NIBCO’s Press ACR is approved for use with a wide range of refrigerants and lubricants. The fittings are UL recgonzied to 700 PSI, and feature a gray HNBP seal to help differentiate them from other NIBCO press products. Straight and reducing couplings, 45- and 90-degree elbows, caps, Y-joints and tees are available in sizes 1/4", 1/2", 3/8", 5/16", 5/8", 7/8" and 1 1/8". NIBCO.