Abstract: A fully sealing butterfly valve throttles flow rates through a flow channel and completely ceases flow. A throttle plate rotates into a close position and then moves axially to seat against a seal. The axial movement directly corresponds to rotation of an actuator shaft to improve valve control for the entire range of throttle plate movement from a full open position to a seal position. Additionally, the present butterfly valve employs a self-centering throttle plate adapted to float within the valve central bore. The throttle plate adjusts its positioning about an annular seal to achieve an effective seal entirely around its circumference.

Abstract: A portable sample cylinder assembly is provided for transporting a fluid. The sample cylinder assembly includes a housing defining in part an internal fluid chamber, a first end cap at one end of the housing, and a second end cap at an opposing end of the housing. At least one of the end caps includes a stop surface and an annular groove. An elastomeric seal is positioned within the groove for static sealing between the end cap and the housing. The end of the housing includes an end surface for metal-to-metal engagement with the stop surface, and a compressional surface for applying a compressional force to the elastomeric seal in response to axial movement of the end surface toward the stop surface. A plurality of connector rods may be used to controllably move the end cap axially toward the housing and thereby compress the elastomeric seal to reduce the permeability of the seal.

Abstract: A interconnection system for coaxial fluid tubing includes zero-clearance connectors having a metallic innner gasket for sealing an inner passageway for a first fluid and having a elastomeric outer gasket for sealing an outer passageway for a second fluid. The elastomeric outer gasket forms a fluid-tight seal as the connectors are tightened. Further tightening of the connectors engages and seals the metallic inner gasket. Both straight tubing sections and elbows are constructed in a factory setting so that the completed sections can be assembled at a job site without cutting or welding.

Abstract: A sampling pump is provided suitable for pumping a discrete quantity of either a liquid or a gas per pump stroke from a flow line to a sample vessel. An operator unit drives a piston within the pump bore, and controls the stroke of the piston and thus the quantity of fluid pumped per stroke. A balanced check valve mechanism controls flow from the pump bore to the pump outlet port, and is provided within and carried by the piston. Line pressure acts on the operator end of the piston to assist the operator in driving the piston during its power stroke. A manifold may be secured to the pump body, and has a flow path therein which is in communication with the inlet port to the pump bore. The pump may also be used for injection purposes to introduce a selected quantity of fluid to a high pressure line.

Abstract: A voltage reference circuit employs a bandgap cell to establish a voltage reference, stabilized relative to the bandgap voltage of silicon, and a compensation circuit for compensating non-linear temperature dependence of the bandgap stabilized voltage reference. A two or three transistor type bandgap cell may be employed to establish the bandgap reference voltage along with a voltage divider network to adjust the output reference voltage relative to the bandgap voltage of silicon. The compensation circuit preferably employs a compensation resistor in the resistor divider network, and a switching circuit for switching current therethrough. This provides empirically determined adjustments to the output reference voltage by switching current through the compensation resistor in accordance with predetermined temperature thresholds.

Abstract: A method for forming a dielectrically isolated semiconductor devices on a semiconductor substrate. An epitaxial layer is grown on a wafer having a thin buried oxide layer. Trench regions are etched through the epitaxial layer to the underlying oxide layer. A dielectric isolation layer is formed on the sidewalls of the trench regions so as to isolate an active region of the epitaxial semiconductor material. The trenches are etched to the underlying semiconductor substrate and the semiconductor material is selectively epitaxially regrown in the trench regions. Semiconductor devices are formed in the isolated active regions. Contacts are made to the active regions of the semiconductor device and to the wafer substrate through the epitaxially regrown trench regions.

Abstract: A method for generating the characteristics of a set of colors involves selecting at least two, and typically more reference colors. Each of the selected reference colors is described by a set of color characteristic data indicating the reflectance of each color at each of a set of predetermined wavelengths; and descriptions of the intermediate color samples are generated by computer the relative proportions of each base color which characterizes each intermediate color and calculating a reflectance value at each wavelength for the color to be generated proportionate to the reflectance values for each base color at the corresponding wavelength. A set of color samples is created as a result of the method for generating the characteristics of the colors and arranged in a geometry indicative of the method.

