LEARN AND. . . RE-LEARN SOMETHING ALMOST EVERY DAY!

[gtt]

MISTAKE MADE BUT FIXED, SEE THE ATTACHMENT!

[jpsmith1cm]

While I carry a tube of the stuff, I rarely use it.

A good, wet rag will usually do the same thing. I keep the thermotrap for VERY tight spots.

I think that we have all done that once...





..... or twice.

[joemach]

As soon as I saw the first picture I could feel your pain.

I would say that is one of the most horrible feelings a tech can have. All the pride you feel after sweating in a new TXV only to find the distributor tubes are no longer connected to the evap coil. Suddenly you just hate yourself. How the heck am I going to fix that?

One trick I was taught and has worked out pretty good so far has been to just replace the guts & power head of the TXV instead of the whole thing. This is assuming you can find the exact same valve. Then you can eliminate this from happening. Sometimes you can hardly get a torch into some cooler or freezer coils to get the TXV out.

Although lots of heat sink will work if you use it.

[derbysr]

Dont feel bad, just last week i had put in 2nd valve in after i burnt the 1st one .The tip i was brazing with , the hole was to big where the flame came out , becuase i cleaned to good. I burnt a hole on the last tube 5/8 i was brazing . Got it "too HOT" .Had plenty of Thermo-Trap + wet rags .
Solved that problem by getting a new # 2 tip , and everthingh else fell into place .
This mistake cost "me" ......time + parts .
The learning experience I will not trade it for anythingh in this world.
We are humans bound by our own .............fill in the blank yourselves. Going to keep this attachment to remind myself of it....................

[Tool-Slinger]

I have recently replaced some 30 ton txv's they have about ten 1/4 inch feeder tubes coming out of the distributor. They are a real PITA even for two guys with oxy/acet torches. They must weigh over a pound. I burned up one txv in the process. I quit using the thermotrap, in favor of wet rags and a sprayer bottle handy. I will never use thermotrap again. It has a 'time-limit' and it turns to crud, plus it is an obstruction to solder on anything it touches. An Anti-flux, if you mistakenly get where you need to solder. I used to keep some on my truck like it was some sort of 'secret-weapon' I could use in a really tough job, but I have no further use for it at all. Snake-oil.

Like joemach, I just replace the power-head itself if there is any perfect match replacement. That does work most of the time, powerhead just looses charge and it closes off the valve.

[gtt]

Thanks for the encouraging words!

I still have the old txv and will dissassemble to familiarize with the changing of the teeny-tiny springs and such, and the power head.

When I worked in the factory testing units, we'd frequently have bad TXV's and solenoid valves come thru, and changing the "guts" was the first thing done before replacing the whole body. The circuits on those large dehumidifiers usually had an isolation valve, so very easy to pump down to 25-30psig and pull the guts and swap 'em before losing the positive pressure completely. But, with a small roof top, not so fortunate!

I should've had a spray bottle that day, got one NOW!! I even picked up some SPRAY ON Thermotrap. It is messy, but, will continue to use it and the wet rags, a little gun shy, eh? !!

Later this same week I had to change another TXV in split system. It was a 7 1/2 ton with 8 or so tubes. DID NOT MELT THAT ONE!! Getting the 5/8" copper off of the brass distributor piece was not pretty. Ended up twisting the body of the TXV completely off the copper tubing and then heated the stub remaining red hot and got it off the brass body.

[thump_rrr]

When removing TX valves a turbo torch is far superior to oxy-acetylene.
The flame is much bigger so you can heat up the whole area quicker and the flame is not as hot.

To install TX valves I use the oxy-acetylene.

I have also started to replace old TX valves with take apart valves such as these.
http://www.emersonclimate.com/flowco...Take-Apart.pdf

[gtt]

Thanks for the suggestions!

Always something different to learn it seems.