Abstract: A gas insulated electromagnetic induction appliance in which a non-condensing insulating gas and a condensing insulating coolant are confined, comprises (a) a pressure detector for detecting a pressure within the container vessel; (b) a gas reservoir connected to the container vessel through a gas discharging passageway including a pipe line, a first gas valve, a compressor, and a gas diffuser; a gas feeding passageway including a pipe line and a second gas valve; and a liquid feeding passageway including a pipe line and a liquid valve; (c) a definite quantity of insulating coolant confined in the gas reservoir; (d) a liquid surface detector for detecting a quantity of the insulating coolant in the gas reservoir; and (e) control means which controls the gas valve, the liquid valve, and the compressor to thereby regulate a pressure in the container vessel and a quantity of the liquid in the gas reservoir.

Abstract: A fiber optic bulkhead penetrator for allowing fiber optic communication lines to penetrate through an undersea bulkhead employed in offshore oil well exploration and production apparatus having a very high pressure differential thereacross. The arrangement consists of a port and cofferdam installed in the undersea oil well exploration and production apparatus, and a bullnose penetrator, having a plurality of bulkheads therein, terminating an undersea fiber optic cable used for data transmission. The bullnose penetrator serves as a mating plug for a port provided in the oil well apparatus, with three sets of seals isolating the single-atmosphere environment from the ambient seawater pressure. A shoulder is provided on the penetrator and in the port to hold the penetrator in place once the cofferdam is evacuated and lowered to habitat pressure.

Abstract: A liquid leak detecting sensor in the form of a coaxial cable assembly is provided in which means are provided for enhancing the passage of leaks from the outer surface of the outer conductor into the sensing layer which separates the inner and outer conductors. The change in permittivity of the sensing layer caused by the leak enables rapid detection of the location of the leak along the cable.

Abstract: Pipe coating having a thermal insulating layer of polymeric material and an outer barrier layer is provided with an additional layer between the two layers to facilitate testing of the latter for discontinuities. The intermediate layer can be electroconductive, smooth-surfaced, or of color contrasting to that of the barrier layer.

Abstract: Method and apparatus for replacing flammable, insulating oil in an oil-filled electric cable by non-flammable, insulating oil in which the flammable oil is withdrawn at least from the cable oil duct under vacuum and with heating of the cable to its maximum operating temperature and thereafter, the flammable oil which was withdrawn is replaced by non-flammable oil. During operation of the cable, oil which flows out of the cable during heating of the cable is sent to a first reservoir, through a check valve and during subsequent cooling, such oil is replaced by non-flammable oil from a second reservoir containing non-flammable oil and connected to the cable duct by a check valve. Also, an oil-filled cable having its insulation impregnated with flammable, insulating oil or a mixture of such oil with non-flammable, insulating oil and having an oil duct filled with a non-flammable, insulating oil which is different from the flammable oil.

Abstract: A liquid leak detecting sensor in cable form is provided wherein an element of the cable is a material which is easily deformable and which, on deformation, maintains the cable in the deformed configuration.

Abstract: A system for detecting the source of a faulty pressure reading in a telephone cable pressure monitoring system is provided. The system interrupts a phone line circuit midstream and provides a test system thereat capable of remotely and concurrently testing both sides of the phone line including a pressure responsive variable resistance at one end and a sensing system at the other end of the line.

Abstract: An enclosure includes a closed housing having a wall dividing the housing into a first compartment containing a high voltage portion of the power supply and a second compartment containing a low voltage portion of the power supply. A dielectric fluid fills the first compartment and partially fills the second compartment. A first check valve disposed in the wall enables fluid to flow from the first compartment to the second compartment during a temperature increase to compensate for expansion of the fluid in the first compartment. A second check valve disposed in the wall, in communication with the fluid in the second compartment, enables the fluid to flow from the second compartment to the first compartment during a temperature decrease to maintain the first compartment full of the fluid.

Abstract: Molecular sieve material is placed in the main condensate return in vaporization-cooled transformers. The sieve material can be removed and replenished without de-energizing the transformer.

