Rotary valve with seat assembly

A method of assembling a rotary valve for controlling a line pressure, comprising:

• providing a valve body with a valve chamber therein;
• providing first and second passages that extend through said valve body and which are in communication with said valve chamber to define a flow path through said valve body;
• providing a first recess surrounding said first passage adjacent to said valve chamber and a second recess surrounding said second passage adjacent to said gate chamber;
• providing a rotary valve element for said valve chamber that is rotatably moveable between an open position and a closed position;
• providing a valve stem for rotating said rotary valve element;
• providing a first telescoping seat assembly with first and second seat elements for said first recess and a second telescoping assembly with first and second seat elements for said second recess;
• providing a line pressure surface in said first telescoping seat assembly to thereby expand said first and second seat elements of said first telescoping seat assembly outwardly with respect to each other to form a seal with said rotary valve element and with said valve body;
• and
• providing a connection between said valve stem and said rotary valve element that permits lateral movement of said rotary valve element with respect to said valve stem to thereby permit said rotary valve element to compress said first and second seat elements of said second telescoping seat assembly due to pressure on said rotary valve element when said rotary valve element is in said closed position to thereby seal with said rotary valve element and said valve body.

A seating assembly for a rotary valve for controlling line pressure, said rotary valve having a valve body with a passageway therethrough and a valve chamber with a rotary valve element, said rotary valve element being rotatable between an open and a closed position and having a first curved seal surface, said valve body defining recesses on either side of said valve chamber surrounding said passageway, said seating assembly comprising:

• a first telescoping seating assembly and a second telescoping assembly mountable on opposite sides of said rotary valve element and being disposed in respective of said recesses on either side of said valve chamber;
• said first telescoping seating assembly comprising first and second seating elements which are moveable with respect to each other, said first seating element having a second curved seal surface for engaging said first curved seal surface of said rotary valve element, said first telescoping seating assembly having a line pressure surface on which said line pressure is receivable to produce a contact stress between said first seating element and said rotary valve element, said contact stress being variable over said first and second curved seal surfaces, said line pressure surface being sized to produce a contact stress greater than said line pressure over a sufficient portion of said first and second curved seal surfaces to produce a gas tight seal, said second seating element being moveable by said line pressure away from said first seating element to thereby seal along a respective of said recesses.

A rotary valve having a valve body for containing a line pressure with a passageway extending through said valve body, said rotary valve comprising:

• a rotary valve element for controlling flow through said passageway;
• a stem driver for rotating said rotary valve element between an open and closed position;
• first and second pairs of telescoping seating elements mounted within said valve body for sealing with said rotary valve element;
• a connection formed between said rotary valve element and said stem driver to permit lateral relative movement between said stem driver and said rotary valve element in at least one direction when said rotary valve element is in said closed position.

A plug valve, comprising:

• a valve body having a passageway therethrough and defining therein a valve chamber;
• a bonnet secured within said valve body and being removable through a service opening in said valve body;
• a cylindrical plug mounted in said valve chamber and rotatable between and open and closed position;
• a valve stem mounted within said bonnet for rotating said cylindrical plug, said cylindrical plug being moveable laterally with respect to said valve stem;
• first and second telescoping pairs of seating elements mounted on either side of said cylindrical plug.

A seating assembly for a rotary valve for controlling line pressure, said rotary valve having a valve body with a passageway therethrough and a valve chamber with a rotary valve element, said rotary valve element being rotatable between an open and a closed position and having a first curved seal surface, said valve body defining first and second recesses on either side of said valve chamber surrounding said passageway, said seating assembly comprising:

• a first telescoping seat assembly for said first recess;
• a second telescoping seat assembly for said second recess;
• a first unidirectional seal element positioned within said first telescoping seat assembly;
• and
• a second unidirectional seal element positioned within said second telescoping seat assembly.