This tank cleaning head is a self-rotating head with contactless oil brake. Just
like all the other heads in the FV series, this head does not have a cross-spray
pattern but a vertical spray pattern. The nozzle displacement is 15 degrees per
revolution, which means it goes through a complete cycle after 24 revolutions.
The spray distance per revolution at 1 metre away is 26 centimetres. The
rotation speed depends on the operating pressure, water flow rate, nozzle
position, oil viscosity, the brake material and the type of oil used.