Abstract: There is disclosed a pipe repair coupling including a barrel formed centrally with a hollow cylinder for telescopical receipt therein of a hollow piston. The barrel is surrounded by a protective sleeve and is formed at one extremity with a first fitting and at the opposite extremity with a neck portion. The piston is formed in its exterior with a plurality of annular O-ring grooves which receive O-rings for dynamic sealing engagement with the interior wall of the barrel. Telescoped within the hollow piston in the area of the O-rings is a tubular stiffener which supports the walls of such piston against radial inward collapse. Consequently, the piston may be telescoped into the cylinder to facilitate connection of the cylinder fitting to an end of a pipe which is aligned axially with a second end spaced therefrom. Such second end may then be easily connected with a fitting formed on the end of the free end of such piston.

Abstract: A very reliable, trouble-free, safety shut-off is provided by a poppit valve arranged so that it can be included in series in a flow line. The head of the poppit is mounted upstream from the seat. It is biased open so that fluid can flow through the line at any rate from zero up to some maximum flow velocity. Flow through the valve is arranged so that it impinges upon the valve head, or something fixed to the valve head, whereby kinetic energy is lost at the head. That kinetic energy is used to move the valve head toward the seat until the spacing between them becomes so small that flow velocity is restricted. At that time, velocity through the valve is increased to the point where a large pressure drop appears across the valve and the static head of the fluid is used to force the valve closed and to maintain it closed. A dash pot develops viscous friction which is used both to damp any tendency of the head to oscillate and to prevent valve operation in response to short term transients or perturbations.

Abstract: A threadless coupling for rapid connection to a valve or fitting and to pipes or tubing for fluid distribution systems such as for gas or water. The coupling comprises an outer housing having an internal arrangement of O-rings and unique spacers, lock rings and other members for gripping tubing when inserted and, once inserted, the tubing is firmly gripped to provide a substantial amount of tensile resistant loading thereon.