Metallic seat construction for valves

A metallic seat assembly for a valve having a valve body with inlet and outlet passageways communicating with a valve chamber and a valve member mounted in said valve chamber movable between open and closed positions, said seat assembly comprising:

• an annular seat pocket around one of said passageways and opening to said valve chamber;
• an outer annular seat support member mounted in said seat pocket;
• an inner annular seat member received within said outer seat support member and adapted for longitudinal movement in the seat support member toward and away from the valve member;
• and
• an annular flexible member between the outer seat support member and the inner seat member, said flexible member being secured adjacent one peripheral portion to said seat support member and secured adjacent the other peripheral portion to said seat member, said seat member having an annular planar sealing face and an annular face seal engageable with said valve member extending from said sealing face, said face seal having a lip seal element integral with the seat member with the free end of said lip seal element extending beyond said sealing face, said lip seal element being substantially wider in cross-section at a root portion thereof than at said free end and having a generally frusto-conical shape with said free end being at the smaller diameter portion thereof, said seat member having an annular groove in said planar sealing face with said lip seal element extending from the bottom of said groove and said groove being of sufficient width so that said lip seal element can be deflected to be completely enclosed inside said groove without contacting either side of said groove.

A metallic seat assembly for a gate valve having a valve body with inlet and outlet passageways communicating with a valve chamber and a gate valve member mounted in said valve chamber movable between open and closed positions, said seat assembly comprising:

• an annular seat pocket around one of said passageways and opening to said valve chamber;
• a metallic annular seat member mounted in said seat pocket and having a front face sealingly engageable with said valve member;
• a metallic lip integral with said metallic seat member extending from said front face with the unattached free end of said lip extending beyond said seat front face when said lip is in a free position;
• and
• an annular groove in said seat member adjacent said metal lip, said lip normally resting in sealing contact with said valve member and said lip being deflectable into said groove such that said seat front face can engage said gate valve member in flush surface contact.

In an expanding gate valve structure having a valve body with inlet and outlet passageways communicating with a valve chamber therein and an annular recess about each passageway, and a gate assembly mounted in said valve chamber for movement between open and closed positions and including a gate and a segment carried thereby expanding away from each other at the open and closed positions;

• an improved metallic seat assembly within each annular recess, said seat assembly comprising:
• an outer generally L-shaped annular seat support member press fitted in a fixed position within the associated recess and defining inner and outer legs in generally flush contact with the walls defining the recess;
• an inner metallic seat member mounted within the seat support member for floating movement relative to the outer seat support;
• and
• an annular flexible spring member between the outer seat support member and the inner seat member and having a relatively thin cross-section, said flexible spring being secured adjacent its inner periphery to the inner leg of said seat support member and secured adjacent its outer periphery to said seat member, said inner seat member engaging the outer seat support member in abutting relation upon expanding of said gate valve assembly at the fully closed position of the gate assembly.

In a gate valve having a valve body with inlet and outlet passageways communicating with a valve chamber therein and an annular recess about each passageway, and a gate mounted in said valve chamber for movement between open and closed positions;

• an improved metallic seat assembly within each annular recess, said seat assembly comprising:
• an outer generally L-shaped annular seat support member press fitted in a fixed position within the associated recess and defining inner and outer legs in generally flush contact with the walls defining the recess;
• an inner metallic seat member mounted within the seat support member for floating movement relative to the outer seat support;
• and
• an annular flexible spring member between the outer seat support member and the inner seat member and having a relatively thin cross-section, said flexible spring being secured adjacent its inner periphery to the inner leg of said seat support member and secured adjacent its outer periphery to said seat member, said inner seat member adapted to engage the outer seat support member in abutting relation upon movement toward said seat support member.

In an expanding gate valve structure having a valve body with inlet and outlet passageways communicating with a valve chamber therein and an annular recess about each passageway, and a gate assembly mounted in said valve chamber for movement between open and closed positions and including a gate and a segment carried thereby expanding away from each other at the open and closed positions;

• an improved metallic seat assembly within each annular recess, said seat assembly comprising:
• a metallic annular seat member mounted in each recess and having a front face sealingly engageable with said gate assembly;
• a metallic lip integral with said metallic seat member extending from said front face with the unattached free end of said lip extending beyond said seat front face when said lip is in a free position;
• and
• an annular groove in said seat member adjacent said metal lip, said lip normally resting in sealing contact with said gate assembly and said lip being deflectable into said groove such that said seat front face can engage said gate assembly in flush surface contact, said metal lip being substantially wider in cross section at a root portion thereof than at said free end.