Apparatus for checking for leaks from metal-clad high-tension electric gear

Apparatus for checking for leaks between the connection flanges of two portions of metal-clad electric gear, said flanges being sealed by means of two seals disposed concentrically in series on the facing surfaces of the flanges, said electric gear being filled with compressed gas, the improvement comprising a smooth bore hole in communication with the internal volume lying between the two seals and leading to the exterior of the metal-clad electric gear, and an axially compressible resilient cylindrical seal plugging said smooth hole as a result of increased diameter during axial compression for frictional lock therein, and wherein an insulator is inserted between said two flanges, said smooth hole is located in the periphery of the insulator and extends parallel to said two flanges and communicates between the outside and internal volumes between serially arranged sealing rings on both sides of the insulator through one hole projecting from said smooth hole to one side of the insulator and another hole projecting from said smooth hole to the other side of the insulator, and wherein said apparatus further comprises a pipe extending from the exterior into said smooth hole, said pipe bearing said axially compressible resilient seal in tubular form surrounding said pipe, and wherein a radial hole within said pipe communicates the interior of the pipe with one of said holes within said insulator leading to an internal volume between the serially arranged sealing means on one side of said insulator while said axially compressible cylindrical seal closes off the other hole within said insulator leading to the other side of said insulator.