My first big tev kicked my butt.

[ksefan]

First I found that the brazing tip on my torch kit was too small to unbraze the old txv. I drive 45 minutes for a rosebud tip. Then after many failed attempts to braze the new valve I ran out of n2 and acetylene. Used 3 full bottles of each, the big rosebud used a mc bottle in about 5 minutes. After waiting 90 minutes for the on call guy to help with more gas and more experience, we called it a day at 10:30 pm and it still leaks. I thought it was going to be just another easy txv day. Got home after the 2 hour drive about 12:30 and back this morning at 6 on a different job, I wanted to fix it myself.

[ksefan]

3rd pic upside down, oops.

[pecmsg]

Valves that large I completely disassemble then braze.

Wet rags and thermos block doesn't cut it.

[crazzycajun]

Valves that large I completely disassemble then braze.

Wet rags and thermos block doesn't cut it.

or just rebuild the valve

[kdean1]

Yeah, there's a lot of mass to heat up to braze those. They are a challenge.
Good for you on staying with it to finish it.

[pecmsg]

or just rebuild the valve

Had to do that on a Carrier Chiller. Much easier then all the Burn Permit BS!

[71CHOPS]

You likely have your gas pressures turned up too high. A rosebud tip doesn’t require any more gas than a standard tip. Set your pressures at 7/7 and adjust from there, if necessary. I braze 130 ton TXV’s at those pressures.

Use heat paste around the body and wrap in wet rags. Braze one side, pour water on to cool, then braze the other.

Make sure to clean everything as well as possible, and use flux on the fittings you unbrazed. Sometimes I will cut the old inlet side piping braze joint off, so I have fresh copper.

[coolerik]

The best is when the distributor tubes start popping out! Gah!!


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[ksefan]

Thanks for the advice, the next one will be better.

[71CHOPS]

The best is when the distributor tubes start popping out! Gah!!


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I fill them with heat paste and rags!

[71CHOPS]

Thanks for the advice, the next one will be better.

Get some scrap and practice with the rosebud. Once you get used to it, you’ll prolly only use that.

[timebuilder]

I wrap the distributor tube assembly with a rag just to keep those from popping out.

Sometimes...before I go to install the valve....I will braze on a copper stub with the stub facing up and the tip pointed away from the valve, and then use a coupler with the valve all wrapped up to be able to braze the other end of the stub to the assembly....that way I don't have that much mass drawing away heat from the final connection.

[Lddc]

Replacing the TXV on a brand new unit? Wonderful carrier quality control. They likely over heated it in the factory. Good job staying on it though.

[Lahrs]

Sometimes...before I go to install the valve....I will braze on a copper stub with the stub facing up and the tip pointed away from the valve, and then use a coupler with the valve all wrapped up to be able to braze the other end of the stub to the assembly....that way I don't have that much mass drawing away heat from the final connection.

This is exactly what I also do. Not only does it make your job easier, but the next person's also. I don't think I've done a direct TXV to distributor in 25 years, mine would be ugly if tried at this point.

[servicefitter]

You all work to hard! Buy a new distributor, tubing and couplings. First solder 12" tubes in distributor and couplings then the valve all on a pipe vise in the comfort of being on the ground not standing on your head and a stub on the liquid side. Imp cut all the dist tubes and liquid. For some reason it's easier to solder up 3/8 tubes than the whole dist. Your head won't hurt as bad or your body and save time.

[gravity]

Should have used staybright8


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[Brian8383]

Great advice here. One more I'll add is wet rags will dry out on some of the bigger jobs before you finish. I keep a spray bottle full of water and spray the rag down occasionally while I have the heat on the joint. Even if the outside of the rag is still kind of wet, where the rag hits the metal will dry out first.

[Brian8383]

I wrap the distributor tube assembly with a rag just to keep those from popping out.

Sometimes...before I go to install the valve....I will braze on a copper stub with the stub facing up and the tip pointed away from the valve, and then use a coupler with the valve all wrapped up to be able to braze the other end of the stub to the assembly....that way I don't have that much mass drawing away heat from the final connection.

I'll usually do this also. An extra inch or two matters.
(Insert joke here).