View Full Version : P-Trap standards(?) for Refrigerant Piping

10-07-2014, 08:10 AM
Hi All,

Just a quick one... is there (or was there ever) a kind of Rule-of-thumb in making a P-trap in a refrigerant pipeline?

I tried cross-referencing/checking on plumbing books and procedures but it didnt gave me an assured answer other than that it'll work as long as there is a proper "seal". However we are talking about ref piping here so there might be a more better explanation to have.

Thanks in advance.

The Viking
10-07-2014, 12:24 PM

I always worked on "at least the diameter of the bender"...

However, somewhere in the back of my mind I seem to have "minimum of 3 pipe diameters"


10-07-2014, 09:06 PM
"P" trap to be as small as possible so as not to collect any more oil than necessary.
to my understanding it is not like a water "P" trap, but a trap where the oil droplets will collect & return in the gas flow down the suction line.
The oil is miscible with the refrigerant so mixes with the flow over it.
If your traps are to big they can collect to much oil out in the system.