Plumbing apparatus

A drainage apparatus for a washing vessel, the drainage apparatus comprising:

• a hollow body having a body inlet adapted to be connected to an outlet of the washing vessel and a body outlet adapted to be connected to a soil stack;
• a barrier located between the body inlet and the body outlet, the barrier comprising a vertically oriented barrier pipe housed within a vertical portion of the body, wherein an annular bypass is defined between the barrier pipe and the vertical portion of the body, and wherein the barrier pipe is movable between a fill position in which a lower end of the barrier pipe provides an annular seal such that the barrier pipe prevents fluid flow from the body inlet to the body outlet and a drainage position in which the barrier pipe permits fluid flow from the body inlet to the body outlet;
• and
• wherein, when in use, when the barrier pipe is arranged in the fill position, the annular bypass is arranged relative to the vertical portion of the body to receive fluid being prevented from flowing through the body while the washing vessel is being filled, and when an overflow condition is reached, water within the annular bypass is permitted to flow over an upper edge of the barrier pipe through an open-sided mechanism, into and through the barrier pipe, to prevent over flow of the washing vessel during filling;
• wherein, when the barrier pipe is raised from the body outlet, free-flowing water is permitted from the washing vessel through the inlet to the outlet;
• and
• wherein the barrier pipe is actuable between the drainage position and the fill position by an actuator and an actuator mechanism, wherein the actuating mechanism comprises a first portion and a second portion, wherein the first portion defines an external helical profile and the second portion defines a complementary internal profile, wherein rotation of the actuator causes engaging rotation of the first and second portion which moves the barrier pipe between the fill position and the draining position.