Mks Instruments, Inc.

Paul D Lucas

Jaroslaw Wojciech Pisera

Gordon Hill

Stephen F Bart

Lei Gu

Philip W Sullivan

Kristen Dodds Weight

Chris P Grudzien

Steven D Blankenship

Vladislav Davidkovich

David Brian Chamberlain

John A Denner

Swaminathan Venkatesan

Phillip W Sullivan

Ethan E Mattor

Robert Krmpotich

Sergei Syssoev

Dave Chamberlain

Anthony J Carbone

Jeff Lischer

Ting Huang

Frederick J Luft

John Denner

A capacitive manometer offering improved measurement accuracy is disclosed which includes at least one electrode structure having an inner electrode structure and an outer electrode structure separated by at least one gap, at least one flexible diaphragm having at least one conductive material positioned thereon or integrated therein may be positioned in movable relation to the electrode structure and in proximity to the electrode structure, and at least one non-planar baffle less prone to transient measurement errors having an inner baffle structure and an outer baffle structure separated by at least one baffle orifice positioned distantly from the electrode structure proximate to the flexible diaphragm.

Capacitance manometer with improved baffle for improved detection accuracy

A pressure sensor may measure gas or liquid pressure. A chamber may have an inlet that receives the gas or liquid. A flexible diaphragm may be within the chamber that has a surface exposed to the gas or liquid after it flows through the inlet. A pressure sensor system may sense changes in the flexible diaphragm caused by changes in the pressure of the gas or liquid. A pressure-insensitive sensor system may sense changes in the flexible diaphragm that are not caused by changes in the pressure of the gas or liquid. The pressure-insensitive sensor system may be insensitive to changes in the flexible diaphragm caused by changes in the pressure of the gas or liquid.

Pressure sensor with real time health monitoring and compensation

A valve assembly comprises: a valve body including a passageway through which a first gas can be transmitted through the valve assembly; a valve flow control element movable relative to the valve body between an opened position wherein flow through the passageway is at a maximum flow, and a closed position wherein flow through the passageway is at a minimum flow, the valve flow control element is shaped so that a control gap is provided between the valve body and valve flow control element through which the first gas can flow, and the dimensions of the control gap vary depending on the position of the valve flow control element relative to the valve body; and a gas injector arrangement for selectively injecting a second gas into the control gap when the valve assembly is used to control the flow of the first gas through the passageway. The injection of the second gas when the valve flow control element is at or near its closed position helps minimize condensate being deposited on the valve flow control element, as well as reduce the closed conductance of the valve.

Fluid control valves

One or more reactive gases are introduced to a capacitance manometer at a particular area or areas of the diaphragm between the inner and outer capacitive electrodes so the error-inducing measurement effects of positive and negative bending are neutralized or minimized. Additionally, a guard structure may be used with the electrode structure of the capacitance manometer. The guard structure presents an area that is relatively insensitive to the diffusion of the gas into the diaphragm and the resulting changing surface tension, thus providing increased or optimal stability of the zero reading of the manometer. The guard may also provide electrostatic isolation of the electrodes.

Pressure sensor

A butterfly valve comprises: a body including a valve opening; and a flapper rotatably mounted about a rotation axis so as to be movable relative to the valve opening. The flapper is rotatable at least 180&#xb0; about the rotation axis so that the flapper is movable to at least one fully opened position, at least one fully closed position 90&#xb0; apart from the fully opened position, and a third position, either fully opened or fully closed, 180&#xb0; from the other like position. In one embodiment the flapper is rotatable at least 360&#xb0; about the rotation axis so that the flapper is movable to each of two opened positions 180&#xb0; apart, and two closed positions 180&#xb0; apart from each other and 90&#xb0; and 270&#xb0; apart from each of the fully opened positions. The valve can be easily calibrated and controlled, and cleaned to extend the useful service life between cleanings.

Butterfly valve and system employing same and method for using same field

A pressure control system for controlling pressure of a fluid in a chamber includes a pressure sensor configured to measure the pressure of the fluid in the chamber, and a valve configured to control the pressure of the fluid in the chamber by regulating flow of the fluid from the chamber. The pressure control system further includes a controller. The controller is configured to estimate the volume of the chamber, and to generate a pump speed curve of the valve. The controller is further configured to monitor and modify the pump speed curve so as to maintain a slope of the pump speed curve to at least a minimum value, and to use the modified pump speed curve to adjust the position of the valve in response to pressure measurements by the pressure sensor, so as to maintain the pressure in the chamber at a desired pressure setpoint.

Pressure control system with optimized performance

A valve assembly including a housing having a flow path extending to an outlet and a valve seat in the flow path and around the outlet, a slide plate located in the housing and movable transversely to a longitudinal axis of the flow path between a closed position, in which the slide plate is in contact with the valve seat and blocks flow through the flow path, and an opened position, in which the slide plate allows flow through the flow path, and wherein at least one of the slide plate and the valve seat includes at least one passageway for providing a predetermined amount of conductance between the slide plate and the valve seat when the slide plate is in the closed position.

