Ball valve with seat loading mechanism

Abstract

A top-entry ball valve 10 comprising a valve body 12 having a chamber 13, flow passages 14, 15, a ball 20 rotatably mounted in the chamber for movement between open and closed positions relative to the passages, and a pair of seat assemblies 50 at opposed sides of the ball which may be loaded into engagement with the ball or disengaged therefrom. Each seat assembly 50 comprises a seat ring 51 having a rear portion 51a, a larger diameter portion 51b which forms a shoulder 51c, and a face seal 59. Three pins 65 in the seat ring 51 in equiangular spaced relation project from the shoulder 51c. A spacer ring 53 sleeved about the rear 51a of the seat ring 51 is provided with recesses 68 adapted to receive the pins 65. The spacer 53 is mounted for movement between a first position where it is engaged by the tips of pins 65 and a second position wherein the pins 65 are in the recesses 68. A spring assembly 66 between the spacer 53 and a shoulder 42 of seat pocket 35 continuously urges the spacer to its first or second positions. The bar may be used to pry the spacer from shoulder 51c and the seat assembly towards the ball 20. A pin 71 on the spacer 53, when the valve cover 28 is removed, may be engaged by a pry bar to move and rotate the spacer to its first or second positions. The bar may be used to pry the spacer from shoulder 51c and re-orient the spacer so the seat ring is loaded against the ball 20. Placing the spacer 53 in its second position, retracts the seat from ball 20 and adapts the valve for in-line removal of ball and seats.