The jacking system requires various scaffolding and attachments to provide comfortable access for welding heights, but now all weldings can be done at ground level.
Welding inspectors can now perform ultrasonic or other non destructive tests on welds at ground level, which facilitates ease of inspection for better quality control. No more climbing up to perilous positions for welding inspectors.
The shell plates are erected at ground level instead of being installed at the height of about 30 feet or more, saving construction time required for alignment of plates. The time and manpower required for lifting the plates to the height is eliminated. Construction work remains unaffected by rain or snow, since most work is done under the protection of the tank itself.
New shell plates are constructed at ground level instead of being hauled up to about 30 feet heights or more, saving considerable time required for alignment of plates. The cumulative time required for lifting of men and material to heights is eliminated. Tank construction work remains practically unaffected by rain or snow, since most work is performed under the protection of the tank itself.
Example : Tank of 30 m diameter weighing about 300 tons needs 30 jacks of 12 ton each. Full cost of jacking equipment can be recovered in 4 such tanks.Model Description 510-35D 2510-50DWorking Capacity (metric tons) 12 25Testing load (metric tons) 18 37.5Standard arc distance between jacks (m) 1.80 to 3.0 Max plate height for which jacking equipment can be supplied (m) 2.5 or 3.0 or moreMin plate height that can be used (m) 1.40Min safe bearing capacity below trestle base plate (N/mm2) 1.45Plate thickness range (mm) 6 - 40 8 and above Unitary climb (cm/stroke) 10Time per stroke (minutes) Approx 5Working pressure (kg/cm2) 120 135 Retracting system spring hydraulic