GB665511A - Improvements in control valves - Google Patents

Abstract

665,511. Piston valves. AKTIEBOLAGET KARLSTADS MEKANISKA WERKSTAD. July 7, 1949 [July 10, 1948], No.' 18000/49. Class. 135. A piston valve in which the piston is balanced axially by the pressure of the fluid passing through the valve comprises a cylinder having fluid inlet and outlet ports 55, 57 respectively, a rotatable liner 13 having sets of ports 45, 47, 49, 51 communicating respectively with grooves 37, 39; 41, 43 in the housing, and a piston formed with lands 25, 27 having flutes or grooves 35, 36. As shown, the fluid flows from the inlet 55 through the wedge-shaped spaces between the liner wall and the flutes 35 and the ports 47 into a duct 53 and thence through the ports 51 and the spaces between the liner wall and the flutes 36 to the outlet 57. 'The valve may be used in a governor for water turbines, the piston being actuated mechanically by a centrifugal governor or electrically by a solenoid the current to which is derived from an electric power system fed by a generator driven by the turbine. The Specification as open to inspection under Sect. 91 comprises also a valve having a piston formed with a land having grooves 77, Fig. 3 (Cancelled). In this case, the fluid enters ports 81, 83 and leaves by ports 95 disposed at 90 degrees to the intake ports. This subject-matter does not appear in the Specification as accepted.