Swivel joint for oilfield pumping stimulation

Abstract

A swivel joint includes a tubular female member which is rotatably connected to a tubular male member. The female member includes a female race portion having an axially extending inner annular recess, a female inner end portion which is formed at an axially inner end of the recess, and a number of inner annular grooves which are formed in the recess coaxially therewith. The male member includes a male race portion having an annular outer surface which is configured to be received in the recess, a male nose portion which is formed at an end of the male race portion, and a number of outer annular grooves which are formed on the outer surface coaxially therewith. The male race portion is positioned in the female race portion such that the male nose portion is located adjacent the female inner end portion and each outer groove is aligned with a corresponding inner groove to thereby define a number of annular bearing races within which a plurality of balls are received to thereby rotatably connect the male member to the female member. A first primary seal is positioned between the male nose portion and the female inner end portion, and a second seal is positioned between the male nose portion and the female inner end portion radially outwardly of the first primary seal. The male nose portion comprises an end wall which extends radially outwardly from the flow bore and a conical side wall which extends both radially and axially outwardly relative to the cylindrical side wall, and the second seal comprises at least a first portion which sealingly engages the conical side wall.