Using brass post valves/ anthing wrong with this setup?

kimsey0000 · 6th October 2007, 21:32

Hi all,
Much as i love these little bernzomatic cans, they're great for testing, they're just not practical for where i live, i'm going for a new setup. The short duration isn't the only thing that bothers me, half of what bothers me is the ammount of rust on the valve at every single hardware store in the 30741 area i go to, lol. My questions to you knowledgeable rebreather guru types that might read this are:
Is there anything wrong with using the CGA 540 solid brass post valves, like the ones on welding tanks? I'm not sure about the way the exterior brass corrosion/patina would react with o2, (if at all). I'm not actually considering using using a welding tank mind you, catalina makes a baked on paint aluminum tank with the aformentioned brass post valves. The regulator i was considering using in my setup was one of these mil-spec chemetrons:
CHEMETRON~Medical Oxygen Regulator~15 LPM~CGA540~NEW - (eBay item 260165228648 end time Oct-07-07 18:11:20 PDT)

Yes, none of this stuff was designed for underwater use, but i imagine the design many of the rebreathers from the 30's 40's 50's etc weren't based on underwater... what would you call it? Pnumatic systems?
Just for the record, the rebreather i created is a design based on one of Christian J. Lambertsen's, (circa 1939-1945) following his patent prints. It's been working good so far... (it's as close to the original as i could get, lol)

Replies very much appreaciated, thanks for checking this post out.

Captain Randy · 6th October 2007, 23:54

Other than removing/changing gauges I can't see why it wouldn't work as a non compensated first stage. Unless you just really like the welding post I would adapt it to din, Global sells a din to 1/4" npt fill adapter that would allow you to use scuba tanks.

Randy

kimsey0000 · 7th October 2007, 10:21

Thanks for the reply Randy. The brass 540 connections are definately going to stay unless they won't work - it's just too practical not to (under my circumstances) As for the gauges... why exactly? Please explain... unless i'm missing something here, all gauges are airtight (watertight). Or are you thinking in terms of inaccurate readings due to the 13 psi of pressure up against them, or...?

Captain Randy · 7th October 2007, 11:54

Quote: (Originally Posted by kimsey0000)

Thanks for the reply Randy. The brass 540 connections are definately going to stay unless they won't work - it's just too practical not to (under my circumstances) As for the gauges... why exactly? Please explain... unless i'm missing something here, all gauges are airtight (watertight). Or are you thinking in terms of inaccurate readings due to the 13 psi of pressure up against them, or...?

The gauges don't look oil filled and the water will probably flex it enough to cause a leak

Randy

hoppyinca · 7th October 2007, 21:43

Quote: (Originally Posted by Captain Randy)

The gauges don't look oil filled and the water will probably flex it enough to cause a leak

Randy

or the plastic covers could be distorted by the pressure and prevent proper indication... think the plastic scuba gages at deeper depths...

hoppy

kimsey0000 · 7th October 2007, 22:48

Thanks for the input so far guys. Looks like a gaugeless oxy reg is in order... I honestly couldn't say what size threads the gauges that are standard with welding regs are, but it doubt they're the same size as a hp diving SPG. Now that would be one heck of a coincedence if they were! Kind of wish i hadn't given away my oxy-acetylene rig years ago... would have been useful to dissect the o2 reg, examine the guts a bit... get thread sizes etc... and whatever else one would want to look at for a project like this...