Abstract: An electrical cable especially useful in oil wells having a gas conducting channel beneath the outer sheath and a valved vent through the sheath to prevent explosive decompression. Gases entrained in the cable's insulation can exit from the insulation into the channel, move longitudinally of the cable along the channel and exit from the sheath via the vent. The cable comprises an insulated conductor, a low gas-permeable sheath surrounding the insulation, the gas conducting channel located between the insulation and the sheath, and the vent in the sheath and communicating with the channel. The channel can be formed of a plurality of filaments or fibers located closely adjacent one another to form a bundle. A plurality of bundles can be used, which can extend linearly or spirally along the insulation or in interwoven form.

Abstract: A method of forming and testing a fluid tight seal comprises placing a sealing ring between two members between which the seal is to be formed, either the sealing ring or the respective members being so shaped and arranged that lines of contact are formed between the sealing ring and the respective members between which there are continuous grooves or channels between the sealing ring and the respective member. By establishing a pressure difference between the continuous channels and the ambient atmosphere, the integrity of the seal can be tested by monitoring any fluid flow to or from the closed groove or channel. A single source of fluid pressure may be coupled to both grooves or channels via a union in one of the members and one or more transverse bores in the sealing ring.

Abstract: Pipe coating having a thermal insulating layer of polymeric material and an outer barrier layer is provided with an additional electro-conductive layer intermediate between the two layers to facilitate testing of the latter for discontinuities by conventional electric testing equipment for detecting discontinuities in the outer barrier layer, e.g. by measuring electrical conductivity or resistivity along the face of the barrier layer.

Abstract: The invention is the use of a solid conductive polymeric composition, which displays a massive resistance increase upon exposure to an external fault condition, as one plate of a capacitor for a continuous sense and locate device. This resistance increase of the conductive polymeric composition (CPC) decreases the capacitance of the capacitor so as to provide an indication of the fault and its location.

Abstract: A resistivity sensor system for use with sealed, gas-insulated electrical apparatus. The system includes a resistivity sensor for placement within a housing of the electrical apparatus. The sensor itself includes an electrically insulating substrate, a pair of spaced-apart electrodes located on the substrate, and a polymer film in the space between the electrodes. The electrical resistivity across the polymer film changing significantly with the occurrence of a fault within the vicinity of the sensor, as the fault causes a reaction at the polymer film. To detect the location of the fault, a voltage is applied across the electrodes, and the current flowing through the electrodes is measured.

Abstract: A cable assembly for detecting the ingress of water inside a cable is disclosed. The cable assembly comprises a moisture detecting tape constructed of two parallel bare conductors laminated to an insulating substrate. The tape thus constructed is applied in an open helix around the conductor core of a cable. A suitable plastic jacket is extruded over the cable core and the moisture detecting tape. A shielding tape may also be applied over the cable core and the moisture detecting tape prior to extrusion of the overall plastic jacket. The cable thus constructed with the integral moisture detecting tape is adapted for connection to a suitable sensing apparatus at one end, and should moisture enter the cable as a result of damage to same, the electrical characteristics of the detecting tape would change and such change will result in a measurable conductance between the conductors of the moisture detecting tape. The ingressing water is thus sensed prior to penetrating and compromising the cable core.

Abstract: A method and apparatus for controlling the pressure of gas sealed in a coaxial communication cable so as to maintain the dielectric constant and hence electrical length thereof constant independent of temperature or the leakage of insulating gas sealed therein. Electrical signals are produced representing the temperatures of the gas sealed in the cable and the temperature of a reference gas sealed in a closed container as well as signals representing the pressures thereof. The two temperature signals are compared and the temperature of the reference gas adjusted in accordance therewith by a constant temperature bath. The two pressure signals are compared and gas is fed into the cable in accordance therewith. The temperatures of the cable and the reference gas are maintained at the same values as are the pressures thereby maintaining the density and hence dielectric constant of the gas sealed in the coaxial cable constant at all times.

Abstract: A vaporization cooled transformer utilizes the vaporized coolant at a constant predetermined pressure for upgrading the dielectric strength of the coolant. An auxiliary heater is employed for vaporizing the coolant at low temperature ambient conditions. The constant predetermined pressure is maintained at higher ambient conditions by controlling the cooling capacity of a plurality of heat exchangers.

