Abstract: An axial flow depth filter having a cellulose filter medium of tissue paper spirally wound about a paperboard core is secured to a paperboard inner flow tube for operation by a full surface coating of high performance polyamide hot melt adhesive applied between the I.D. of the paperboard core and the O.D. of the inner flow tube along the entire axial length of the core.

Abstract: Insulating oil in electric power generation, transmission and distribution equipment such as circuit breakers, regulators, phase shifters, tank diverter switches and capacitor banks for respectively separated phases of a plural phase transmission or distribution line is filtered for removal of accumulated water, carbon particles and other contaminants by filters in oil circuits respective to each phase in the plurality. Each oil circuit respective to each circuit breaker includes a respective filter and circulation pump. However, all pumps in the plural phase power system, for example, are driven by the same motor and drive line whereby a fluid condition or circulation interruption of one oil circuit that requires termination of pump operation in the one oil circuit terminates the pump operation in all oil circuits. Pump motor power is preferably drawn from an energy source that may be independent of that served by the transmission and/or distribution power source.

Abstract: Insulating oil in electric power generation, transmission and distribution equipment such as circuit breakers, regulators, phase shifters, tank diverter switches and capacitor banks for respectively separated phases of a plural phase transmission or distribution line is filtered for removal of accumulated water, carbon particles and other contaminants by filters in oil circuits respective to each phase in the plurality. Each oil circuit respective to each circuit breaker includes a respective filter and circulation pump. However, all pumps in the plural phase power system, for example, are driven by the same motor and drive line whereby a fluid condition or circulation interruption of one oil circuit that requires termination of pump operation in the one oil circuit terminates the pump operation in all oil circuits. Pump motor power is preferably drawn from an energy source that may be independent of that served by the transmission and/or distribution power source.

Abstract: Insulating oil in electric power transmission devices such as a transformer is filtered for removal of accumulated water and carbon particles. The filter and circulation pump are usually located in a separate cabinet external to the transformer with circulation conduits connecting the filter, the pump and the transformer. To prevent environmental contamination by leaks or ruptures in the oil circulation conduits, secondary or sleeving conduits surround and protect the circulation conduits and additionally provide an independent leak flow conduit back to the filter cabinet dry sump. An accumulation of oil in the dry sump actuates a fluid sensor to transmit an alarm signal.

Abstract: Insulating oil in electric power transmission switchgear such as a load tap changer for a transformer is filtered for removal of accumulated water and carbon particles. The filter and associated circulation pump is usually located in a separate cabinet external to the switchgear with circulation conduits connecting the filter, the pump and the switchgear reservoir. To prevent or minimize equipment damage that is presaged by excessive insulating oil temperature, oil flow within the oil circulation conduits is monitored for temperature excesses. Alarms are issued and electrical loads are disconnected upon detection of an excess temperature event. If desired, provision may be made for disconnected the jeopardized equipment from its respective service load.

Abstract: Insulating oil in electric power transmission devices such as a transformer is filtered for removal of accumulated water and carbon particles. The filter and circulation pump are usually located in a separate cabinet external to the transformer with circulation conduits connecting the filter, the pump and the transformer. To prevent or minimize environmental contamination by leaks or ruptures in the oil circulation conduits, oil flow within the pump suction conduit is monitored independently of oil pressure within the pump discharge conduit. A flow rate or discharge pressure below a predetermined minimum operates motor control relays to terminate the pump drive motor operation and transmit appropriate alarms. Additionally, an accumulation of oil in the dry sump volume of a pump and filter housing also activates motor terminating relays and transmits an alarm.