4 way reversing valve question

[Rmorales]

I was just reading in my school book that when installing a 4 way valve it should not be subject to excessive heat.

I was presented a question stating when brazing a 4 way reversing valve heat absorbing paste should be placed around the body of the valve to minimize the chance of internal damage to the valve.

Book doesnt clearly indicate if this is a fact or bull poo. A little help would be great.

[Texas-Tech]

A lot of guys use the paste, never have myself. They make a fork shaped tool for the torch that will allow you to heat all three pipes at one time to minimize the heating time needed to remove the valve.

You can also use tubing cutters to remove the old one and then just fit the new valve in place. If you unsweat the valve be ready for an unpleasant experience with the phosgene gas you'll encounter.

[Rmorales]

I am guessing according to your statement that this can be a true statement. If the valve is heated with no protection there is a chance that the internal components can be damaged.

[maintenanceguy]

You should do something to protect the valve:

Use the paste you're talking about
wrap the valve with a rag
use a lot of heat so you can braze really fast.

Any of the above works, a combination of 2 is even better.

[themetalhead]

alot of guys will use 45% rod instead of 15 so they don't need as much heat, it's more expensive though.

[SoFlaDave]

There are teflon seals and seats inside that can be damaged if they get too hot.

I usually unsweat the discharge line and cut the other 3 at the easiest spot where I can add couplings and remove the whole assembly and mark the positions of the pipes before unsweating them from the valve itself. If i cant get a tubing cutter in there I have no problem taking them off with a sawzall, cut flush with the joints and use reducer couplings to go into the new valve.

Sweat the stubs into the new valve one at a time with a wet rag to keep it cool and then reconnect the piping with couplings.

[HVAC-matt]

There are teflon seals and seats inside that can be damaged if they get too hot.

I usually unsweat the discharge line and cut the other 3 at the easiest spot where I can add couplings and remove the whole assembly and mark the positions of the pipes before unsweating them from the valve itself. If i cant get a tubing cutter in there I have no problem taking them off with a sawzall, cut flush with the joints and use reducer couplings to go into the new valve.

Sweat the stubs into the new valve one at a time with a wet rag to keep it cool and then reconnect the piping with couplings.

SoFladave your not worried about any metal shavings getting inside the lines by using a sawzall. Just wondering??

[Joe Harper]

A while back a member posted pictures of how to change the valve using stubs and such. I think he submerged the valve in water (I know it doesn't sound logical) and brazed his stubs on. He might of used wet rags. Might be worth running a search.

[karsthuntr]

SoFladave your not worried about any metal shavings getting inside the lines by using a sawzall. Just wondering??

The discharge line is on the bottom, unsweat that and cap the line going to the compressor. Cut the other three, the shavings will fall into the valve your taking out, its already bad whats it gonna hurt.

[HVAC-matt]

The discharge line is on the bottom, unsweat that and cap the line going to the compressor. Cut the other three, the shavings will fall into the valve your taking out, its already bad whats it gonna hurt.

Ok I was just wondering bc in school they had told us never to use a sawzall or hack saw. Makes sense thanks.

[hvacpope]

If you unsweat the valve be ready for an unpleasant experience with the phosgene gas you'll encounter.

I thought we were beyond that point!!brazing/un-brazing etc does not generates any phosgene gas, another old wives tale.

[SoFlaDave]

Whatever the compound thats produced when refrigerant passes through a flame actually is, its extremely unpleasant at best.

[SoFlaDave]

Ok I was just wondering bc in school they had told us never to use a sawzall or hack saw. Makes sense thanks.

Basically, if it can be done with tubing cutters, by all means thats the best way. Sometimes you gotta do what you gotta do though.

[m8j4c]

If you're changing out the valve I would sawzall the top 3 lines at the bad reversing valve body so that you have the female side of the reversing valve connections still there then in unsweat the discharge. unsweat the top 3 female prices of copper left then clean up your ends. You should have some play in the discharge to start fitting the valve in now. It takes some work to fit the top 3 in but it can be done. Use thermopaste and a lot of heat and braze back together and instantly cool off with a wet rag. You should be good to go.

[karsthuntr]

If you're changing out the valve I would sawzall the top 3 lines at the bad reversing valve body so that you have the female side of the reversing valve connections still there then in unsweat the discharge. unsweat the top 3 female prices of copper left then clean up your ends. You should have some play in the discharge to start fitting the valve in now. It takes some work to fit the top 3 in but it can be done. Use thermopaste and a lot of heat and braze back together and instantly cool off with a wet rag. You should be good to go.

If you cut the top three without unbrazing the bottom one your shavings will fall into the comp. discharge line.

[themetalhead]

If you cut the top three without unbrazing the bottom one your shavings will fall into the comp. discharge line.

I agree. plus it can already be a cluster in there, especially on WS HPs. I prefer to unsweat everything and have as few joints to braze as possible.

[dandyme]

brazing/un-brazing etc does not generates any phosgene gas, another old wives tale.

he didn't imply phosgene gas was generated he stated encountered, you should have been in the cramped area i was in unsweating the 4 way valve i replace saturday, plenty of hacking and coughing going on

any trapped gas is going to be unpleasant