Shaffer Type Annular Bop / Blowout Preventer For Wellhead Pressure Control Equipment

In case of blowout and well-sealing is needed, high pressure oil coming from control system enters the bottom closing chamber from bottom inlet to push piston moving upward. The movement of piston forces rubber core to move upward along the sphere surface, then supporting ribs get closer to push the internal rubber moving towards the wellhead center to fulfill the function of sealing drill equipment or the wellhead. When unlocking the seal is needed, hydraulic oil pushes the piston moving downward and the rubber core will reset to its original position under its elastic force.

Structure Characteristics:

1. The connection between top cap and housing, top and bottom ends adopt flanges and bolts.

2. Smisphere rubber core has many advantages, such as not easy folding back, big volume of rubber storage. Under the well pressure,the piston pushes the rubber core upward to form a funnel shape. The funnel effect of rubber core increases its sealing performance and life span.

3. Characteristics of the sealing structure

1)The BOP has three important sealing positions: piston external surface seal, piston internal surface seal and mud blocking ring seal.

2)Radial direction cross section of the piston comes of the shape "Z", which makes the piston have short stroke length, low height and big diameter.