Abstract: A power circuit for a precipitator utilizes a pair of silicon controlled rectifiers (SCR's) which are triggered by detecting the zero crossover of a power signal. The power transmitted through the SCR's is determined by the time period from the detection of the zero crossover to the generation of the trigger signal. Power signals are typically subject to noise which interferes with the detection of the zero crossover. Filters are provided for reducing the noise interference but function without altering the phase relation of the zero crossover of the filtered signal in respect to the unfiltered power signal. A pulse train of higher frequency than the power signal is generated to provide a plurality of triggering pulses for the SCR. Further, phase control signals are generated for each SCR to prevent the generation of trigger pulses when the SCR's are reverse biased.

Abstract: To provide reduction in temporary conditions of excess load on the thrust bearing, a labyrinth positioned contiguous to a leakage aperture in the high pressure side of a single stage overhung compressor rotor affords controlled leakage to a venting circuit in communication with a lower pressure system. A pressure switch responsive to pressure levels in the venting circuit prevents compressor start at pressures above the set point of the switch while a backpressure valve in the venting circuit when operative maintains a predetermined pressure level therein. When the thrust bearing is operating at speeds sufficient to enable acceptance of the load imposed by compressor pressure, an override solenoid valve serves to close the backpressure valve and operably shut the venting circuit.

Abstract: Bourdon tubing is constructed from metal strip by roll forming the strip into a desired tubular cross section with the opposed edges abutting longitudinally at a location in the cross section at which contemplated operational stresses are predetermined to be relatively low. After continuously welding the edges in a pressure-tight relation, the tubing can be shaped along its length into a Bourdon tube configuration without need for further metallurgical mill processing.

Abstract: A generally cylindrical plug is adapted for a snug fit in a socket bore communicating with the inlet of a pressure gauge. The plug includes an upstream portion and an axially contiguous downstream portion, each cooperating with the surrounding surface of the socket bore to define a continuous flow path communicating inward to the sensing unit of the gauge. Through the upstream portion, the flow path is annular in cross-section between the plug surface and the bore surface while the downstream portion defines a helical flow path communicating with the open bore downstream thereof. Dimensionally critical in the relationship of the flow path defined in the upstream portion, versus the flow path defined in the downstream portion is the requirement that the former have a clearance dimension relatively smaller than the minimum clearance dimension through the cross-section of the latter.

Abstract: A pressure gauge having a rotatably secured Bourdon tube, and a dial plate arcuately displaceable for effecting zero calibration of the gauge includes a rotationally presettable key for registered placement within a key-slotted receptacle in which the gauge is to be utilized. Keying is provided by a simulated Y-shaped washer mounted in an annular groove on the gauge stem and arcuately secured post-calibration at a predetermined angular setting from a reference point on the gauge dial.

Abstract: The stem connection of a back connected gauge instrument placed extending partially through an opening in a panel wall is received in an aperture of an elongated clamp plate adapted to span the instrument parallel to the backside of the panel. A keyed recess in communication with the plate aperture is adapted to interlock with a cooperative surface on the gauge stem at a predetermined location longitudinally spaced behind the gauge. A foot of a leg extending integrally from the plate at one end thereof toward the backside surface of the panel cooperates with a similarly extending preassembled thumb screw extending transversely through the plate at the opposite end to effect mounting. The thumb screw also serves to adjustably draw and secure the gauge into its mounted position.

Abstract: For limiting leakage of a high pressure buffer gas supply about the gas seal in a turbo compressor, the sliding face on the inward diameter of the seal includes a plurality of axially spaced annular O-ring seals positioned in tandem staged sealing relation thereat. Communicating from between each juxtaposed pair of O-ring seals is a bleed port enabling inter-O-ring pressure to be controlled for any overall pressure differential that is encountered.

Abstract: An active voltage divider providing output voltage overload protection operably effective in the event failure of the primary resistor should occur. Comprising the divider circuit is a differential amplifier operable as an integrator, a first pair of grounded diodes providing primary over-voltage protection for a first summing junction of the amplifier and a second pair of grounded diodes providing voltage backup protection for a second summing junction of the amplifier.

