Compression fittings (sometimes called "lock-bush fittings") include a tapered, concave conical seat; a hollow, barrel-shaped compression ring (often named a ferrule); as well as a compression nut which can be threaded on to the human body with the fitting and tightened to help make a leakproof connection. They are generally http://knoxftclt.acidblog.net/17570830/fascination-about-valves-and-fittings