Stage lifters safely move massive weights

Hydraulic stage lifting from Enerpac Integrated Solutions can provide a safe and cost-efficient technology by which large structures such as tanks, ship sections and buildings can be safely lifted over virtually unlimited stroke heights.

Stage Lift systems, in capacities typically from 10 - 400 tonnes per lift point, overcome limitations imposed by hydraulic cylinder strokes that are too short for some jobs. The systems can enhance safety and save time and money by removing the need to constantly reposition multiple cylinders, says Richard Verhoeff, who is Integrated Solutions Manager for Enerpac In Australasia.  

Compact but powerful 700 bar Stage Lift systems - operating in multiple steps - can be actuated remotely, manually or synchronised with PLC controls, within tolerances of less than 1 mm, to lift, hold and lower large objects in applications such as:

• tank jacking and lowering, including maintenance of storage tanks;
• lifting buildings, structures, infrastructure and platforms;
• precise lifting of turbines, transformers and fuel rods;
• maintenance of heavy plant and equipment;
• ship segment lifts and heavy cargo positioning;
• lifting of bridges and bridge elements; and
• lifting conveyor belts in the mining industry.

Instead of operating like standard cylinders that project their plunger upwards under a load, stage lifting cylinders project their plunger downwards when lifting. This downward force lifts the cylinder body, its spreading plate and its load clear of the ground so cribbing blocks can be placed under the spreading plate that is integrated into the cylinder. When the load is supported by cribbing blocks, the plunger is retracted so further blocks can be placed under it and it can press down again to lift the load a stage further. The process can be repeated multiple times, says Verhoeff.

Capable also of operating horizontally, Stage Lift Systems are employed to move large weights where other methods such as cranes are impractical, cannot gain access to lift, or do not offer the controlled precision of hydraulics.

“A beauty of the Stage Lift System is that it can be employed as several or multiple units controlled by traditional valving and safety systems - or it can be operated via Enerpac’s PLC-controlled Synchronous Lifting System, with which one person can control huge lifts from a safe distance,” says Verhoeff.

Stage lifting types include:

• BLS/BALS stage lift cylinders in steel or aluminium with capacities from 25 - 250 tonnes, featuring cylinder in climbing plate, rotation protection of plunger, tilt saddle on cylinder base; and
• Jack n Pack heavy lifting types in capacities from 50 - 400 tonnes, in steel housings.

The EVO synchronous system has eight standard hydraulic control modes and can control 4, 8 or 12 points with one hydraulic power unit (HPU). A master control unit is also available that offers daisy chain control of up to 16 EVO systems, giving a maximum of 192 lifting points.

Safety benefits of the PLC-controlled system include elimination of the potential for error with the multi-operator manual control approach. The digitally precise EVO-system incorporates warnings and stop functions. It offers full monitoring and control, with programmable fail-safe monitoring and safety alarms.