Abstract: A fluid storage tank having opposite upper and lower ends, a tank wall extending between the ends, and an internal tie assembly to assist the tank wall to resist hydrostatic pressure induced by fluid in the tank, the internal tie assembly comprising an elongate tie having spaced apart couplings, and a plurality of retaining formations fixed to, or integrally formed on, an inner surface of the tank wall, wherein the couplings of said tie are arranged to be received in respective ones of said retaining formations to connect said tie to said tank wall so that said tie is able to resist outward deformation of said tank wall.

Abstract: Fittings for a water storage tank are disclosed. The fittings comprise an inlet sub-system (3) for allowing the passage of water into the tank, an outlet sub-system (47) for allowing the passage of water from the tank; and an overflow outlet sub-system (77) for allowing the passage of water from the tank.