Abstract: A top seal, ram assembly, blowout preventer, and housing for a blowout preventer are disclosed according to the invention in which outer anti-extrusion plates are provided at the ends of the top seal which are adapted for bearing against a surface of the blowout preventer housing. The housing of the blowout preventer is provided with a horizontal bore having a generally rectangular cross-section with thickened vertical wall sections in the proximity of the vertical bore through the housing. The thickened wall sections are adapted to cooperate with the outer anti-extrusion plates of the top seal in order to support the pressure created in the packer and the top seal when the rams are closed.

Abstract: Bonnet securing and retracting apparatus for a ram blowout preventer is disclosed. The ram blowout preventer bonnet is retained by two bonnet studs and nuts and by bonnet bolts. Bearings in the bonnet are provided to slide on bonnet studs. To retract the bonnet from the ram blowout preventer housing, the bonnet nuts and bolts are removed, and the bonnet may be slid on the bonnet studs outwardly from the housing. Removable stop pins in the bonnet studs prevent the bonnet from sliding off the studs. After the pins are removed, the bonnet may be completely removed from the housing.This abstract of the disclosure is neither intended to define the scope of the invention, which is measured by the claims, nor is it intended to limit the invention in any way.