Corroded brazed joint to an R-22 heat pump:

http://67.207.131.7/poolheater.jpg

Doesn't look to me like this has enough sound material left to be spliced
back together with a new braze.

Is there any good way to put a new fitting into the side of these
hermetically sealed compressor cans?

"Richard J Kinch" wrote in message
...
Corroded brazed joint to an R-22 heat pump:

http://67.207.131.7/poolheater.jpg

Doesn't look to me like this has enough sound material left to be spliced
back together with a new braze.

Is there any good way to put a new fitting into the side of these
hermetically sealed compressor cans?

I think you could sneak a coupler on that little stub. Time to collect one
of those many favors God owes you!

On Tue, 09 Jun 2009 23:09:52 -0500, Richard J Kinch
wrote:

Corroded brazed joint to an R-22 heat pump:

http://67.207.131.7/poolheater.jpg

Doesn't look to me like this has enough sound material left to be spliced
back together with a new braze.

Is there any good way to put a new fitting into the side of these
hermetically sealed compressor cans?

There might be enough meat left to work with, but you need to be
gentle with it - don't even THINK about swaging on the compressor
stub, if it splits you are dead.

You need to cut off the steel where it's swaged out to let the
Copper go inside. Clean up and "tin" with silver braze, then put a
larger piece of tubing over the top of steel line and braze it. Use a
swage on the copper tubing if needed to get the right size.

Either that, or get the next size smaller tubing and go inside what's
left of the old nipple. Don't worry about restriction, it works.

-- Bruce --

Richard J Kinch fired this volley in
:

Doesn't look to me like this has enough sound material left to be
spliced back together with a new braze.

Is there any good way to put a new fitting into the side of these
hermetically sealed compressor cans?

Richard, it looks to me like there's enough to do it wrong twice, and
still have enough for a good fix.

You can mount a nipple in a small backer plate, then weld that to the
can, but I don't like to introduce that much heat on the can itself.
Oil, paint, insulating coatings, etc. on the inside may char and end
up blocking a valve downline.

LLoyd

On Tue, 09 Jun 2009 23:09:52 -0500, Richard J Kinch
wrote:

Corroded brazed joint to an R-22 heat pump:

http://67.207.131.7/poolheater.jpg

Doesn't look to me like this has enough sound material left to be spliced
back together with a new braze.

Is there any good way to put a new fitting into the side of these
hermetically sealed compressor cans?

I just had another thought that requires a seperate post - Looks like
you lost some oil when it rusted through. You don't want to waste
several hours getting that system all fixed up, only to have the
compressor sieze on you.

Cut loose both the suction and discharge, and one of the blanked off
process tubes on the side of the can will let you dump the oil out of
the compressor crankcase when you pop it open.

Find a Cut Sheet for the compressor online, they will tell you how
much oil it takes and show an internal diagram and what each tube is
used for. Sometimes they are just alternate suction inlets depending
on system layout - and you might be able to switch over to it...

Some low temperature refrigeration compressors have a loop of tubing
in the crankcase for an oil cooler, and all you'll get is to the other
end of the tube.

Drain the old oil - measure for reference. And if the amount that
comes out is way short, you just saved yourself...

Braze an access valve on that process tube for future use, and braze
the compressor back into the system.

Then get a refrigeration oil hand pump (looks like a miniature
bicycle pump with 1/4" Flare fittings) and a bottle of the right type
(Mineral, PAG, POE depending on the refrigerant) and weight
refrigeration oil, and put in a fresh oil charge.

You can find the oil in quarts so you don't have to get a gallon AKA
Lifetime Supply. The pumps are usually calibrated at so many ounces
per stroke - RTFM. (Yellow Jacket 77930 is 3.8 oz., 77940 is 2.6 oz.)

There might be some old oil still running around in the lines and
coils, but that's okay. A little too much oil in the system is a
whole lot better than not enough.

A lot too much is bad, but you would really have to work at
overfilling it that much.

-- Bruce --

Bruce L. Bergman wrote:

Is there any good way to put a new fitting into the side of these
hermetically sealed compressor cans?

I just had another thought that requires a seperate post - Looks like
you lost some oil when it rusted through. You don't want to waste
several hours getting that system all fixed up, only to have the
compressor sieze on you.

Bruce, what is your line of work? One moment I think you are HVAC, the next moment I
think you are an electrician. You are a wealth of knowledge.

Wes

Bruce L. Bergman writes:

You don't want to waste
several hours getting that system all fixed up, only to have the
compressor sieze on you.

Good point, although my experience with suction side leaks is that not much
oil is lost, just enough to see.

