Date: Fri, 30 Apr 2010 11:27:55 -0700
Reply-To: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: Todd <dafydd3r**At_Symbol_Here**YAHOO.COM>
Subject: Re: Gas Regulator Question
In-Reply-To: <OF23065A42.319DA0A9-ON85257715.005246F0-85257715.0052B770**At_Symbol_Here**sealedair.com>
Hi Folks,

Certainly there are cases with Oxygen where fires (or extreme heat) have be
en created by adiabatic compression when opening a valve or regulator too f
ast. When the user opens the cylinder valve rapidly, the regulator can melt
, blow a hole in itself, or can otherwise fail.  This could still happen if
 a regulator is improperly equipped with a ball valve on the outlet or just
 opened too fast.  Regulators are made as precision instruments, but abuse,
 overpressurization, and opening valves too fast can compromise their safe 
operation.

There have been also instances where older torches allow acetylene to bleed
 back into the oxygen lines, or vice versa, and once a mixture is reached t
hat falls between the LEL and UEL for that enriched oxygen mix... bang.

If regulators and torches are kept in good repair, valves are opened slowly
, equipment is vented and regulators removed when work is completed - every
 time - there shouldn't be any trouble.

I would agree that standing to the side can be a good idea not only because
 of the inherent dangers, but also because any material that ends up in an 
open valve, or in an open-ended hose, can get shot out by the pressure behi
nd it when the valve/regulator gets opened.

I reccommend choosing appropriate PPE for handling cylinders, including but
 not limited to safety glasses and leather gloves, with steel toe shoes if 
moving cylinders. I see nothing wrong with averting one's face, in general,
 if otherwise working safely with appropriate PPE and procedures.

BTW: Keeping cylinder caps on cylinders in use (for those cylinders that ha
ve threads for a cap) is something OSHA likes to check.. And an easy violat
ion if they find uncapped cylinders.

Larry - you can rely at the folks at Airgas National Welders, I know their 
Safety Directors and they're some good folks - Hospitable, helpful, and kno
wledgeable.

Todd Perkins
Safety Director
Airgas Mid America

--- On Fri, 4/30/10, Larry.Freyer**At_Symbol_Here**SEALEDAIR.COM  wrote:

> From: Larry.Freyer**At_Symbol_Here**SEALEDAIR.COM 
> Subject: Re: [DCHAS-L] Gas Regulator Question
> To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
> Date: Friday, April 30, 2010, 10:03 AM
> In our last training class, conducted
> by Airgas National Welders, the
> trainer pointed out that you should not stand in front of
> the regulator
> when opening a gas cylinder.=C2=A0 This was the first time
> that I had seen it
> listed as a specific issue but it makes a lot of sense,
> 
> Larry
> 
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> 
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 Long ago, when I
> was taking welding lessons, the instructor
> taught us to avert our faces from the regulator gauges when
> opening a gas
> tank because of a possible defect in the regulator that
> would pressurize
> the gauge and explode the glass.
> 
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 Since that time,
> I have read several books on laboratory
> practices and do not recall any of them alluding to the
> practice of
> averting one=E2=80=99s face when opening a gas cylinder.=C2=A0
> Should they?
> 
> With all the accumulated experience in this group, has
> anyone heard of this
> practice or hazard?
> 
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 (Note: My old
> instructor might have been confusing a defective
> regulator hazard with the one resulting from using a
> contaminated regulator
> with an oxygen cylinder.)
> 
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 Thank you very
> much,
> 
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 Ben
> 

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