Water swivels are connected to the top of the drill string and provide an effective water-tight seal between the rotating and non-rotating parts of the string, allowing water or other drilling fluids to be pumped to the bottom of the drill string.
A range of water swivels are manufactured with various capacities. Illustrated is a general purpose 5-ton water swivel with lifting bail. It has a maximum rotation speed of 2500 r.p.m. and a static carrying capacity of 5000 kg, with a side inlet port of 1″ BSP. The spindle is made from high-grade alloy steel, heat-treated or hard-surfaced to resist severe stresses. It is suspended in the water swivel body by a double bearing arrangement. At the bottom end of the spindle is a left-hand thread to which an appropriate adaptor is attached to connect to the drill rods.