Abstract: A check valve including an outer body having a cylindrical inner bore and a shuttle within the inner bore which is arranged with an upstream, middle and downstream portion that each engage with a sliding fit the inner bore of the outer body being such that, when in a closed position, the middle portion engages with a flexible seal a sealing engagement the inner bore and when in an open position it is arranged that the liquid will flow through a passage around the middle portion which passage includes at the least a path through the outer body.

Abstract: A check valve including an outer body having a cylindrical inner bore and a shuttle within the inner bore which is arranged with an upstream, middle and downstream portion that each engage with a sliding fit the inner bore of the outer body being such that, when in a closed position, the middle portion engages with a flexible seal a sealing engagement the inner bore and when in an open position it is arranged that the liquid will flow through a passage around the middle portion which passage includes at the least a path through the outer body.

Abstract: A piston valve wherein a hollow piston type sleeve has a closed lower end surmounted by a sleeve which has a cylindrical outer surface which slides, and seals against a blank inner cylindrical surface portion of an outer body. Ports in the sleeve are moved into an open position of the valve as they traverse from the bank inner cylindrical surface portion towards the port of the outer body.