Abstract: A liquid flow control device has a port or passageway through which liquid flow is to be controlled. A body of a liquid swellable material is located in the port or passageway having an upstream side and a downstream side in relation to the direction of liquid flow through the port or passageway. A layer of sealing material is provided on the upstream side of the body to prevent contact of that side of the body with the liquid when the body is swollen to close the port or passageway whilst allowing contact of the downstream side of the body when the body is in the non-swollen condition allowing liquid flow through the port or passageway.

Abstract: A liquid flow control device includes an annular housing having an inlet for liquid in one periphery of the housing and an outlet for liquid in the other periphery. An annular block of water swellable material is located in the housing. A layer of sealing material encircles the annular block on the side thereof adjacent the inlet to close the inlet when the block is swollen through contact with the liquid.

Abstract: A collet for locking a tube in a tube coupling body is moulded in plastics and comprises an annular collar having a plurality of arms extending from the collar generally parallel to the collar axis. Each arm has a head at its distal end spaced from the collar for engaging between a tube and coupling body to lock the tube in the coupling body. Different materials are used for the heads of the collet and the rest of the collet whereby the heads are stronger and relatively rigid whereas the rest of the collet is relatively flexible.