Abstract: A valve assembly (110) having a housing (124) into which are provided a first port (112), a second port (114) and a third port (116), and in which are located a first movable member (126), a second movable member (132) and a third movable member (152), the first movable member (126) being movable between a first position which causes the second movable member (132) to close the first port (112) to prevent any substantial flow of fluid through the first port (112), whilst the second (114) and third (116) ports remain open, a second position which causes the third movable member (152) to close the third port (116) to prevent any substantial flow of fluid through the third port (116), whilst the first (112) and second (114) ports remain open and flow of fluid between the first (112) and the second (114) part is permitted, and a third position which causes the second movable member (132) to close the first port (112) and the third movable member (152) to close the third port (116) to prevent any substantial flow