The introduction of Enerpac hydraulic bolting technology into the maintenance workshop of Queensland Bulk Handling (QBH) at the Port of Brisbane has made bolting tasks far less strenuous, safer and quicker as well.
Among the equipment serviced at the export coal terminal is a D10R Caterpillar Dozer used for pushing and stockpiling coal. The grouser plates on the track chain must be replaced as they wear out every 16,000 hours or so – a big job, says maintenance engineer Steve Blaik.
“To secure the plate bolts we had been using a 16.1 torque multiplier, about 500 mm long, employing arm power. This was hard work!” said Blaik.
“As well as being labour intensive, it was also very time consuming. One man could do it, but we used two for safety’s sake.”
The bulldozer is serviced for one day at a time whenever the maintenance team can get access to it. Of its total of 86 grouser plates, each secured with four bolts, about ten plates are replaced per maintenance session which means the release and resecuring of around 40 bolts.
“I wasn’t happy with the method we were using. We already had other Enerpac equipment in the workshop, so I asked the company for a demonstration of their hydraulic torque wrenches. They showed us and we were very impressed.”
The tool chosen by Queensland Bulk Handling is one of the versatile S series of double-acting square drive hydraulic torque wrenches.
They weigh from 2.7 kg to 31 kg, with outputs of 1898-34,437 Nm. The nose radius of the wrenches ranges from 25-63.5 mm, with the square drive ranging from three-quarters to two-and-a-half inches.
“Learning to use the torque wrench was simple. The instruction manual made it quite clear and easy to understand. We pre-set the tension we want and the wrench automatically tightens the bolt until that figure is reached,” Blaik said.
QBH’s hydraulic torque wrench is powered by an Enerpac ZU4 electric pump.
“Using a hydraulic wrench is definitely safer than the old method. And since there are a lot of bolts to be tightened, it’s easier on the guys as well. I didn’t think the previous system we used was satisfactory – and it was also taking us too long.
“We’ve been using the Enerpac torque wrench for a number of months now. It’s effective and trouble-free,” he said.
Features of the S series square drive torque wrenches include:
- 360 degree click-on, multi-position reaction arm and push-button square drive release for quickly reversing the drive for final tightening or loosening. A fine tooth ratchet prevents tool lock on
- Compact high-strength nickel plated uni-body construction for a small operating radius. The robust design with minimal parts facilitates easy on-site maintenance without special tools
- Lightweight ergonomic design for easy handling, with an optimised strength-to-weight ratio and fast operation because of the large nut rotation per wrench cycle (35 degree rotation angle) and rapid return stroke.
Enerpac also provides the W series of low profile hexagonal wrenches for low bolting clearance applications. These wrenches weigh just 1.4-5 kg, yet have precisely repeatable torque from 2712-20337 Nm.
In both the hexagonal and square drive wrenches, constant torque output provides high accuracy across the full stroke.
An in-line reaction foot ensures accuracy by reducing internal deflections in the hexagonal drives, while uni-body construction ensures accuracy in the square drives by reducing internal deflections.
The W and S series of hydraulic wrenches complemented by Enerpac’s advanced pumping technology and more than 50 years of application expertise are designed for maximum durability, reliability and safety, with rigid steel design and outstanding power to weight ratios.
The wrenches address the needs of major areas of industry, including mining and energy, infrastructure construction, manufacturing, pipelines, mobile machinery, tracked and heavy vehicles, craneage and fixed plant.