The P-Trap features solder cups. A major application of the fitting is on the suction line of a refrigeration compressor. The line is looped, by use of the P-Trap, to the floor prior to being run vertically upwards to prevent the drainage of oil back to the compressor during shut-down periods. Additional P-Traps are used for each 20 feet of riser pipe; this prevents high velocity build-up as the oil or liquid begins to return to the compressor during the shut-down period. Please refer to NIBCO technical data sheets and catalogs for engineering and installation information. In addition to its inh