Tell me about it. I’ve got three warranty jobs lingering due to part shortage. If/when the parts become available it’ll be a long job full of labor. A True rep told me he’d recently authorized a warranty repair exceeding the cost of the equipment by three times. 3X THE COST!! I’ve got this cap tube, another cap tube leak on a 290 unit, and an evap on another 290 unit. Whatever, it’s all green to me.


Well, as much as I hate to say…. I didn’t worry about it.


Can’t nitro purge every joint you ever do, do your best and forget the rest. How do you nitrogen purge a check valve? It’s impossible from either side.


Can’t even find nitro. Ive been having to pressure test with refrigerant


Can confirm.


Good point.


More of a on/off purge than a steady flow. I Run the nitro low and then separate the joint slightly so the nitro flows toward the joint. Put it together Shut off nitro Hit it quick.


Add suction and liquid service ports, flow from farther one to one closer to weld


Depends on the joint, if flowing through ports is not possible, i'll a) tape a schrader really good then flow or b) purge through line till the joint, stop put joint back in and braze fast or c) I brazed a cap tube to a schrader valve that I push inside the line till I reach the braze area and then flow. It'll keep flowing/purging from the braze area back out from where I put it. I've had to replace RTU cap tubes so I just make a new distributor/cap tube metering device. But I can't flow through it because captubes/filler material will push out. So I just put it on a metal surface, tape a schrader before the distributor and braze the cap tubes while flowing backwards. Then for brazing a liquid line pipe I just insert it, push the nitro captube in and flow backwards. Then In the field I can just braze it while flowing normally.


All great techniques for multiple applications/scenarios.


I don't because my system isn't big enough to care. Triple evac works just fine.


Agreed. Just how much carbon deposits are left behind on a 1/4” coupling.


But I know it’s there. And cap tubes care.


If it's 134a then cap tubes do care, but I'd be doing my customer a disservice if I didn't charge all 134a cap tube systems with hotshot, after changing drier, of course.


What is hotshot? Never heard of that before.




What advantage does that have for the system?


Runs similar pressures. Same compressor oil. Cheaper than 134a. Less likely to restrict. Hotshot used to be 414b which replaced r12. 134a on its way out. Why charge with an obsolete gas that regularly restricts?


Interesting. I don’t work on a lot of 134a, no one I know uses hotshot up here but I’m intrigued. The fact that it’s less likely to restrict is a selling feature in itself.