Hydraulic Wrenches Add a New Twist to Maintenance


The Century mine in northwest Queensland, Australia, reports that it has experienced good results following a changeover to steel-bodied Enerpac hydraulic torque wrenches for maintaining its heavy vehicle fleet.

Alloy-bodied hydraulic wrenches weren’t up to the task of keeping a 45-strong fleet of Komatsu 830E 240-ton haul trucks maintained and operational.

“We have about four trucks in our maintenance workshop at any one time, undergoing major overhauls or having breakdowns repaired. We need strong and reliable tools,” said Workshop Engineer Wesley Lloyd. “There were ‘dramas’ with the previous wrenches, which didn’t stand up to the hydraulic pressure required. The tool bodies twisted and leaked oil. This ultimately could have become potentially dangerous so because of our safety-first priority, we decided to try something different. “We were already using Enerpac hydraulic cylinders at the mine, so we asked the company to demonstrate their torque wrenches. The results were good. The Enerpac tools can handle the required force,” said Lloyd.

Among the truck bolting applications performed by the hydraulic wrenches are dismantling and reassembling the front suspension struts, removing and replacing the vehicle nose cones, and servicing the pivot eyes between the rear wheels and the chassis. Bolt sizes vary.


Enerpac hydraulic wrenches are used to service heavyduty equipment
at the Zinifex Century zinc mine.
Century now has three of the W Series of low profile Enerpac hexagonal-drive torque wrenches, driven by Enerpac 3000 series air-powered pumps. The W series hexagonal wrenches for low clearance bolting applications weigh as little as 1.4 to 5 kg and provide precise, repeatable torque from 2,712 to 2,0337 Nm. They are complemented by Enerpac’s S series of doubleacting square-drive wrenches, which weigh from 2.7 to 31 kg with outputs of 1,898 to 3,4437 Nm.

“The hydraulic wrenches perform to expectations, with no flexing of the tool body. They sustain their shape, without oil leaks,” Lloyd said. “The wrenches are no more expensive than the other type we used and there’s also not much weight difference. We thought they would be heavier, being made from steel, but this is not the case, as they aren’t as large.

“The compact tool head means we have more access space in tight spots where it can be hard to get a positive grip on the bolt. This also speeds up the job, since we don’t have so much manipulation to do,” he said.

The W series torque wrenches don’t require tools for changing heads, and their pinless construction includes quickrelease cylinders and automatic crank engagement. On-site maintenance is possible without special tools. An in-line reaction foot on the hexagonal drives and unibody construction on the square drives reduces internal deflections for greater accuracy.

As featured in Womp 08 Vol 1 - www.womp-int.com