A device and method to improve accuracy of a water meter where a fluid is introduced into a valve assembly having an external casing. The fluid contacts a toggle stopper having a shaft, plate, and guides. A calibrated spring positioned around the shaft in contact with the plate assesses if the desired fluid meets a predetermined pressure. If yes, the calibrated spring compresses thereby toggling the plate within the chamber to allow desired fluid to enter the chamber. If no, the calibrated spring remains in an expanded state to seal the valve assembly. Upon such seal, there is an equalizing of both the desired and undesired fluids to the same pressure by decreasing the volume of the undesired fluid, causing the calibrated spring to compress and reopen.

A mechanical shutdown valve for preventing an over pressure condition is described. A valve body has an inlet, an outlet, and a channel extending from the inlet to the outlet. A valve seat and a diaphragm are positioned in the valve body. The diaphragm controls a fluid flow through the valve body. A mesh is coupled to the diaphragm such that the mesh and the diaphragm separate an upstream portion of the channel from a downstream portion of the channel. The mesh extends from the diaphragm to an inner surface of the valve body and limits fluid flow between the diaphragm and the valve body. A spring biases the diaphragm towards the open position. A characteristic of the spring determines a differential pressure threshold between the upstream portion of the channel and a downstream portion of the channel at which the diaphragm engages the valve seat.

A hydraulic pump is described, comprising at least one inlet duct for a fluid, at least one outlet duct for the fluid and at least one pumping unit interposed between the inlet and outlet ducts. At least one multifunction valve is interposed between the inlet duct, upstream of the pumping unit, and the outlet duct, downstream of the pumping unit, which valve is configured to divert the flow of fluid from the inlet duct to the outlet duct without the fluid flowing into the pumping unit. The multifunction valve comprises a valve body that defines an inner bypass channel in which a shutter element is axially movable, an actuator member operatively associated with the shutter element and configured to move it from a closing position to an opening position of the bypass channel, and an elastic contrast element operatively associated with the shutter element and configured to keep it in the first closing position of the bypass channel when such shutter element is not actuated by the actuator member. The actuator member consists of a bias spring manufactured with a shape memory alloy, configured to move the shutter element from the first closing position to the second opening position of the bypass channel when a predefined temperature value is reached.

Valves may include an opening sized and shaped to permit a subject fluid to flow through the opening when the opening is unobstructed. A heat exchange element may be located proximate to the opening, the heat exchange element positioned and configured to induce a localized phase change in the subject fluid to form and unform a solid plug from the subject fluid around at least a portion of the heat exchange element. A heat transfer rate of the heat exchange element may be variable to control a rate of flow of the subject fluid through the valve by controlling a size of the solid plug from the subject fluid.

Valves may include an opening sized and shaped to permit a subject fluid to flow through the opening when the opening is unobstructed. A heat exchange element may be located proximate to the opening, the heat exchange element positioned and configured to induce a localized phase change in the subject fluid to form and unform a solid plug from the subject fluid around at least a portion of the heat exchange element. A heat transfer rate of the heat exchange element may be variable to control a rate of flow of the subject fluid through the valve by controlling a size of the solid plug from the subject fluid.

A gas dosing apparatus is provided that includes an inlet configured to receive gas, and a directional control valve connected to the inlet and having a first position and a second position. The gas dosing apparatus also includes a fixed volume reservoir connected to the directional control valve and receiving gas from the inlet, via the directional control valve, while the directional control valve is in the first position. The gas dosing apparatus further includes an outlet connected to the directional control valve and outputting a gas dose received from the fixed volume reservoir, via the directional control valve, while the directional control valve is in the second position

A flow regulator for regulating a flow rate of water within at least a section of a water system, such as an irrigation system, includes a base member and piston member. The piston member is movable relative to the base member and includes at least one notch through which water can flow when passing through the flow regulator. Movement of the piston member towards and away from the base member, respectively, decreases and increases an area of the notch through which water can flow. An orifice member detachably coupled to the piston member and having an orifice member aperture through which all water flowing through the flow regulator must pass limits the cross-sectional area of an interior water passage within the piston member.

A manifold for an air massage system of a tub may have a housing defining an inner cavity having an air inlet configured to be pneumatically connected to a pressure source. Air outlet(s) is pneumatically connected to one or more outlets of the tub. A check valve(s) is in the inner cavity of the housing, the at least one check valve being positioned between the air inlet and the at least one air outlet relative to an air flow through the housing, the at least one check valve allowing fluid communication from the air inlet to the at least one air outlet and blocking water from flowing from the at least one air outlet to the air inlet. A width of the manifold is less than a height of the manifold.

A time delay valve includes a switching valve that switches between a first position and a second position; an urging member that urges the switching valve toward the first position; a driving mechanism that urges the switching valve toward the second position located opposite the first position in the presence of the pressure of a pilot fluid being supplied: a pilot flow channel that introduces the pilot fluid to the driving mechanism; and a delaying mechanism that delays the switching timing of the switching valve. The delaying mechanism includes a first throttle valve provided on the pilot flow channel, a compensation mechanism that urges the switching valve toward the first position in the presence of the pressure of the pilot fluid being supplied, and a compensation flow channel that is branched from the pilot flow channel to introduce a portion of the pilot fluid to the compensation mechanism.

A thermal relief device (1) is described comprising a housing (2) having an inlet (3) and an outlet (4) connected by a relief channel (5). Such a thermal relief device should have a simple construction. To this end a microporous structure (10) is arranged between inlet (3) and outlet (4).