Valve assembly having improved pump-down performance

A valve assembly including a housing having a flow channel and an annular surface surrounding the flow channel, a slide plate movable to a closed position, and a seal ring positioned between the annular surface and the slide plate. The seal ring includes a first and second sides, a first surface extending between the first and the second sides and facing towards the annular surface of the housing, and a second surface axially spaced from the first surface and extending between the first and the second sides and facing towards the slide plate. The second surface includes a continuous annular sealing portion for contacting the slide plate when the seal ring is biased against the slide plate so that a fluid-tight seal can be formed between the continuous annular sealing portion and the slide plate, and at least one passageway positioned between the annular sealing portion and the second side.

Valve assembly having novel flow characteristics

A valve assembly including a housing having a flow channel, a slide plate movable between a closed position and an opened position, and a seal ring surrounding the flow channel and engaging the slide plate in the closed position and disengaging the slide plate in the opened position. The seal ring has a plurality of bores aligned, respectively, with holes formed in an adjacent surface of the housing. Each bore includes an undercut defining a lip. A plurality of fasteners are arranged in the holes of the annular surface of the housing and extend into the corresponding bores of the seal ring. Side walls of the fasteners include slots, which catch on the lips of the bores of the seal ring when the fasteners are inserted into the bores of the seal ring, and the seal ring is rotated.

Seal ring for pendulum valve assembly

A valve assembly including a housing having an opening defined by a valve seat, a valve body movable within the housing between a completely opened position disengaged from the valve seat and a completely closed position engaging the valve seat, and a sleeve movable longitudinally along, and rotatably about, a longitudinal axis. The sleeve is connected to the valve body so that the valve body can rotate and move longitudinally with the sleeve. One of the housing and the sleeve includes a cam surface, and the other of the housing and the sleeve includes a cam follower received by the cam surface. A rotatable shaft is in threaded engagement with the sleeve so that rotation of the shaft causes at least one of rotation and longitudinal movement of the sleeve against the cam follower.

Pendulum valve assembly

A pressure transducer assembly includes a first body, a second body, a diaphragm, and an electrode. The diaphragm is mounted between the first and second bodies. The first body and the diaphragm form a first chamber. The second body and the diaphragm form a second chamber. The electrode is disposed in the first chamber. A portion of the diaphragm flexes in a first direction in response to pressure in the first chamber being greater than pressure in the second chamber. A portion of the diaphragm flexes in a second direction, opposite the first direction, in response to pressure in the second chamber being greater than pressure in the first chamber. A capacitance between the electrode and the diaphragm is representative of a difference between the pressures in the first and second chambers. In some embodiments, the electrode is suspended from a hub and spoke mounting. In some embodiments the electrode is entirely metallic. In other embodiments, the electrode includes a ceramic disk with a conductive film formed on the disk and the disk is coupled to the housing with a ceramic rod. In some embodiments, the transducer also has a low thermal coefficient of expansion member connected to the housing for reducing warping in response to temperature changes. In additional embodiments, the disk includes a groove that reduces the effects of temperature variations on a ceramic electrode.

Capacitive based pressure sensor design

The disclosed mass flowmeter includes a section defining a passageway and a laminar flow element disposed within the passageway so as to define a laminar flow channel within the passageway. The maximum cross sectional dimension of the laminar flow element is smaller than the maximum cross sectional dimension of the passageway. In one embodiment the flowmeter includes a device for mounting the laminar flow element within the passageway so that the laminar flow element contacts at least a portion of an inner surface of the passageway so that various sized laminar flow elements can easily and reliably be substituted for one another so as to select the mass flow rate through the channel. In a second embodiment the laminar flow element includes two support segments which are fitted within the passageway and support a central segment which defines within the passageway the laminar flow channel. In the latter embodiment the support segments can be fixed within the passageway in various ways, including providing the support segments as end segments and forming end slots in the end support segments so that wedging pieces, in the form of balls or pins, for example, can be inserted so as to spread the slotted portion of each end segment apart so as to hold the laminar flow element firmly in place. In another embodiment the position of at least a portion of the laminar flow element is adjustable between one of two positions so that the cross sectional shape of the channel can be modified so as to modify the flow rate through the channel.

Mass flowmeter and laminar flow elements for use therein

A multi-channel mass flow transducer has a single laminar flow element in a primary fluid flow path and multiple secondary flow paths in parallel with and in fluid communication with the primary flow path. Flow restriction elements are disposed in one or more of the secondary flow paths to establish different flow rate measurement 'channels' having particular flow rate ranges. The multi-channel transducer of the present invention is capable of measuring fluid flow rates over an extended range and eliminates the need for multiple transducers to measure varying fluid flows.

Growing community of inventors

Melrose, MA, United States of America

Paul D Lucas