Abstract: A partition insulator is disclosed having a seating in at least one insulator holder. A specific predetermined rupture behavior is provided for the partition insulator as a result of outside forces acting on the insulator at a specific quantity and direction such as, for example, gas pressure. A corresponding support (or gripping or solid gripping) of the partition insulator is provided whereby at least on the insulator, on the insulator holder or between these two parts, bearing points (or bearings) are arranged in a suitably distributed manner. The gripping of the partition insulator is accomplished herewith by the insulator holder alone or by both the insulator holder and a fastening ring which holds the partition insulator together by both threaded bolts and nuts. The partition insulator is preferably used as a pressure relief device in pressurized gas-insulated high-voltage switchgears having a metal switchgear casing.

Abstract: An electrical penetration apparatus is described for mounting within a containment wall of a nuclear reactor installation to pass electrical currents while avoiding the outward leakage of radioactive gasses, which can be constructed at relatively low cost. The apparatus includes a pair of cup-shaped casings that face away from one another and have slightly separated base walls, a group of rod-shaped conductors extending through aligned holes in the base walls of the casings and through the separation space between them, and a quantity of potting material disposed in each of the casings and sealed to the conductors and to the inside surfaces of the casings.

Abstract: A high voltage transmission line suspension insulator (18 or 22) which monitors its own dielectric integrity. A dielectric rod (10) has one larger diameter end fitting attachable to a transmission line and another larger diameter end fitting attachable to a support tower. The rod is enclosed in a dielectric tube (14) which is hermetically sealed to the rod's end fittings such that a liquidtight space (20) is formed between the rod and the tube. A pressurized dielectric liquid is placed within that space. A discoloring dye placed within this space is used to detect the loss of the pressurized liquid.

Abstract: A district heating line comprising an inner metal tube intended for the transfer of a heating medium and encircled by an insulating layer of foamed plastic. Arranged around the insulating layer is a moisture impenetrable protective tube. To enable an alarm to be given in the event of a fault in the line, elongated blocks are fixedly mounted on the outer cylindrical surface of the metal tube. The blocks are made of electrically insulating material. They each have at least one radially extending, outwardly opening channel on the outer surface thereof with the channels on adjacent blocks aligned with one another. The channels are dimensioned to accommodate the electrical conductor and position it at a fixed distance from the outer cylindrical surface of the inner metal tube. The conductor is secured in the aligned channels at the fixed distance from the outer cylindrical surface of the inner metal tube. A water soluble salt is incorporated in the electrically insulating blocks.

Abstract: A district-heating line comprising an inner metal tube intended for the transfer of heating medium and encircled by an insulating layer of foamed plastic. Arranged around the insulating layer is a protective tube. To enable an alarm to be given in the event of a fault in the line, there is fixedly mounted on the outer cylindrical surface of the metal tube, an elongated block which carries at least one alarm conductor, said conductor being grouted in a fixed position in an associated channel in the block by the foamed plastic insulating material. In this way, the alarm conductor can be fixed at a given distance from the metal tube, to facilitate the localizing of a fault.

Abstract: A tension leg cable is connected between a floating structure and a seafloor anchor means. The cable is a multi-strand cable having voids between adjacent strands. A fluid tight vulcanized rubber sheath is provided covering an outer surface of the cable. A fluid tight corrosion resistant tubular member surrounds said sheath so as to define an annular space between the tubular member and the sheath. Means is provided for supplying an inert gas under pressure to said voids and said annular space. Means is provided for monitoring the pressure of said inert gas in said voids and said annular space to detect changes in said pressure so as to indicate a leak in either said sheath or said tubular member. Methods of construction of said tension leg cable are also disclosed.

Abstract: In a gas-insulated electric apparatus, such as a gas-insulated switchgear and a gas-insulated bus, having an insulating-gas-filled metallic container or sheath within which an electric conductor carrying a high-voltage current is supported by an insulating supporter, a potential detected by a first potential detector through at least a portion of the insulating supporter and another potential detected as a reference value by a second potential detector through an electro-static capacity disposed between the metallic container and the second potential detector are fed to the inputs of a differential amplifier of a partial discharge detecting device to thereby detect possible partial discharges along the insulating supporter with high sensitivity.