Abstract: Improved methods and apparatus are provided for structurally interconnecting an instrument manifold with a differential pressure assembly having a pair of tapered NPT threaded outlet ports each adjoining an exterior body surface. First and second connector flanges are provided each having a through passageway for transmitting a pressure signal from the corresponding NPT outlet port in the differential pressure assembly to an inlet port in an instrument manifold. Each connector flange includes a tapered threaded end, a flange end, and a threaded portion fixed between the threaded end and the flange end. The apparatus also includes first and second stabilizer members, and first and second tensioning nuts for exerting a compressive force on the stabilizer members such that the stabilizer members will transmit substantially all radially-directed forces to the differential pressure assembly.

Abstract: The circuitry of the present invention taps a DS0 data stream and outputs a timing signal to drive terminal multiplexers. Even if the data bit stream is lost, the present invention continues to provide proper clocking signals. A composite clock (bit and byte clock) is provided by the present invention with the bit clock at 64 KHz and the byte clock at 8 KHz in the preferred embodiment. To avoid the problem of phase shift over long distances (limiting cable length) the present invention phase adjusts the digital bit stream clocking signal with a 360 degree delay, giving the appearance of advancing the signal in phase. An additional delay of one frame width is applied to the signal. A negative phase delay equivalent to cable runs from 0-1500 feet in 500 foot increments is also applied. In the preferred embodiment, a shift register is tapped in reverse order to accomplish this phase delay.

Abstract: A piston-type portable sample cylinder is provided suitable for obtaining and transporting a liquified petroleum gas sample taken from a flow line. A piston slidable in a cylinder creates an increasing volume for the sample, and displaces an opposing inert gas maintained in the sample cylinder at a present pressure. A toroidal mixing element has an outer diameter approximating the inner diameter of the cylinder, and slides over a cylinder projection on the piston to minimize voids when the sample cylinder is empty. The piston may be provided with a selectively adjustable seal for maintaining sealing integrity over a long life, with or without the use of lubricants. Magnets on the piston for activating external magnetic trip flags may be contained in a nylon protector ring. Precision fill measurements may be obtained from a sight gauge including a biased coiled tape mounted within the pressurized inert gas cavity of the sample cylinder and secured to one end of the piston.

Abstract: Improved methods and apparatus are provided for structurally interconnecting an instrument manifold with a differential pressure assembly having a pair of tapered NPT threaded outlet ports each adjoining an exterior body surface. First and second connector flanges are provided each having a through passageway for transmitting a pressure signal from the corresponding NPT outlet port in the differential pressure assembly to an inlet port in an instrument manifold. Each connector flange includes a tapered threaded end, a flange end, and a threaded portion fixed between the threaded end and the flange end. The apparatus also includes first and second stabilizer members, and first and second tensioning nuts for exerting a compressive force on the stabilizer members such that the stabilizer members will transmit substantially all radially-directed forces to the differential pressure assembly.

Abstract: A piston-type portable sample cylinder is provided suitable for obtaining and transporting a liquified petroleum gas sample taken from a flow line. A piston slidable in a cylinder creates an increasing volume for the sample, and displaces an opposing inert gas maintained in the sample cylinder at a presesnt pressure. A toroidal mixing element has an outer diameter approximating the inner diameter of the cylinder, and slides over a cylinder projection on the piston to minimize voids when the sample cylinder is empty. The piston may be provided with a selectively adjustable seal for maintaining sealing integrity over a long life, with or without the use of lubricants. Magnets on the piston for activating external magnetic trip flags may be contained in a nylon protector ring. Precision fill measurements may be obtained from a sight gauge including a biased coiled tape mounted within the pressurized inert gas cavity of the sample cylinder and secured to one end of the piston.

Abstract: The present invention provides a clock holdover circuit which will provide a replacement clock signal within predetermined parameters independently of time and temperature variations. The circuit of the present invention has only a single component which is time and temperature dependent. By selecting the components parameters to be within the desired tolerances, the accuracy of the circuit is maintained. In the present invention, digital circuitry is combined with an accurate local crystal frequency source to provide a replacement clock signal. The present invention allows phase consistency upon loss of a reference clock signal as well as on return of the reference clock signal. A reference clock signal is phase locked to a VCO to produce a desired output. The frequency of the output is compared to a local frequency standard to generate an offset frequency used to control a frequency synthesizer. The offset frequency is digitally stored.