Abstract: An electrically conductive ring is secured to a rotating shaft electrically insulated therefrom at or near the shaft location at which the maximum amplitude of lateral vibration is anticipated. Providing a transverse magnetic field contiguous to the ring periphery is at least one pair of spaced magnets. The magnetic field imposed by the magnets is effective when vibrationally penetrated by the ring to induce an electrical current in the ring causing energy dissipation that repels the amplitude of the shaft.

Abstract: A leak-proof joint between a stainless steel gauge case and the brass socket of a pressure gauge includes a stainless steel sleeve brazed to the socket in the area of the case connection for enabling the gauge case to be welded thereto.

Abstract: A high pressure rotary plug valve having at least one groove in the housing to provide a flushing/lubricating flow of innocuous fluid between the housing and rotary plug thus preventing fine solids build-up and decrease wear.

Abstract: An elongated actuator pin in a pressure gauge extends from a fixed end to a free end to interact with the amplifier for enabling pivotal motion thereof to translate Bourdon displacement to an output pointer. A clamp slideably mounted on the actuator pin is operatively effective when set at a selected location along the pin length to variably offset the free end of the pin from its longitudinal axis for obtaining correct calibration adjustment of the gauge.

Abstract: A valve, such as a butterfly valve having an offset closure vane and stub shafts for operating the vane in the flow passage of the body, has all exposed and/or potentially vulnerable metal surfaces encapsulated in a corrosion-resistant polymeric plastic coating. Providing bearing support for the vane drive shaft are a pair of spaced apart journal bearings located in the shaft bore in a shrink fit relation to the coating thereat.

Abstract: Method and apparatus for constructing a pressure gauge in which the socket and at least a portion of the movement for driving the pointer are initially formed integral of a molded polymeric plastic composition.

Abstract: To reduce the cost of construction and avoid alignment problems of its component parts, a non-welded construction of mast discharge electrode, as used in an electro-precipitator, comprises a tube having holes passing transversely therethrough, cross members frictionally secured in said holes, and at least two wires extending parallel to said tube and passing through holes in said cross members, the wires being secured in the holes also by friction. The cross members may be knurled so as to be gripped in the tube holes, the latter preferably being formed by means of a punching operation. The cross members may be crimped frictionally to secure the wires. The provision of a non-welded construction particularly at the wires avoids weakening the wires because of the welding, and distortion arising from the heat of welding. The cross members may alternatively be welded to the tube if desired.

Abstract: The stem connection of a back connected gauge instrument placed extending partially through an opening in a panel wall is received in an aperture of an elongated clamp plate adapted to span the instrument parallel to the backside of the panel. A keyed recess in communication with the plate aperture is adapted to interlock with a cooperative surface on the gauge stem at a predetermined location longitudinally spaced behind the gauge. A foot of a leg extending integrally from the plate at one end thereof toward the backside surface of the panel cooperates with a similarly extending preassembled thumb screw extending transversely through the plate at the opposite end to effect mounting. The thumb screw also serves to adjustably draw and secure the gauge into its mounted position.

Abstract: A valve, such as a butterfly valve having an offset closure vane and stub shafts for operating the vane in the flow passage of the body, has all exposed and/or potentially vulnerable metal surfaces encapsulated in a corrosion-resistant polymeric plastic coating. Providing bearing support for the vane drive shaft are a pair of spaced apart journal bearings located in the shaft bore in a shrink fit relation to the coating thereat.

Abstract: Pipe joint components such as a metallic sleeve and companion nut of a compression-type pipe coupling are externally coated with a corrosion-resistant polymeric plastic. In a preferred embodiment the coating on the female of the components extends as a flexible skirt beyond the mating end face thereof to include an internally integral annular O-ring formation. The coating on the male fitting terminates behind the threads thereof in an annular ramp or boss adapted in assembly to be engaged by the O-ring coating formation of the female fitting. Cooperation of the engaging O-ring and ramp effects a moisture seal relation thereat.