Abstract: A valve of simplified construction, adapted to control fluid of high volume and pressure. The valve plunger is a hollow metal tube, that controls fluid flow by moving radial slots in its peripheral wall back and forth across a seal. The plunger is moved by an air or hydraulic cylinder which is connected to the plunger by a plate ring. The plate ring has a series of holes therethrough that allow the line media to flow through, out of and around the plunger to create a balancing effect and thus decrease opposition to movement of the plunger, which opposition may be caused by forces created by the line media. The improved valve utilizes double-acting seals to isolate a down stream port, and to seal off the increase in pressure downstream when the valve is closed.

Abstract: A valve construction, particularly a three-way, two-position valve which may be used by itself to control fluid flow, or which may be used as a pilot valve to control operation of a larger valve. The valve comprises a cartridge which may be installed within or removed from the bore of a valve body as a unit. The cartridge unit comprises a valve plunger, a plurality of similar glands, and a plurality of similar separators carried by the plunger, with static seals on the glands and dynamic seals between separators, and a spring for urging the plunger to a predetermined position.The cartridge unit is held within a body bore by means of a cartridge nut which is threaded into one end of the bore. The nut has one end bearing against a separator at one end of the cartridge unit and presses a separator at the other end of the unit against a fixed abutment in the bore, so that axial movement of the plunger does not cause separation of the glands and separators.