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NPT fittings in an AC system?

NPT fittings in an AC system?

NPT fittings in an AC system?

(OP)
If you folks were to review a design for a vehicle AC system that included a manifold with NPT connections, what would you say? Seems to me that NPT is a bad choice for moving R-134a, won't it bleed out over time.(even with pipe dope)

Correct me if I'm in error.

thanks

RE: NPT fittings in an AC system?

A/C fittings should be SAE, type and preferrably backed up with an O-ring system.  Vibration is severe in this application.

RE: NPT fittings in an AC system?

NPT is the work of the devil.

RE: NPT fittings in an AC system?

Who in the world would use an NPT connection on a R-134a unit?

Since they are already there, you need to clean them well and coat them with A Loctite product specifically for refrigerant service.  It will hold pretty well and can be heated to remove the plug later.

Ken

Ken
KE5DFR

RE: NPT fittings in an AC system?

(OP)
Thanks for your help.

The short answer is someone that has no buisness designing things specified a manifold with NPT connections.

RE: NPT fittings in an AC system?

NPT threads have been used on refrigeration systems for years For example, all the gauges as in manifold gauges used on refrigeration systems are NPT. In amonia systems a lot of the piping systems are NPT.

RE: NPT fittings in an AC system?

(OP)
imok2

Thanks for your input. Are the manifolds you are referring to "in-line" (ie) constantly presurrized or are you talking gage manifolds for checking the high and low side as a diagnostic tool?

RE: NPT fittings in an AC system?

Both!

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