Side feed water swivel

Abstract

A side feed water swivel for a hollow drill string includes a spindle one end of which is adapted to fit a socket on a rotary table of a drill rig, and the other end, to connect to hollow drill rods, and, intermediate its ends, a receiving section having upper and lower smooth cylindrical bearing surfaces and between them water-receiving passages extending to an axial passage blind at its upper end, and a housing embracing the bearing surfaces and defining between them a water-receiving chamber. The housing has an inlet port extending through a wall to communicate with the chamber substantially midway axially of the housing. The housing has upper and lower bearing surfaces complementary to the spindle bearing surfaces. O-ring channels in the housing bearing surfaces are positioned axially asymmetrically with respect to the center line of the housing. The housing is so made that it can be mounted on the spindle in either of two orientations 180.degree. apart so that when one pair of sealing surfaces is worn, the housing can be removed from the spindle, inverted and remounted to permit the O-rings in the channels to engage a new set of sealing surfaces.