GB1490438A - Well flow control valve method and apparatus - Google Patents

Abstract

1490438 Wells &c. HYDRIL CO 27 May 1975 23126/75 Heading E1F A well flow control valve, e.g. a safety valve, includes a rotatable flow control element 36 which sealingly engages a valve seat which includes a resilient annular seal 40 and operating means which space the valve seat 40 from the control element 36 prior to rotating the control element 36. As described the flow control element 36 is a ball (Fig. 1B) which is engaged by eccentrically mounted pins 100 fixed to the valve housing and by lugs 56b of a control frame 56, downward movement of the control frame 56 thus rotating the ball 36 to its open position. The ball 36 engages an upper seat 42 formed at the lower end of an upper operating sleeve 104 and a lower seat including resilient seat 40 mounted in the upper end of a lower operating sleeve 52. A projection 52c on the sleeve 52 engages a slightly larger recess 56c in the central frame 56. The sleeves 52, 104 are urged upwardly by spring 64, 122 respectively to hold the ball 36 in its closed position. The ball 36 is moved to its open position by moving the sleeves 52, 104 downwardly. Sleeve 52 is moved downwardly by downward movement of either one of annular pistons 80 and 86. The space 96 between pistons 80, 86 is connected via ports 68d and 156b and passage 156 to a first control line L1 and the spaces above piston 80 and below piston 86 are connected to a second control line L2 (not shown). Thus an increase in pressure in one of the lines L1, L2 relative to the other will cause downward movement of one of the pistons 80, 86 and thus downward movement of the sleeve 52. The sleeve 104 is moved downwardly by pressure in the one of the lines L1, L2 by a similar arrangement including annular pistons 124, 126. In use downward movement of sleeve 52 moves the seat 40 away from the ball 36 and when the projection 52c engages the bottom of recess 56c moves the control frame 56 downwardly. This moves the ball 36 downwardly away from seat 42 and rotates it to its open position. Downward movement of sleeve 104 is delayed by well pressure acting on piston surface 104d of sleeve 104 until the ball 36 moves to its open position and permits well pressure to act via port 104b on surface 104a. The sleeve 104 then moves downwardly to engage the ball 36, moving it to its fully open position and seating it against seat 40. The above sequence is reversed when the valve is closed by the action of springs 64, 122 when pressure in line L1 or L2 is removed.