A system of compact and powerful high-pressure (700 bar) Enerpac RR series hydraulic cylinders, operating upside down, has been used to position large condensate storage tanks for Eni Australia on the Northern Territory coast.
The system, incorporating 10 of the rugged RR 1006 cylinders, was employed on 180 ton tanks manufactured in Perth, then barged up the coast and finally trucked to the remote area where they will hold liquid condensate piped from the Blacktip gas field in the Joseph Bonaparte Gulf. Erection of the condensate tanks is being undertaken by Monadelphous, a national engineering group.
The Enerpac hydraulic cylinders (357mm high with a 168mm stroke) were supplied to Monadelphous by Winnellie Hydraulics, Darwin, who developed and tested the positioning system prior to delivery.
Winnellie Hydraulics had to design the cylinders to allow a controlled descent of the storage tanks into position. The system had to be safe, reliable and serviceable, because of the remote area in which it was deployed. This presented a challenge because the heavy storage tanks measured about 18m in diameter and 18m in height.
After being manufactured in Perth and barged up the coast, the tanks were offloaded at a purpose-built wharf onto multi-wheeled low loader transporters that drove onto the barges. The transporters slid their trailers beneath the tanks, jacked up the trailers and hauled the tanks on a two kilometre journey from the wharf to the storage site. On arrival, the trailers lowered the condensate tanks onto blocks before driving away. The weight of the tanks was then taken up by Enerpac hydraulic cylinders supported on another set of blocks.
Ten 100-ton Enerpac RR-1006 double-acting hydraulic cylinders were used through AM41 and AM21 valving to safely lower each large tank into its final position. The cylinders were powered by a ZE5420SW 415 V electric pump with a 20 litre reservoir and a remote control.
An A-frame was manufactured by Monadelphous to house the AM41 and AM21 manifolds assembled as one unit with an inbuilt flow control valve and gauges for cylinder control.
The Enerpac cylinders were mounted upside down on the underside of the tank so that, as the blocks were progressively removed, the jacks did not have to be re-seated. Eventually the cylinders were lowered into a recess in the concrete that allowed them to be cut off the tank bottom and removed. Lowering and positioning the tanks was a gradual process that was spread over two working days.
According to Brian Wolter, Senior Project Engineer, Monadelphous Group, they found that the centre of gravity of the tank might not be in the middle, which meant that one cylinder module would be carrying more weight than another. They later had to adjust the positions of the modules around the tank circumference to best spread the load.
Enerpac’s RR-Series of double-acting cylinders have capacities ranging from 10 tons (101kN) to 520 tons (5108kN). They are suitable for tough job site use and are precision designed for high-cycle industrial uses. All cylinders have a built-in safety valve that prevents accidental over-pressurisation.
The 100 ton RR-1006 model used on the Wadeye site has a stroke of 168mm, a collapsed height of 357mm and a cylinder effective area of 133.3sqcm when pushing. For heavy lifting in remote locations, the RR-Series is powered by an Enerpac ZE-Series electric pump. These pumps are ruggedly designed and built to stand up to harsh industrial environments.
Enerpac hydraulic cylinders address the needs of major areas of industry, including mining and energy, infrastructure construction, commercial and industrial buildings, road and bridgework, manufacturing, pipelines, mobile machinery, mobile and stationary vehicles, craneage and fixed plant.