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Bolt load accuracy should be a safety essential

Bolt load is one of many variables in joint integrity management across industries and calculations must be “just right”.

Science and astronomy are areas where this Goldilocks theory term is commonly used. It was adopted from the children’s story and even describes Earth, which has the exact conditions to support life.

Tools, personnel and equipment should be considered carefully when applying bolt load. The objective remains the same whether the bolted connection is topside, subsea, on a nuclear asset or part of a wind turbine – to ensure the joint is secure and safe from start up. This gives it the best chance of a long, successful service-life.

Calculations must be made based on knowledge of the component elements of the specific joint and on the fact that when joints are tightened their behavior can be influenced by operational and/or environmental conditions.

At Hydratight, we know extremes are dangerous when it comes to bolt loading. There’s no room for over-tightening and under-tightening can be just as harmful.

On an oil and gas pipeline or service line, bolt load that is too high could result in the gasket plastically deforming, extruding or being destroyed, causing a leak.

If too low, the gasket could be insufficiently energized, allowing contained gases or liquids to be released. In high pressure or hazardous substance situations the effects can be life threatening and potentially environmentally damaging.

In the wind industry, bolted joints can suffer from criticalities if not tightened correctly during commissioning or during re-tightening activities. Regular service-life factors, including weather, vibration or corrosion, can be worsened if joints are not loaded correctly.

In any industry, excessive load (i.e. significantly more than required) typically results in damage and/or failure. Having the knowledge and experience to understand what is ‘just right’ is important.

Safety of people, integrity of assets and the protection of the environment are always front of mind for operators. They rely on best advice, well thought out joint integrity management plans, employing demonstrated procedures using competent personnel and quality equipment that will prevent any delays in production, unplanned shutdown or process safety incidents.

Hydratight has taken the lead in developing solutions to provide more certainty in decision making and greater predictability in the outcome. Hardware, such as hydraulic bolt tensioners can be combined with bolt load monitoring technologies to achieve accurate results, ensuring safe, controlled methods of applying bolt load.

The combination of proven procedures, quality and calibrated tools with competent people with demonstrated experience and should mean that everything is recorded and traceable.

In constantly changing working environments, it is essential to take up-to-date advice that must be based on combinations of reliable data and experienced human judgment. Bolt load should never be at extremes, but rather the optimum for each individual application. 

Hydratight can assure that it will always be ‘just right’.