The volume of bolting jobs on existing and emerging pipeline projects has lead to a radical rethink about the way private and government groups approach fastening and maintenance tasks.

Whatever the job, safety has never been more of a priority. This charge has been led in large part by the major companies and government organisations, whose managers know the terrible personal and financial costs of bad safety practices.

Though 10 or 20 years ago flogging wrenches and sledgehammers were used on bolting jobs, today it is much more likely to find a technically savvy single person doing the work of several people, using a powerful hydraulic torque wrench or tensioner. This is possible due to the development of an array of professional bolting equipment, including advanced, ergonomic torque wrench technology from Enerpac.

Why hydraulic technology?

Portability and ergonomics are key when ensuring safety and efficiency on a bolting job, and a hydraulic torque wrench can be designed to be light and compact enough to fit into confined spaces easily. For example Enerpac’s high-pressure, 700 bar steel equipment offers outstanding power-to-weight ratios, whether in torque wrenches or the hydraulic nuts and hydraulic tensioners encompassed in its family of controlled tightening technologies.

Bolted joints must comply with specific safety demands, which can be very stringent, especially in pipeline flange and associated heavy fabrication tasks for heavy industry. There must be absolute certainty about the joint’s operational strength, and the power and precision of hydraulics provides certainty in the quality and consistency of the job.

Although manuals describe factors such as mounting, use, maintenance and operating conditions, designers and specifiers can never be completely certain that they have complied with the necessary standards in these areas. Many designers therefore opt for safety by using more or heavier bolts than necessary.

A better approach, however, is to employ the precision of a torque wrench combined with verified calculations to achieve the correct residual bolt load.

Which type of torque wrench equipment?

The choice of torque wrench type and ancillary equipment depends on the application, and there are many key aspects to consider. One of these is accuracy and speed of operation, as one is often useless without the other when embarking on highly repetitive tasks.

Repeatability is also crucial to ensure consistent torquing from one bolt to the next in applications ranging from fixed plant to mobile equipment – and especially equipment under pressure, such as tanks and pipelines. Where a large number of fasteners must have equal strength, tools such as the W low profile hexagonal wrenches and versatile S series square drive have terrific and precise repeatability across the entire range.

Tools should also be matched to the toughness and duration of the job. Steel comes into its own for rigorous, repetitive work, and the robust W and S Enerpac torque wrench types are designed for maximum durability in the long haul, day in, day out.

Also consider weight and effort, as even small increases in weight become larger and larger when you are doing the same job over and over again. Technologies such as the W low profile hexagonal wrenches for low clearance bolting applications weigh from only 1.4-5 kg, while the versatile S series of double-acting square drive wrenches extends from 2.7-31 kg.

And don’t forget the pump; compact and portable electric pumps are often the speediest and most efficient solution for jobs close to base where reliable power supplies are available. Prime among these are the ZU4T Series electric pumps; weighing between 32-36 kg, these cool running pumps are a radically new design with fewer moving parts to reduce weight and friction.

What if there’s no power?

Sometimes jobs don’t have easy access to pneumatic or electric power. Maintenance crews, for example, might have to drive or fly great distances. In these circumstances, it might be best to employ an alternative technology such as a torque multiplier. These manual tools can provide outputs as much as 70:1 times as great as the input.

Where a torque wrench is preferred and has to carry with it its own source of power, there are lightweight hand pumps available from Enerpac. The lightest of these is the P Series of aluminium-based pumps, weighing from 2.4-10 kg.

Can the tool get the job done?

Generally, the rule of thumb is that the torque wrench should have 50 per cent more capacity than required for a particular task. That leaves a capacity reserve that can be necessary for unscrewing bolted joints. For heavy applications, wrenches of twice the capacity are sometimes used.

Is there enough space?

As far as available working space is concerned, when height is sufficient, a square drive will be most satisfactory. But if height is limited, it will be better to choose a low model with cartridges. The Enerpac torque wrenches are extremely compact. Their ratchet system has fine toothing, enabling high precision and preventing drive jamming. The double-acting cylinders give precise torque at high operating speeds, while the compact high pressure design enables a high torque/weight ratio and offers more power reserve during operation. The revolving coupling can be turned 360 degrees at high pressure, meaning that the hoses can be in any position.

Enerpac’s latest wrenches are easy to handle and usable almost anywhere. Furthermore, the hexagon cartridges and adapters can be quickly replaced, without the need for extra tools.

Education, training and backup

Correct training and service backup is essential to get precision, efficiency and safety from tools used in remote, rugged and high safety environments. Enerpac’s 50 years as a global leader ensures an exceptional standard of technology, technical knowledge and practical support that can be delivered in the field throughout Australia and New Zealand.