Abstract: An injector spool supports a plurality of ball injector assemblies having respective ball cartridges adapted to load one frac ball at a time into a ball chamber of a ball launcher of the respective ball injector assemblies to provide a horizontal frac ball injector adapted to be connected to a frac head by frac iron.

Abstract: A controlled aperture ball drop includes a ball cartridge that is mounted to a frac head or a high pressure fluid conduit. The ball cartridge houses a ball rail having a bottom end that forms an aperture with an inner periphery of the ball cartridge through which frac balls of a frac ball stack supported by the ball rail are sequentially dropped from the frac ball stack as a size of the aperture is increased by an aperture controller operatively connected to the ball rail.

Abstract: A controlled aperture ball drop includes a ball cartridge that is mounted to a frac head or a high pressure fluid conduit. The ball cartridge houses a ball rail having a bottom end that forms an aperture with an inner periphery of the ball cartridge through which frac balls of a frac ball stack supported by the ball rail are sequentially dropped from the frac ball stack as a size of the aperture is increased by an aperture controller operatively connected to the ball rail. A control console displays a user interface that permits an operator to control the controlled aperture ball drop to drop frac balls only when desired.

Abstract: An erosion resistant frac head with a convergence chamber, an expansion chamber and a mixing chamber provides improved resistance to erosion caused by abrasive frac fluids pumped through the frac head. A bottom leg of the erosion resistant frac head terminates in a flange and may be replaced in the field by field hands.

Abstract: A frac head is provided with a sacrificial wash ring. The sacrificial wash ring is located above a mixing chamber of the frac head. The sacrificial wash ring protects the frac head body from erosion caused by abrasive frac fluids pumped through the frac head.

Abstract: A controlled aperture ball drop includes a ball cartridge that is mounted to a frac head or a high pressure fluid conduit. The ball cartridge houses a ball rail having a bottom end that forms an aperture with an inner periphery of the ball cartridge through which frac balls of a frac ball stack supported by the ball rail are sequentially dropped from the frac ball stack as a size of the aperture is increased by an aperture controller operatively connected to the ball rail.

Abstract: A controlled aperture ball drop includes a ball cartridge that is mounted to a frac head or a high pressure fluid conduit. The ball cartridge houses a ball rail having a bottom end that forms an aperture with an inner periphery of the ball cartridge through which frac balls of a frac ball stack supported by the ball rail are sequentially dropped from the frac ball stack as a size of the aperture is increased by an aperture controller operatively connected to the ball rail.

Abstract: A threaded union for tubulars used for high-pressure fluid applications includes a unitary nut supported by at least two nut retainer segments received under a top wall of the nut in an annular segment retainer groove in one of the tubulars. The nut retainer segments fully support the unitary nut. The nut retainer segments are held in the annular segment retainer groove by securing the nut retainer segments in the segment retainer groove.

Abstract: A threaded union for tubulars used for high-pressure fluid applications includes a unitary nut supported by at least two nut retainer segments received under a top wall of the nut in an annular segment retainer groove in one of the tubulars. The nut retainer segments fully support the unitary nut. The nut retainer segments are held in the annular segment retainer groove by securing the nut retainer segments in the segment retainer groove.

Abstract: A quick-change wear sleeve for a high pressure fluid conduit is retained in a fluid passage of the fluid conduit by a resilient retainer ring received in complementary grooves in an outer surface of the quick-change wear sleeve and an inner surface of the fluid passage.

Abstract: A threaded union for tubulars used for high-pressure fluid applications includes a unitary nut supported by at least two nut retainer segments received under a top wall of the nut in an annular segment retainer groove in one of the tubulars. The nut retainer segments fully support the unitary nut. The nut retainer segments are held in the annular segment retainer groove by securing the nut retainer segments in the segment retainer groove.