Abstract: Electrical apparatus includes an outer enclosure, an electrode within the enclosure, and an insulating gas electrically insulating the electrode from the enclosure. A support plate is secured to the outer enclosure, and the support plate has an opening therein. A housing, containing valve means, is secured to the support plate adjacent the support plate opening. An end plate is secured to the end of the housing. The valve means in the housing are capable of being in two positions, a first position preventing the flow of gas past said valve means, and a second position wherein an opening which is through the valve means is aligned with the support plate opening.An opening is formed through the enclosure in the wall portion thereof which is in alignment with the support plate opening. The opening through the enclosure is formed without generating contamination particles within the enclosure and in a manner which minimizes escape of gas from the enclosure.

Abstract: A modular lightweight, high voltage guyline insulator for VLF antennas. A glass fiber or "Kevlar" rod tension member that provides high tensile strength is enclosed by a porcelain jacket, which serves as a good high voltage insulator, preventing an arc breakdown along the surface and protecting the tension member from exposure to ultraviolet radiation which could cause the tension member to deteriorate. A rubber sleeve extends between each end of the porcelain jacket and a guyline fastening means, and together with the porcelain jacket forms a cavity or chamber around the tension member which is filled with SF.sub.6 gas, pressurized to 2 to 4 atmospheres (29.4 psia to 58.8 psia). Metal strips and metal toroid corona rings act to diffuse the electric field.

Abstract: An electric penetration assembly for passing electrical conductors through the wall of a pressure vessel has at least one hermetically sealed electric feed-through conductor surrounded by an insulator. The insulator is symmetrical about an axis parallel with the conductors and is impervious with a pervious means disposed between the ends. The insulator is shaped wherein an external conical section is disposed between two external cylindrical sections and wherein the pervious means communicates with the conical section. The assembly is inserted into a header plate having at least one transverse aperture formed with a female conical section disposed between two female cylindrical sections. In the female conical sections are formed two axially spaced grooves for accepting O-ring type gaskets and the plate has at least one capillary bore formed therein which communicates with the conical section and with one face of the plate.

Abstract: Overpressure protection for a vaporization cooled electrical inductive apparatus. A pressure responsive device is actuated by a predetermined pressure within a sealed housing and de-energizes a pump, thereby stopping the flow of dielectric fluid to the heat producing members which prevents further pressure increases within a tank due to continued vaporization of the dielectric fluid. In one embodiment, a discharge valve is actuated by the pressure responsive device to drain the dielectric fluid from the windings to prevent further pressure increases caused by continued vaporization of the dielectric fluid. A fusible link is provided to disconnect the windings of the electrical inductive apparatus from a source of electrical potential subsequent to the de-energization of the pump. In another embodiment, the pressure responsive device actuates the circuit breaker which disconnects the windings of the electrical inductive apparatus from the source of electrical potential.

Abstract: Apparatus is provided for pneumatically communicating with a pressurized cable provided with a peripheral opening. The apparatus includes a saddle of resilient material having a cross-section defined by a parabola and the arc of a circle. The saddle is adapted to sit astride the cable in surrounding relationship with the opening. A pneumatic fitting is molded into the saddle in generally parallel relationship with the cable. The saddle is provided with a bore communicating with the fitting and generally perpendicular thereto. The bore communicates with the opening in the cable. A sealing compound is provided between the saddle and the cable and the saddle is held on the cable by a pair of straps holding a metal strip against the saddle. An orientation protrusion is located on the saddle in alignment with the bore and protruding through an opening provided in the strip.

Abstract: An electrical penetration assembly is disclosed for providing a vapor and pressure seal between a conductor passing through two freestanding walls of a nuclear reactor containment which are subject to relative movement due to a seismic event. Penetration nozzles or tubes are placed through the walls of the containment when it is constructed. The penetration assembly is inserted into the nozzles and comprises a first subassembly fixed and sealed to a first penetration nozzle in the first wall and a second penetration subassembly in sliding or rolling engagement and sealed to a second penetration nozzle in the second wall. The sliding or rolling seal in the second nozzle allows the unrestrained reaction of the conductor to relative movement between the two freestanding walls during a seismic event without damage to the conductor or the penetration assembly. The penetration assembly also prevents the possibility of damage to either the conductor or the penetration assembly due to thermally induced stresses.