Abstract: An improved capacitance manometer includes a thin, electrically conductive diaphragm fixedly mounted to a housing. The diaphragm separates a first chamber that is subjected to a reference pressure from a second chamber that is subjected to a pressure that is to be measured relative to the reference pressure. The diaphragm flexes in response to a pressure differential between the two chambers. The diaphragm comprises one electrode of a variable capacitor. A second electrode of the variable capacitor is provided by a fixed electrically conductive area mounted on a ceramic disc or other fixed electrode support. The ceramic disc is mounted within the housing so that the electrically conductive area on the ceramic disc is proximate to and spaced apart from the diaphragm in generally parallel relationship to the diaphragm when the diaphragm is in a substantially relaxed condition (i.e., not flexed by a pressure differential).

Abstract: A differential variable gain transconductance amplifier suitable for but not limited to applications requiring operation with a power supply of less than 1.0V. The circuit is suitable for fabrication by integrated circuit technology and is composed of three major blocks: an input stage, a current summing gain control stage, and an output stage. The differential input stage is comprised of two identical voltage-to-current converters, with one used as the positive input and the other as the negative input. The current summing stage uses the principal of summation of opposite but equal currents canceling to produce attenuated gain. The output stage converts current into voltage and produces a single ended output.

Abstract: A valve of the outside seal and yoke variety is provided, with a seal between a bonnet base and a valve body being axially spaced between a valve seating member and mating threads on the valve body and bonnet base. An end of at least one packing bolt is positioned within a cavity formed within the valve body, and prevents the bonnet base from unthreading from the valve body. A yoke threaded to the valve stem is rigidly secured to the bonnet base by a pair of yoke bolts and intermediate supports, and prevents inadvertent rotation of the packing bolts. The assembly technique of the present invention provides an inexpensive yet reliably OS&Y valve with all desired structural components being rigidly connected. The bonnet assembly of the present invention may be utilized with a conventional valve body and pocket design, thereby substantially increasing versatility and reducing manufacturing costs.

Abstract: An apparatus and method control the pressure in a system by continuously measuring the pressure and comparing it to a desired set pressure. The apparatus and method record a history of the measured pressure as a function of time and calculate the rates at which the pressure changes. The rates at which the pressure changes are recorded and the rate at which the rates change is also calculated to determine the rate at which the apparatus and method can vary the rate of change of pressure. The apparatus and method calculate the amount of time required to reach the desired set pressure and compare it to the amount of time required for the rate of change of the pressure to become zero and adjust the flow of a gas in the system so that the desired set pressure is achieved at substantially the same time as the rate of pressure change becomes zero.

Abstract: A circuit status indicating device is used to monitor separate circuits to indicate their on/off status. Each circuit conducts an AC operating signal when switched to "on" status and an AC non-operating signal when switched to "off" status. The AC non-operating signal can be zero or some fraction of the AC operating signal, depending on the type of contact switches used in the circuit being monitored. A separate LED is provided for each circuit monitored. A separate AC input signal corresponding to one of the AC operating and non-operating signals in each monitored circuit is received and compared with a modified AC reference signal to produce an AC comparison output signal. A DC reference signal is compared with the AC comparison output signal and produces a DC output signal when the AC comparison output signal exceeds the DC reference signal.

Abstract: Silicate minerals, including asbestos fibres, are rendered less harmful by forming metal-micelle polymer coatings on the silicate. A metal-micelle polymer coating is formed on a silicate by contacting a silicate mineral, such as asbestos, with a metal-weak base-strong acid aqueous ion system, or a metal-strong base-weak acid ion system. In these systems the metal is selected from the group consisting of manganese, chromium, cobalt, iron, copper, aluminum and mixtures of these metals. The product of reacting asbestos fibres with these systems is less irritating to living cells than asbestos fibres and also has substantially the same physical and chemical properties as asbestos fibres and can thus be substituted for asbestos fibres in most technological applications.

Abstract: In separation of a stream of oil, gas and water into the constituents thereof in a horizontal heater-treater vessel having a gas separation chamber and an emulsion treating chamber, the stream is caused to flow downward into the gas separation chamber and through an outer secondary heating zone therein to permit gas to separate for upward flow and to cause heated components of the stream to turn to upward flow and thereafter to flow downward through an inner primary heating zone. Common boundaries of the heating zone are defined by an inverted U-shape shroud in the gas separation chamber. Water flows down to the bottom of the vessel from the stream in both the primary and secondary heating zone. Gas flows upward from both the primary and secondary heating zones and an oil-water emulsion flows from the primary heating zone directly into the emulsion treating chamber.