DETAILED DESCRIPTION OF COMPLETE HYDRAULIC JACKING UNIT AND ASSEMBLY OF LIFTING TRESTLES.A jacking unit as illustrated in the adjacent figure, consists of the following componentsTo Construct Steel Storage Tanks, Diesel, Petrol,Oil, etc
Upright, Height 3, 500 mm
Base plate with attachment for upright
Lifting lug (welded to shell plate)
Guide (welded to shell plate)
Shut-off cock coupling for high pressure hose
Stay lug (welded to base plate).
The number of jacks required is determined by the size and weight of the tank
PRINCIPLE OF ASSEMBLY OF HYDRAULIC TANK JACKING EQUIPMENT
The foundation is made ready
The base is laid out and welded
The periphery of the tank is marked out on the base plate
Guide trestle for the shell plate are erected
The top shell plates are erected and welded vertically.
The roof trusses are assembled and joined to top shell
Lifting trestles with hydraulic jacks are fitted internally along with the periphery of the tank
Lifting lugs and guides are welded to the shell plate.
The top shell plate and the roof construction are lifted one plate height.
The roof plate is fitted and welded in place. At the same time, the next shell plate is fitted and welded
The lifting lugs and guides are removed from the top shell plate and new lugs and guides are welded to the nest shell plate. The hydraulic jacks are lowered to the original lifting position
The tank is lifted again to allow the continued erection of shell plate until the full height of tank has been reached.
When the last shell plate is fitted and welded in place, the finished tank is lifted slightly so that the guide trestles can be dismantled.
The tank is lowered and the shell plate and base plate are welded together.
The jacking equipment is dismantled.
Welding done at ground level.
Easy access for inspecting quality of welding
Roof is fixed to the top shell plate from the commencement rendering it stable against WIND-LOAD throughout the erection work.
Guide trestles stabilize the tank at the bottom maintaining its circularity and accuracy
Need of scaffolding is eliminated
Highest - Safety achieved as working is carried out at ground level.
Economy - Cost effectiveness achieved as labour and time required is minimized