Abstract: A device for detecting electrical faults internal of a liquid and gas containing power transformer. Portions of two electrically nonconducting chambers are immersed in, and each chamber has an opening into, said liquid. One of said openings permits the relatively free passage of liquid through same and the other opening contains a liquid-immersed flow-restricting orifice. A sudden change in internal transformer pressure, indicative of an internal transformer fault, creates a pressure differential between chambers because of the liquid-immersed flow-restricting orifice associated with one of said chambers and the viscous properties of said liquid. This internal failure indicating pressure differential is sensed by a suitable differential pressure sensor which, in turn, actuates power transformer fault, indicating means.

Abstract: This invention relates to an arrangement for detecting the leakage fault of a pipeline by means of a sensing coaxial cable buried in parallel with the pipeline and divided into sections. When an oily substance such as petroleum leaks upon a portion of the sensing cable, the electric characteristics such as the impedance, or the distributed capacity of the cable will change. This change in the distributed capacity is used to detect a small variation in the cable caused by a small leakage of the oily substance, resulting in detecting the fault in the pipeline.

Abstract: A method and apparatus for forming pressure plugs in cable systems which are under continuous air pressure while maintaining a continuous air flow through the cable. A supplemental air source is connected to the pressurized cable casing on both sides of the area to be plugged to provide an auxiliary air pressure of sufficient quantity to override the normal pressure in the cable casing. Then, the pressure plug may be installed in the cable while the entire cable, and the selected portion of the cable being plugged, remain under adequate pressure to prevent any moisture from entering into the casing.

Abstract: In an apparatus comprising a high-voltage measuring capacitor and, in particular, comprising a high-voltage measuring capacitor formed by a high-voltage conductor of a fully insulated, metal-encapsulated high-voltage switch-gear installation and by a surface electrode associated with the former, an auxiliary capacitor is associated with and located adjacent to said high-voltage capacitor. The auxiliary capacitor is part of an evaluation device which generates a signal corresponding to capacitance changes of the auxiliary capacitor resulting from external influences. Following the evaluation device is an indicating device for signaling the occurrence of such capacitance changes and/or a control or regulating device for compensating for capacitance changes of the high-voltage measuring capacitor caused by the same external influences.

Abstract: An electrical penetration module formed of a unitary resinous material about the electrical conductor, with the resinous material compressively sealed to the conductor along its length. Mounting means are integrally formed in the exterior surface of the unitary body for sealably mounting the penetration module through the containment.

Abstract: A cable for detecting, in a stable and waterproof way, any leak of petroleum, petroleum product, or other fluid from an underground pipeline by means of a change in the electrostatic capacity between inner and outer conductors of the cable due to permeation by the leaking fluid. The cable offers constant, uninterrupted monitoring of such a pipeline with no limit to the watching range, and can accurately locate even a minor leak. The invention also involves a method of installing a detection system using such a detector cable, and a detection method which depends on electric pulses as means for detecting such a leak.

Abstract: A method of detecting the presence of moisture adjacent the exterior side of tubes in a pipe system such as a subterranean district heating system of insulated tubes, whereby it is measured or registered whether an electrical conductivity exists between two electric conductors permanently positioned immediately adjacent the tube in supposed dry and electrical insulating but hygroscopic surroundings. Furthermore, a pipe system and a pipe having means for facilitating the use of the said method, these means comprising one or more electrical conductors extending along each pipe embedded in the insulating material surrounding the pipe.

Abstract: A high voltage cable filled with an insulation gas under an operating pressure of more than 1 Bar, in which one or more conductors are supported by insulators, embedded in a tubular sheath of interconnected rigid elements and in which the gas-filled spaces of adjacent segments are connected together through a sealing element which is open under operating conditions and is closed when the pressures in the adjacent segments differ by more than a predetermined pressure difference.

Abstract: A transformer is provided that utilizes a substantially fully integral, generally outwardly convex casing or tank for enclosing an electrical transformer in a dielectric environment. The casing has fully integral side and top and bottom end walls, and has an open portion in its top end wall of sufficient size to serve both as a positive low to high pressure release and a maintenance hand hole. An easily inserted and removed cover assembly employs an operating stem, a domed cover member, a clamping member, a nut carrying bracket member and a spring that may be adjusted to a desired pressure relief setting by rotating the stem in one direction. Rotation of the stem in an opposite direction releases its clamping setting and loosens the parts of the cover assembly in such a manner as to permit it to be easily and quickly removed from the open portion by tilting it with respect to and out of the open portion.

