There is described an electrical isolator comprising a first fluid-carrying member and a second fluid-carrying member spaced apart from said first fluid-carrying member, a resistive, semi-conductive or non-conductive component located between and sealed against said first and second fluid-carrying member, wherein said resistive, semi-conductive or non-conductive component is adapted to convey fluid flowing from said first fluid-carrying member to said second fluid-carrying member, a reinforcing composite encircling said first fluid-carrying member, said second fluid-carrying member and said resistive, semi-conductive or non-conductive component, wherein said reinforcing composite is continuous and provides a conductive path between said first fluid-carrying member and said second fluid-carrying member, wherein said reinforcing composite comprises fibre and a resin mixture, and said resin mixture comprises resin and a conductive additive.

The present invention provides a non-return valve for a resin injection system, especially for use in electrical cable joints, comprising: a valve housing which includes an outlet for a fluid flowing through the valve; and a valve body which is held by the valve housing and is freely movable between a closed position, in which the outlet is substantially sealed or closed to fluid flow by the valve body, and an open position, in which the outlet is substantially open to fluid flow. Thus, with the present invention, the valve body can be loosely held by the valve housing and the valve need not include any spring means to bias the valve body to the closed position. The invention also provides a resin injection system for sealing a localized breach in an object, such as an electrical cable joint.

A bushing includes an insulating housing, an electrical conductor, extending through the housing and an insulating fluid in the housing, wherein the insulating fluid has a viscosity at a temperature of 100 C. of equal or less than 2 mm.sup.2/s. The bushing includes a condenser body surrounding the electrical conductor, wherein the condenser body includes electrically insulating layers and electrically conductive layers, wherein the electrically insulating layers are formed from a paper impregnated with the insulating fluid.

A bushing includes an insulating housing, an electrical conductor, extending through the housing and an insulating fluid in the housing, wherein the insulating fluid has a viscosity at a temperature of 100 C. of equal or less than 2 mm.sup.2/s. The bushing includes a condenser body surrounding the electrical conductor, wherein the condenser body includes electrically insulating layers and electrically conductive layers, wherein the electrically insulating layers are formed from a paper impregnated with the insulating fluid.