size of the connection to the tank.