But now I also wonder how long this system has been open and whether
moisture hasn't gotten in.

On Wed, 10 Jun 2009 18:11:58 -0400, Wes wrote:

Bruce L. Bergman wrote:

Is there any good way to put a new fitting into the side of these
hermetically sealed compressor cans?

I just had another thought that requires a seperate post - Looks like
you lost some oil when it rusted through. You don't want to waste
several hours getting that system all fixed up, only to have the
compressor sieze on you.

Bruce, what is your line of work? One moment I think you are HVAC, the next moment I
think you are an electrician. You are a wealth of knowledge.

Wes

Now, Electrican. Before that, General Construction and I brushed up
on my Framing and Plumbing. Two jobs ago, Heating and Air. Oh, and
before that Central Office Equipment installer (Step and Digital and
Power) and Construction Cable Splicer.

And when other crafts are around, I tend to pay attention. ;-) You
can pick up a lot through careful observation.

Sometimes it is nice to know lots about lots.

And you learn what NOT to do, which is far more important some days.
Like mess with old single-wrap paper insulated telephone cable more
than absolutely necessary - there's a real good reason it's called
"Firecracker Cable". Open up the splice to fix one short or cross and
cause ten more...

The wise man says "mark that one pair bad and be done with it". But
the fool wastes a lot of effort trying to fix the un-fixable, and ends
up three steps back from where he started - with a bunch of angry
customers with dead phone lines, to boot.

-- Bruce --

On Wed, 10 Jun 2009 19:07:25 -0500, Richard J Kinch
wrote:

Bruce L. Bergman writes:

You don't want to waste
several hours getting that system all fixed up, only to have the
compressor sieze on you.

Good point, although my experience with suction side leaks is that not much
oil is lost, just enough to see.

But now I also wonder how long this system has been open and whether
moisture hasn't gotten in.

Well, to be safe put in a suction side filter-drier, the big one
that holds lots of moisture. For real insurance, a liquid side
filter-drier, too - if the compressor grenades on you it'll keep the
fragments out of the condenser.

And draw it down to a hard vacuum and leave it there a few hours
before recharging - the moisture gets trapped in the oil and it takes
quite a while to get it all out.

(With a two stage oil-ballast vacuum pump. Those toy air-venturi
pumps aren't worth the effort to throw them in the dumpster.)

A sight glass with the pink/blue indicator dot might be a real good
idea to weld in, too - if you see it switch to blue, you know it got
soaked and it's time to evacuate and replace the driers again

If it's working well but comes up "Wet" after a few days, it might
be worth the effort to install one of those huge STAS filter shells
they use at supermarkets when they get mass quantities of water
inside. No brazing, you unbolt and open the end of the filter shell
and change the element and the gasket.

The single-size should be plenty - they make some that stack three
or four elements in parallel.

-- Bruce --

Well, now here is an update where the owner has cleaned off the corrosion,
showing some sound remnant metal, with the joint being apparently copper to
copper:

http://67.207.131.7/poolheater2.jpg

Here is an idea I had: could one not just wrap this snug with flat copper
braid (like copper grounding strap stuff) and then fill with braze, like a
solid metal "bandage"? Or even wrap with copper wire and fill?

Otherwise I am thinking a sleeve machined to fit closely over the remnant
geometry.

In any case, brazing will require opening this joint, cleaning off the oil
residue, reassembling with repair parts, filling with inert gas, and
finally heating to braze temp. Then evacuation and recharging.

On Thu, 11 Jun 2009 15:19:37 -0500, Richard J Kinch
wrote:

Well, now here is an update where the owner has cleaned off the corrosion,
showing some sound remnant metal, with the joint being apparently copper to
copper:

http://67.207.131.7/poolheater2.jpg

Here is an idea I had: could one not just wrap this snug with flat copper
braid (like copper grounding strap stuff) and then fill with braze, like a
solid metal "bandage"? Or even wrap with copper wire and fill?

Otherwise I am thinking a sleeve machined to fit closely over the remnant
geometry.

In any case, brazing will require opening this joint, cleaning off the oil
residue, reassembling with repair parts, filling with inert gas, and
finally heating to braze temp. Then evacuation and recharging.

Pressurize and get out the test soap - figure out exactly where it
is leaking. You do NOT necessarily have to take the old joint apart
if it's basically sound.

If it is a cold braze joint and a channel opened up in the gap after
time passed - take it apart, clean it up, and re-braze it.

If it is a leak in the stub and not a bad joint braze, and I was
making a patch for this, I'd just slit a section of copper tubing and
slide it over the leak Put the copper wire wind layer over the patch
to mechanically hold it, then braze it in place.

-- Bruce --