Blow out preventers

摘要

A blow out preventer (10) includes a housing (40) defining a longitudinal throughbore (16) and a ram cavity (34) and at least one pair of opposed rams (12, 14) located in the ram cavity. Each ram includes a seal (18, 24) disposed on an upper surface (20, 26) and the rams are movable transversely across the bore. The blow out preventer further includes at least one seal seat (30) having a seal surface (36) for engaging with the ram seals. There is a seal seat associated with each at least one pair of rams, the seal seat being moveably mounted in the ram cavity. In one embodiment the seal seat continuously engages the rams as the rams move from a cavity open position to a cavity closed position.

主权项

1. A blow out preventer including:
a housing defining a longitudinal throughbore and a ram cavity; at least one pair of opposed rams located in the ram cavity, each ram including a seal disposed on an upper surface, the rams being movable transversely across the bore in a first direction, and at least one seal seat having a seal surface for engaging with the ram seals, the at least one seal seat being associated with each at least one pair of rams, each seal seat being mounted in the ram cavity and being configured to move towards the ram seals in a second direction perpendicular to the first direction solely responsive to fluid pressure on the upper surface of the at least one pair of rams being greater than fluid pressure on an opposing surface of the at least one pair of rams, the at least one seal seat being mounted within a top surface of the ram cavity.