A nozzle of or for a servo valve comprises a nozzle element having a fluid outlet at a first axial end and a tubular body extending from the first end to an opposed, second axial end. The nozzle further comprises a plug element mounted in and closing the second axial end of the tubular body, thereby defining an internal cavity within the tubular body. One or more openings are formed through the tubular body to fluidly communicate with the internal cavity. A filter may be mounted across the internal cavity at a position axially intermediate the openings and the fluid outlet.

A pneumatic valve arrangement for a pneumatically operated field device, such as a control device, of a processing plant, such as a chemical plant, a foodstuff processing plant, a power plant or the like is disclosed. The valve arrangement may include an air supply conduit for receiving pressurized air from a source of pressurized air, a control air conduit for aerating and venting a pneumatic actor of the field device, and a venting conduit for discharging pressurized air to a pressure sink, such as the atmosphere; a venting valve for opening and/or closing the venting conduit and an aerating valve for opening and/or closing the air supply conduit; and a pivotable carrier lever for common actuation of the aerating valve and of the venting valve, wherein the carrier lever holds the venting valve in its closed position while it opens the aerating valve from its closed position.

A single stage flapper type servovalve comprises a valve housing comprising a bore, a pair of opposed nozzles arranged in the bore and a flapper element arranged between the pair of nozzles. The valve housing further comprises a plurality of fluid ports for communicating a working fluid to and from the nozzles and in fluid communication with the housing bore. The valve housing and the nozzles are both made from a stainless steel material.

An adjustable electro-pneumatic converter or transducer based on the nozzle/baffle plate principle is proposed. A defined roughness (Rz) of the baffle plate surface can prevent the occurrence of Bernoulli forces at output pressures close to the initial pressure, i.e. when the exhaust nozzle (140) is almost completely closed by the baffle plate (100). The system thus becomes more dynamically controllable under these conditions. Such a converter can be used to control any consumer system, e.g. air power amplifiers for electro-pneumatic positioners.

A transducer for a connection to a fluid pressure source having a mechanism for setting a pneumatic output by way of an electrical input signal. The transducer provides a lower housing assembly and an upper housing assembly. The lower housing assembly comprises lower housing configured to receive a supply nozzle. The supply nozzle fluidly communicates with a supply port and intermittently fluidly communicates with an output port of the lower housing through an internal fluid passageway. The upper housing assembly comprises an upper housing configured to receive a coil and an armature such that the upper housing, coil and armature define a latching electromagnetic circuit that provides alternating contact of the armature with the supply nozzle of the lower housing assembly.

The present invention controls the pressure and flow rate of fluid, in order to obtain uniform performance, configure a closed loop magnetic circuit so as to include an electromagnet, a flapper, and a yoke material, and elastically deform the flapper itself by Maxwell attractive force generated between a magnetic pole of the electromagnet and the flapper to make the separation distance between the nozzle and the flapper variable. As opposed to a rigid flapper structure that swingably moves around a supporting point, like a conventional servo valve, the electromagnet, the magnetic pole, the nozzle, the flapper, and the like are arranged such that a change in magnetic gap directly leads to a change in air gap.

A hydraulic stage includes a hydraulic element located between and sealing a first and second chamber, wherein the first chamber comprises at least one aperture through which fluid is arranged to flow into or out of the first chamber; and at least one piezoelectric element which is positioned adjacent to the at least one aperture and is arranged to deform in response to an applied potential difference such that it blocks or obstructs the at least one aperture to a varying degree according to the level of deformation, so as to control fluid flow into or out of the first chamber. The level of deformation of the piezoelectric element thus reduces or increases an effective size of the inlet or outlet aperture to which it is adjacent, restricting or permitting an increase in fluid flow accordingly.

An electropneumatic switch valve includes a pneumatic circuit to a pressurized fluid source, an electromagnetic circuit coupled to the pneumatic circuit, and a control module connected to the electromagnetic circuit. The control module provides a first control signal inducing a first state of the pneumatic circuit, a second control signal inducing a second state of the pneumatic circuit, a third control signal inducing a third state of the pneumatic circuit, and a fourth control signal inducing a fourth state of the pneumatic circuit.

The present invention controls the pressure and flow rate of fluid, in order to obtain uniform performance, configure a closed loop magnetic circuit so as to include an electromagnet, a flapper, and a yoke material, and elastically deform the flapper itself by Maxwell attractive force generated between a magnetic pole of the electromagnet and the flapper to make the separation distance between the nozzle and the flapper variable. As opposed to a rigid flapper structure that swingably moves around a supporting point, like a conventional servo valve, the electromagnet, the magnetic pole, the nozzle, the flapper, and the like are arranged such that a change in magnetic gap directly leads to a change in air gap.

The positioner having an air circuit including magnetism generating portions producing magnetism based on a current in accordance with a difference between a valve opening setpoint of a regulator valve and a measured value for the valve opening, to generate a pneumatic signal wherein the air pressure is adjusted based on the magnetism produced by the magnetism generating portions, where this pneumatic signal is supplied to an operating device of the regulator valve, where the magnetism generating portions are connected in parallel, and including a plurality of coils connected through magnetically additive coupling.