Blowout preventer, shear ram, shear blade and seal therefor
This patent describes a blowout preventer having a pipe passage with guideways extending laterally from opposite sides of the pipe passage, and rams mounted in the guideways with opposed shear blades extending from the rams for movement between a spaced apart position to receive pipe in the pipe passage to an engaged position for shearing the pipe without crushing it and for sealing off the pipe passage. Each ram has a face with a central cutout portion for receiving the uncrushed sheared pipe. The improvement described here comprises: the opposed shear blades having generally flat upper and lower parallel surfaces with front, back and longitudinal side surfaces extending between the upper and lower parallel surfaces, the front surface forming a shear surface on the opposed shear blades; the shear surface on each of the opposed shear blades including guide surfaces extending toward the back surface and coveraging inwardly from the side surfaces. The guide surfaces terminate at their inner ends in an arcuate portion and the arcuate portion has an annular tapered cutting surface that extends on a diagonal plane between the upper and lower surfaces; and seal means on the opposed shear blades shaped to telescopically receive and sealingly engage the side and shear surfaces of the opposed blades when the rams are engaged to seal off the pipe passage when the pipe has been sheared.
- Assignee:
- NOV; NOV-87-050586; EDB-87-062313
- Patent Number(s):
- US 4646825
- OSTI ID:
- 6759464
- Resource Relation:
- Patent File Date: Filed date 2 Jan 1986
- Country of Publication:
- United States
- Language:
- English
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