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 sensor system comprising a housing having an inlet aperture through which fluid enters the housing and a conditioning material in the housing, the conditioning material being adapted to control levels of a substance within the housing. The sensor system comprises a sensor for analysing the fluid in the housing. The sensor system comprises circulation means which is configured to alternate circulation of fluid within the housing between a sensing fluid path in which the fluid is analysed by the sensor and a second fluid path in which the fluid flow is conditioned. A method for analysing fluid in a housing using a sensor is also provided.

A sensor system comprising a housing having an inlet aperture through which fluid enters the housing and a conditioning material in the housing, the conditioning material being adapted to control levels of a substance within the housing. The sensor system comprises a sensor for analysing the fluid in the housing. The sensor system comprises circulation means which is configured to alternate circulation of fluid within the housing between a sensing fluid path in which the fluid is analysed by the sensor and a second fluid path in which the fluid flow is conditioned. A method for analysing fluid in a housing using a sensor is also provided.

A resistivity regulating apparatus includes: a gas dissolving device that causes a regulating gas to dissolve in a liquid targeted for resistivity regulation to generate a treated liquid in which the regulating gas is dissolved in the liquid, the regulating gas being used to regulate a resistivity of the liquid; and a buffer tank to which the treated liquid discharged from the gas dissolving device is fed.

A resistivity regulating apparatus includes: a gas dissolving device that causes a regulating gas to dissolve in a liquid targeted for resistivity regulation to generate a treated liquid in which the regulating gas is dissolved in the liquid, the regulating gas being used to regulate a resistivity of the liquid; and a buffer tank to which the treated liquid discharged from the gas dissolving device is fed.

Disclosed is a throttle including: an upstream and downstream flanges; a flexible sheath that extends therebetween; a plurality of sets of shape memory alloy wires, extending between the flanges, that are (i) circumferentially aligned about the flanges; and (ii) exterior to the flexible sheath; and (iii) configured to contact an outer boundary of the flexible sheath, wherein: a first set of the plurality of sets of shape memory alloy wires form a first profile when exposed to a first temperature, causing the flexible sheath to form the first profile having a first internal diameter; and a second set of the plurality of sets of shape memory alloy wires form a second profile when exposed to a second temperature that is lower than the first temperature, causing the flexible sheath to form the second profile having a second internal diameter that is smaller than the first internal diameter.

A valve assembly using at least two pressure-sensitive leaky check valves has a non-linear flow-rate versus pressure-drop relation. A method for optimizing such a valve assembly is capable of determining a minimum required number of such valves and outputting the material parameters of each valve. The valve assembly and method allows for arbitrary flow control, which has numerous applications such as within drug delivery, food processing, and industrial flow control. The valve assembly is completely passive, i.e. there is no need for a feedback network. The flow control is achieved using only fluid-structure interactions.

According to an embodiment of the disclosure, an apparatus for a flow of fluid includes a first and a second element that form an exponentially changing restriction between them for a flow of a fluid. At least one of the first and second elements is configured to move in response to changing pressures to change the restriction. One of the first and second elements includes a wall with one or more cutouts that have an admittance that changes exponentially with respect to the movement of the first or second element.

A device for limiting or keeping constant a quantity of fluid flowing therethrough, includes: a housing with a front chamber and a rear chamber; a partition arranged in the housing with two or more openings; and a flow limiting element arranged in one or both openings. The flow limiting element includes a housing provided with an inlet, an outlet and a throughflow opening; and a resilient plate-like valve element mounted in the housing, substantially able to close the throughflow opening by resilient movement in the direction of a valve seat arranged in the housing adjacently of the throughflow opening. The valve element is fixed on one side and can move resiliently on the opposite side in the direction of the valve seat. A mould produces one or more injection-moulded products. The injection-moulded product is a flow limiter for limiting the force of the flow of a fluid flowing therethrough.

A vent limiting device adapted to be operably coupled to an exhaust vent of a fluid regulator. The vent limiting device includes a housing, a poppet disposed in the housing, and a retaining element arranged to retain the poppet in the housing. The housing has a fluid passageway extending between a fluid inlet and a fluid outlet. The poppet is movably disposed in the housing, responsive to pressure at the fluid outlet, to control fluid flow through the fluid passageway. The housing includes one or more retaining features that engage the retaining element to retain the retaining element in the housing.