Jack Model 2510-xxD-x-H-x ("H" = Hook)
These jacks come with a “lifting hook” instead of the lifting arm. The hook holds and lifts the tank shell from the bottom edge of the plate. Welding of lifting lugs and fend-off lugs is eliminated and so is the need to test and repair tank shell plates after removing the lugs.
These jacks come with a “lifting hook” instead of the lifting arm. The hook holds and lifts the tank shell from the bottom edge of the plate. Welding of lifting lugs and fend-off lugs is eliminated and so is the need to test and repair tank shell plates after removing the lugs.
Jacking equipment with lifting hook is denoted by the “H” in the Model code.
Procedure for fixing next shell course and removal of hooks is explained below : The tank is lowered down using jacks, to sit on the newly erected shell ring leaving a root gap as required. To do this, the jacks are lowered down by about 70 mm, and strongbacks are fixed to connect the tank with the new shell ring. There is no vertical gap between the tank and the newly erected shell ring, since the plates of the new shell ring are pushed outwards locally at the hook locations. At this time, the load of the tank is released from the jacks, however the lifting hooks are merely stuck between the constructed part of the tank and the new shell ring. Now one by one, using a chain block or a pulling machine (tirfor), each hook is pulled out downwards, so as to free the lifting hook and allowing the hook to drop onto the jack.
