Abstract: The invention provides a valve assembly for use on a refrigerating pipe line to gain access to the refrigerant so that it can be removed or replaced without disassembly of the piping while repairs are being made. The assembly is a compact structure comprising a single integral body member having a stem within which is a movable pierce valve and having a transverse threaded nipple forming an internal fluid passageway controlled by the adjustment of said movable pierce valve. The valve is in non-removably position within said body and is sealed to said body by an O-ring placed in an undercut on the stem of said valve. Interchangeable clamp plates secure the pipe line to the body adjacent the point of the pierce valve. Each of two interchangeable plates has two sets of grooves so that four sizes of tubes can be accommodated by interchanging and adjusting the two clamp plates. The construction is simple but reliable and an improvement over all known prior art.