6th October 2007, 21:32	#1 (permalink)
kimsey0000 New Member Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: Sep 2007 Location: Rossville Georgia Posts: 4	Using brass post valves/ anthing wrong with this setup? Hi all, Much as i love these little bernzomatic cans, they're great for testing, they're just not practical for where i live, i'm going for a new setup. The short duration isn't the only thing that bothers me, half of what bothers me is the ammount of rust on the valve at every single hardware store in the 30741 area i go to, lol. My questions to you knowledgeable rebreather guru types that might read this are: Is there anything wrong with using the CGA 540 solid brass post valves, like the ones on welding tanks? I'm not sure about the way the exterior brass corrosion/patina would react with o2, (if at all). I'm not actually considering using using a welding tank mind you, catalina makes a baked on paint aluminum tank with the aformentioned brass post valves. The regulator i was considering using in my setup was one of these mil-spec chemetrons: CHEMETRON~Medical Oxygen Regulator~15 LPM~CGA540~NEW - (eBay item 260165228648 end time Oct-07-07 18:11:20 PDT) Yes, none of this stuff was designed for underwater use, but i imagine the design many of the rebreathers from the 30's 40's 50's etc weren't based on underwater... what would you call it? Pnumatic systems? Just for the record, the rebreather i created is a design based on one of Christian J. Lambertsen's, (circa 1939-1945) following his patent prints. It's been working good so far... (it's as close to the original as i could get, lol) Replies very much appreaciated, thanks for checking this post out.
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6th October 2007, 23:54	#2 (permalink)
Captain Randy New Member Current Rebreather/s: Dolphin Ray Other Rebreather/s: Dolphin Ray Join Date: Dec 2005 Location: Houston, Texas Posts: 45	Re: Using brass post valves/ anthing wrong with this setup? Other than removing/changing gauges I can't see why it wouldn't work as a non compensated first stage. Unless you just really like the welding post I would adapt it to din, Global sells a din to 1/4" npt fill adapter that would allow you to use scuba tanks. Randy
(Offline)

7th October 2007, 10:21	#3 (permalink)
kimsey0000 New Member Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: Sep 2007 Location: Rossville Georgia Posts: 4	Re: Using brass post valves/ anthing wrong with this setup? Thanks for the reply Randy. The brass 540 connections are definately going to stay unless they won't work - it's just too practical not to (under my circumstances) As for the gauges... why exactly? Please explain... unless i'm missing something here, all gauges are airtight (watertight). Or are you thinking in terms of inaccurate readings due to the 13 psi of pressure up against them, or...?
(Offline)

7th October 2007, 11:54	#4 (permalink)
Captain Randy New Member Current Rebreather/s: Dolphin Ray Other Rebreather/s: Dolphin Ray Join Date: Dec 2005 Location: Houston, Texas Posts: 45	Re: Using brass post valves/ anthing wrong with this setup? Quote: (Originally Posted by kimsey0000) Thanks for the reply Randy. The brass 540 connections are definately going to stay unless they won't work - it's just too practical not to (under my circumstances) As for the gauges... why exactly? Please explain... unless i'm missing something here, all gauges are airtight (watertight). Or are you thinking in terms of inaccurate readings due to the 13 psi of pressure up against them, or...? The gauges don't look oil filled and the water will probably flex it enough to cause a leak Randy
(Offline)

7th October 2007, 21:43	#5 (permalink)
hoppyinca New Member Current Rebreather/s: MK 15.X Other Rebreather/s: Join Date: Jun 2005 Location: Laguna Niguel, CA USA Posts: 252	Re: Using brass post valves/ anthing wrong with this setup? Quote: (Originally Posted by Captain Randy) The gauges don't look oil filled and the water will probably flex it enough to cause a leak Randy or the plastic covers could be distorted by the pressure and prevent proper indication... think the plastic scuba gages at deeper depths... hoppy
(Offline)

7th October 2007, 22:48	#6 (permalink)
kimsey0000 New Member Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: Sep 2007 Location: Rossville Georgia Posts: 4	Re: Using brass post valves/ anthing wrong with this setup? Thanks for the input so far guys. Looks like a gaugeless oxy reg is in order... I honestly couldn't say what size threads the gauges that are standard with welding regs are, but it doubt they're the same size as a hp diving SPG. Now that would be one heck of a coincedence if they were! Kind of wish i hadn't given away my oxy-acetylene rig years ago... would have been useful to dissect the o2 reg, examine the guts a bit... get thread sizes etc... and whatever else one would want to look at for a project like this...
(Offline)

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