Patent ID: 8800954
Filing Date: 2014-08-12
Classification: E21B

Abstract:
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.