I was working on a refrigeration system recently, and between silver
brazing and purging we used up 2 plus small bottles of nitrogen. Still
had some silver brazing to do and I just didn't want to run back to the
store for a refill again. Its only $10 (plus some fee or other, plus
hazmat) for still less than $20, but its a pain. I did a little
research and I couldn't find any reason not to use Argon, and I have a
tall bottle of Argon. Using the same flow rate from the argon bottle
the high pressure needle has barely moved. Sure it cost a lot more to
fill that tall bottle with more expensive gas, but I can still take it
back in the shop and weld all day with it (depending on what I am doing).

All the nitrogen/argon does is purge the system and prevent oxidation
inside the copper lines when silver brazing. Either way still have to
pull 500 microns or better before calling my refrigeration guy to refill
the system.

Hazmat for relatively low pressure nitrogen? really?

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 7/1/2020 7:42 PM, Bob La Londe wrote:

I was working on a refrigeration system recently, and between silver
brazing and purging we used up 2 plus small bottles of nitrogen.  Still
had some silver brazing to do and I just didn't want to run back to the
store for a refill again.  Its only $10 (plus some fee or other, plus hazmat) for still less than $20, but its a pain.  I did a little
research and I couldn't find any reason not to use Argon, and I have a
tall bottle of Argon.  Using the same flow rate from the argon bottle
the high pressure needle has barely moved.  Sure it cost a lot more to
fill that tall bottle with more expensive gas, but I can still take it
back in the shop and weld all day with it (depending on what I am doing).

All the nitrogen/argon does is purge the system and prevent oxidation
inside the copper lines when silver brazing.  Either way still have to
pull 500 microns or better before calling my refrigeration guy to refill
the system.

Hazmat for relatively low pressure nitrogen?  really?

You are indeed getting ripped off!
I looked at a bunch of invoices from last year for medical grade
nitrogen in tanks from NORCO. Never a mention of HASMAT charges.

We used the nitrogen in the selective soldering machine. NORCO delivered
the new tanks and picked up the old ones. There was only a delivery charge.

Paul

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 02/07/2020 03:42, Bob La Londe wrote:

I was working on a refrigeration system recently, and between silver
brazing and purging we used up 2 plus small bottles of nitrogen. Still
had some silver brazing to do and I just didn't want to run back to
the store for a refill again.  Its only $10 (plus some fee or other,
plus hazmat) for still less than $20, but its a pain.  I did a little research and I couldn't find any reason not to use Argon, and I have a
tall bottle of Argon.  Using the same flow rate from the argon bottle
the high pressure needle has barely moved.  Sure it cost a lot more to
fill that tall bottle with more expensive gas, but I can still take it
back in the shop and weld all day with it (depending on what I am doing).

All the nitrogen/argon does is purge the system and prevent oxidation
inside the copper lines when silver brazing.  Either way still have to
pull 500 microns or better before calling my refrigeration guy to
refill the system.

Hazmat for relatively low pressure nitrogen?  really?

When you say silver brazing what are you using out of curiosity, in the
UK for copper to copper HVAC work silphos rod is used which doesn't
require flux for copper to copper. Comes in various alloys and one local welding guy sells it by the stick to HVAC guys as they need very little
for a joint and it goes a long way  and getting a whole tube of rods is expensive.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 7/2/2020 4:17 PM, David Billington wrote:

On 02/07/2020 03:42, Bob La Londe wrote:

I was working on a refrigeration system recently, and between silver
brazing and purging we used up 2 plus small bottles of nitrogen. Still
had some silver brazing to do and I just didn't want to run back to
the store for a refill again.  Its only $10 (plus some fee or other,
plus hazmat) for still less than $20, but its a pain.  I did a little
research and I couldn't find any reason not to use Argon, and I have a
tall bottle of Argon.  Using the same flow rate from the argon bottle
the high pressure needle has barely moved.  Sure it cost a lot more to
fill that tall bottle with more expensive gas, but I can still take it
back in the shop and weld all day with it (depending on what I am doing).

All the nitrogen/argon does is purge the system and prevent oxidation
inside the copper lines when silver brazing.  Either way still have to
pull 500 microns or better before calling my refrigeration guy to
refill the system.

Hazmat for relatively low pressure nitrogen?  really?

When you say silver brazing what are you using out of curiosity, in the
UK for copper to copper HVAC work silphos rod is used which doesn't
require flux for copper to copper. Comes in various alloys and one local welding guy sells it by the stick to HVAC guys as they need very little
for a joint and it goes a long way  and getting a whole tube of rods is expensive.

Silphos. 15/5/80. Yes self fluxing. Does not prevent oxidation on the
inside of the lines from heat. Inert gas is needed for that.

Sometimes the difference between "brazing" and soldering is defined as
at above or below a certain temperature threshold. Silphos silver
brazing is right at that threshold.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On Wed, 1 Jul 2020 19:42:09 -0700, Bob La Londe <none@none.com99>
wrote:

I was working on a refrigeration system recently, and between silver
brazing and purging we used up 2 plus small bottles of nitrogen. Still
had some silver brazing to do and I just didn't want to run back to the
store for a refill again. Its only $10 (plus some fee or other, plus
hazmat) for still less than $20, but its a pain. I did a little
research and I couldn't find any reason not to use Argon, and I have a
tall bottle of Argon. Using the same flow rate from the argon bottle
the high pressure needle has barely moved. Sure it cost a lot more to
fill that tall bottle with more expensive gas, but I can still take it
back in the shop and weld all day with it (depending on what I am doing).

All the nitrogen/argon does is purge the system and prevent oxidation
inside the copper lines when silver brazing. Either way still have to
pull 500 microns or better before calling my refrigeration guy to refill
the system.

Hazmat for relatively low pressure nitrogen? really?

Allentown, PA. USA. All the welding joints around here tack on a
hazmat fee and a doc fee. Totally BS.

Get a large N2 tank, probably cost you $15 to fill it.

Your high price is because it's a small tank, always a premium to fill
those.

Maybe look into a medium size tank, the 300's are a pain to move
around.

Randy
Remove 333 to reply.
Randy

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)