Rotary valve head operated by 90 degree rotation - has two relatively rotatable sealing discs with movement limited by stop lugs engaging axial tongues on housing sleeve

摘要

The valve head has a sealing ring applied against the inlet, a fixed lower sealing disc being held against the joint. The disc has a flow orifice and a polished upper surface slidably engaged by the lower surface of an upper disc rotatably coupled to an external operating member by interengaging reliefs. A cylindrical sleeve has longitudinal tongues (17a, b) these defining two lateral flow openings. The lower disc is fixed in the sleeve and has flow apertures, rotation of the upper disc being limited by stops surfaces on lugs (21) Cavities define outflow openings. The head varies the flow from zero to max. by rotation through 90 deg., its construction being less complex than prior art.