The present invention relates to improvements of valves of the cartwheel type, with receptive arrangements incorporating the valves, which comprise a component of elastomeric material in the form of a cartwheel fastened by means of the external ring to the valve case. The invention comprises a central plug connected by rods to the external ring and, normally, when used in two-way casings (with only one inlet and one outlet), the valve acts as a unidirectional valve. When used in a three-way casing, or a casing with more than three thereof, the valve can act to seal off and let through a flow of fluid on either side of the valve, alternately, depending on the fluid-circulation design choice.