Textbook question - piercing valves

[Pion]

When necessary, I usually will only use piercing valves to recover refrigerant and install permanent access fittings.

[karsthuntr]

When necessary, I usually will only use piercing valves to recover refrigerant and install permanent access fittings.

That's why you use the top picture I posted. You braze it in (with it full of gas) and leave it there. Its a single step instead of using the bolt on one and then removing it and brazing in something else.

[nashuahvac]

You are supposed to use the piercing fitting to pull out the refrigerant. Then you braze on a new process tube and use one of these http://www.sjdiscounttools.com/rob12458.html to attach your hose to the end of the process tube (its like a rubber compression fitting) and charge by weight. Then you pinch off the tube, remove the fitting and braze over the end of the process tube. This way everything is still hermetic when you are done. It's not that hard as long as you make sure the process tube is long enough to work with.

Really though, just braze on a regular access fitting and be done with it.

[hceptj]

That's why you use the top picture I posted. You braze it in (with it full of gas) and leave it there. Its a single step instead of using the bolt on one and then removing it and brazing in something else.

Same here...had a 20+ year old 10 ton Lennox with a defective high pressure switch a couple weeks ago, no core under the bad switch so I just brazed in the new service valve and wired in a new high pressure switch...took longer to go to the parts house than it did to do the work...

[karsthuntr]

Same here...had a 20+ year old 10 ton Lennox with a defective high pressure switch a couple weeks ago, no core under the bad switch so I just brazed in the new service valve and wired in a new high pressure switch...took longer to go to the parts house than it did to do the work...

Lennox is where I found out about the brazed saddle valves. I had a pressure switch go bad on a lennox unit. Lennox sent me the saddle valve and a screw on pressure switch and said to leave the old one in since it was brazed in.