Also called "Chicago," "CP," or "Crow's Foot" couplings. Used to connect air lines from compressors or other air sources to all types of pneumatic tools and equipment. All 2-lug head connections are of one size for easy interchange. Hose shank or threaded end is coupling size. Male and female threads are NPT. Malleable iron plated. (European style universals are available by special order.) Universal crowfoot couplings are recommended to be used in the transfer of air and/or water.  The application should be in an open system where the air or water is in motion (dynamic) and not in a closed, pressurized (static) condition. This dynamic application involves continuous flow; therefore, back pressure would be relieved by the very nature of the application. The applicable system should contain pressure relief valves to relieve any excess pressure. Safety clips and safety cables should be installed on either side of the coupling connection. The rated, maximum working pressure of Universal Crowfoot Air Hose Couplings is 150 psi (at ambient temperature - 70ÅãF) for all parts. Standard parts are iron; parts are available made of other metals.