Pressure equalized flow control valve

A valve for controlling passage of fluid through a flow line, comprising:

• a valve body having upstream and downstream flow passages, a generally cylindrical valve chamber communicating with the flow passages, a ball for controlling fluid flow through the passages, means for operating the ball between open and closed positions and means for equalizing differential pressure in the valve chamber,
• the ball including a central passageway for communicating fluid between the passages and rotatably supported between a pair of spaced annular seat carriers in the valve chamber,
• each seat carrier being disposed in an encircling relationship around a valve seat and including an annular recess on an inwardly facing surface and an annular recess on an axially facing surface,
• the recess on the axially facing surface including an annular groove, the valve seat positioned within the recess on the inwardly facing surface and an O-ring seal positioned within the recess on the axially facing surface,
• the pressure equalization means including a fluid passage extending radially within the upstream seat carrier,
• whereby the pressure equalization passage is for communicating upstream pressure from an inlet in the annular groove in the recess on the axially facing surface to an outlet on an outwardly facing surface of the upstream seat carrier.

A valve for controlling passage of fluid through a flow line, comprising:

• a valve body having upstream and downstream flow passages, a generally cylindrical valve chamber communicating with the flow passages, a ball for controlling fluid flow through the passages, means for operating the ball between open and closed positions and means for equalizing differential pressure in the valve chamber,
• the ball including a central passageway for communicating fluid between the passages and rotatably supported between a pair of spaced annular seat carriers in the valve chamber,
• each seat carrier being disposed in an encircling relationship around a valve seat and including an annular recess on an inwardly facing surface and an annular recess on an axially facing surface,
• the recess on the axially facing surface including an annular groove, the valve seat positioned within the recess on the inwardly facing surface and an O-ring seal positioned within the recess on the axially facing surface,
• the pressure equalization means including a plurality of fluid passages extending radially within the upstream seat carriers;
• each pressure equalization passage extending from an inlet in the annular groove in the recess on the axially facing surface to an outlet on an outwardly facing surface of the seat carrier,
• whereby the pressure equalization passages of the upstream seat carrier are for communicating upstream pressure from the inlets in the recess on the axially facing surface to the outlets on the outwardly facing surface of the upstream seat carrier.