초록 ▼

A plug valve having a valve body with a cylindrical plug receiving opening extending therethrough having at least one terminal end thereof outwardly chamfered. Fluid inlet and outlet passageways communicate with the receiving opening and are chamfered at the areas of communication therewith. A plug

A plug valve having a valve body with a cylindrical plug receiving opening extending therethrough having at least one terminal end thereof outwardly chamfered. Fluid inlet and outlet passageways communicate with the receiving opening and are chamfered at the areas of communication therewith. A plug member includes a cylindrical plug portion closely received in the body receiving opening. This plug portion has a transverse fluid flow passage which is selectively rotatable into and out of alignment with the valve body inlet and outlet passageways. Axially spaced apart circumferential sealing members disposed on both sides of the flow passage prevent fluid flow outwardly of the receiving opening. An inlet passageway sealing means disposed in the plug portion side wall intermediate the opposite flow passage ends sealingly surrounds the passageway in the valve closed position. A fluid relief channel communicating between the flow passage and plug portion side wall relieves fluid pressure through the outlet passageway as the valve is moved to the closed position. The plug portion advantageously includes a thin coating of plastic material for enhancing its fluid sealing relationship with the receiving opening and for improving ease of rotation between the valve opened and closed positions. The plug member is axially retained in position in the receiving opening by a snap ring at one end and by a handle at the other end. The handle is rotatable only between positively defined maximum valve opened and closed positions. Spaced apart circumferential grooves included in the plug portion side wall receive the axially spaced apart sealing members and at least the bottom walls of these grooves are also coated with the plastic material.

대표청구항 ▼

A plug member for a plug valve comprising: an elongated generally cylindrical plug portion having an outer surface and opposite stem and locking ends, circumferential seal receiving grooves adjacent said stem and locking ends, seals received in said seal receiving grooves, a circumferential snap rin

A plug member for a plug valve comprising: an elongated generally cylindrical plug portion having an outer surface and opposite stem and locking ends, circumferential seal receiving grooves adjacent said stem and locking ends, seals received in said seal receiving grooves, a circumferential snap ring receiving groove in said outer surface between said locking end and said seal receiving groove which is adjacent said locking end, a lateral flow passage through said plug portion intermediate said seal receiving grooves and having inlet and outlet ends, a continuous groove in said outer surface intermediate said seal receiving grooves and intermediate said inlet and outlet ends, said continuous groove having generally parallel inner and outer side walls and a bottom wall, said inner side wall having a depth greater than the depth of said outer groove side wall such that said groove bottom wall tapers inwardly away from said plug portion outer surface in a direction from said outer groove side wall toward said inner groove side wall and does not extend perpendicular to either of said groove side walls, a continuous seal received in said continuous groove and encompassing a closed seal area for sealingly surrounding an inlet passageway in a plug valve body, a pressure relief groove in said outer surface extending from said outlet end of said flow passage over a short circumferential arc on the opposite side of said outlet end from said continuous groove, said outer surface being smooth and ungrooved adjacent said inlet and outlet ends of said flow passage except for said pressure relief groove, an integral stem extending outwardly from said stem end, a handle secured to said stem and having a generally flat face extending generally radially outwardly beyond said outer surface of said plug portion, a recess in said flat face for receiving a projection on a valve body, said recess having opposite stop surfaces spaced over an arc for cooperation with a projection on a valve body to limit rotation of said plug member over an angle generally the same as the angle between the center of said closed seal area and the center of said inlet end of said flow passage, and said recess and stop surfaces having a predetermined relationship to said inlet and outlet ends and said continuous seal for insuring proper installation of said plug portion in a plug body.