Abstract: A hermetic electrical penetrator comprising a shell mounted in a single penetrator plate. A pair of axially spaced sealing members are sealed inside the shell defining a leak sensing chamber therebetween. One or more electrical contacts extend longitudinally through the sealing members in the shell. A sensing port in the wall of the shell communicates with the sensing chamber so that any leakage of gas through the shell can be detected by measuring the pressure differential between the inside and the outside of the shell. Preferably the sealing members are glass beads, and a porous ceramic spacer extends between the beads substantially filling the leak sensing chamber so that pressure differentials may be more easily detected.

Abstract: Liquid SF.sub.6 from the high pressure storage tanks within the gas sealed enclosure of a multi-interrupter gas insulated circuit breaker is collected in a tank located externally of the circuit breaker enclosure. A float within the liquid collecting tank operates a micro switch to effect operation of a solenoid actuated valve to pass the liquid SF.sub.6 into the low pressure system of the circuit breaker wherein it again returns to its gaseous state. The collected SF.sub.6 gas in the low pressure system is pumped back into the high pressure system through a compressor.

Abstract: A high-speed grounding apparatus for metal encapsulated high-voltage switching installations embodying a grounding bolt which, by igniting a propellent charge, can be forwardly shifted out of its rest position into its grounding or earthing position for electrically connecting the capsule with a conductor encapsulated therein. An ignition device is provided for the propellent charge, this ignition device being triggered by an increase in pressure in the switching installation.

Abstract: An improved seal structure for an electrical penetration in which at least one conductor is sealed within a tubular metal enclosure member by a compressive setting resinous potting material. A seal shroud extends from the interior surface of the metal enclosure member and acts as the seal surface against which the resin forms a compressive seal, as well as against the conductor member. An annular foraminous reinforcing member extends from the free end of the seal shroud to provide an increased strength seal.

Abstract: The invention concerns an arrangement for cooling an electric cable which comprises deep-cooled inner and outer conductors at high voltage and zero potential, respectively, and is provided with cable terminations, in which said inner and outer conductors are connected with respective inner and outer ordinary conductors. The invention consists of the provision that separate cooling loops with a common coolant supply unit are associated with the inner and outer ordinary conductors, and that likewise separate cooling loops with a common return and a further common coolant supply unit are associated with the inner and outer conductors. In this arrangement, the heat losses produced can be removed to the coolant supply units with relatively high efficiency.

Abstract: The invention concerns apparatus for cooling an electric cable which comprises superconducting inner and outer conductors, is subdivided into at least two cable sections and is provided with cable terminations in which these inner and outer conductors are connected with respective inner and outer ordinary conductors. According to the invention, a common coolant stream for the inner conductors and inner ordinary conductors as well as for the outer conductors and outer ordinary conductors is provided for each cable termination and the cable section associated with it, the coolant being fed-in at that end of the cable section which is not connected with the cable termination. With this simple arrangement, quantities of dissipation heat produced can be removed to refrigeration machinery with relatively high efficiency.

Abstract: A conservator system for transformers includes a conservator tank. The apparatus is filled with oil which is saturated with a non-combustible gas. The conservator tank is connected by conduits to the top and if suitable also to the bottom of the transformer tank, respectively. The top of the conservator tank is filled with free non-combustible gas. A bag of flexible material is arranged in the top of the conservator tank and the interior of this bag is connected to the atmosphere so that it separates the oil and the gas in the tank from the atmosphere.

Abstract: High voltage apparatus having a voltage carrying part such as a conductor enclosed by a housing with a gas, such as SF.sub.6 under pressure, used as insulation in the housing in which, in order to prevent burn-off of the housing and the voltage carrying part in the event of an accidental standing arc, the wall of the housing and, optionally, the voltage carrying part are provided, in the area most likely to be exposed to an accidental standing arc, with a reinforcement against burn-off which includes means to relieve compressed gas pressure and is designed so as to have a heat insulating effect for the wall of the housing.