Leak testing apparatus

A leak testing apparatus, for testing connections between a tube penetrating a plate material and the plate material, wherein the apparatus comprises:

• a housing having a central cylindrical longitudinal hollow, the housing having a first end, in use configured to engage the plate material surrounding the tube by abutting the plate material without longitudinally overlapping the plate material, and a second end opposite the first end, where a first seal is arranged projecting from the first end and where the second end of the housing is closed by an end cap;
• a piston arranged inside the housing, the piston having a longitudinal axis parallel to the longitudinal extent of the hollow, where a distal end of the piston in use is inserted into the tube;
• a second seal arranged circumferentially on the piston, such that in use the second seal may be brought into sealing engagement with the tube;
• wherein at least one channel is provided longitudinally in the piston and a connection to the channel allowing connection to a source of pressurized medium is provided, connecting the pressurized medium to a space, in use limited by the first seal, the plate material, the tube and the second seal, and optionally part of the piston and part of the housing;
• and
• wherein means are provided inside the housing for urging the piston away from the end cap, thereby bringing the second seal into sealing engagement with the tube.