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Hot work, no shutdown

17th April 2013

Hot work on offshore installations and petrochemical plants is a serious matter and will often result in "shutdown time", but with the right equipment the "shutdown time" can be eradicated or kept to a minimum

Hot work, no shutdown
Hot work consistently ranks among the top five leading causes of fire across all industries

Hot work is one of the riskiest activities an oil and gas operator can undertake on their facility and continues to be a leading cause of industrial fires,consistently ranking among the top five across all industries and responsible for many of the industry's most severe fire losses. The process is often synonymous with welding and cutting but also includes any work activity with potential to produce ignition sources or excess heat, such as burning, brazing or grinding.

 

Sparks and molten material from hot work can be scattered more than 35ft during welding, cutting and grinding. These sparks and slag are typically at a temperature above 538°C when thrown from the hot work operations — a temperature which can easily ignite paper, wood, flammable liquids, vapours and any other combustibles they are allowed to come into contact with.

 

While designated hot work areas should have a 35-ft clear radius of combustibles typically maintained, there are very few areas in the average facility that are always clear of combustible material 35ft in all directions from a given point. If combustibles are not relocated or protected, the hot sparks and slag from welding can easily lead to ignition. Nonetheless, many operators still consider the use of leather hides placed around a hot work job in a hazardous area a secure and adequate method by which to contain and manage the associated risk of an ignition source.

 

Hot work procedures such as welding, burning and grinding on oil and gas production platforms have conventionally meant shutting down production to ensure volatile gases which can leak into the atmosphere are not ignited. However, in many instances shutting down the operation is either not immediately feasible or can actually increase the risk due to a hydrocarbon processing plant being at its most vulnerable during shutdown and start up. Furthermore many operators do not welcome the loss of revenue. However, it looks as if China’s oil and gas/petrochemical industry has found a safe and effective solution to avoid or at least minimise the impact of this costly and undesirable operational constraint.

 

Thanks to the recent introduction of pressurised welding enclosures, more commonly known as habitats, to the Chinese market, decision makers now have another option for how they can safely undertake their hot work processes in a live plant. Unscheduled shutdowns required for performing hot work can now be responded to and undertaken rapidly and safely in a controlled and planned environment or in many cases entirely circumvented. Habitats are beginning to change the way in which offshore installation managers (OIMs), project managers and health, safety and environment (HSE) managers approach and deal with hot work maintenance in China’s oil and gas industry. Where before complex projects may have required significant shutdowns in order to safely allow large amounts of hot work to be carried out, habitats now enable the facility to remain operational throughout the hot work process, helping to protect the company’s workforce and assets.

 

Safe, enclosed and pressurised habitats are being used in the execution of hot work within refineries, gas plants, petro-chemical plants and offshore platforms as well as floating production, storage and offloading (FPSO) units. Internationally accredited and ATEX approved, habitats are currently being deployed by ROC Oil and ConocoPhillips in Bohai Bay, Worley Parsons in Hong Kong and CNOOC in Indonesia each time they carry out hot work procedures in zones 1 and 2.

 

So how does the habitat work?

Since the habitats are sealed and pressurised they deny the ingress of hydrocarbons, thus allowing hot work operations to be safely executed, even when the surrounding process plant is fully operational. This is an interchangeable system of flame retardant textile panels and the habitats can easily be deployed to the point of delivery, allowing prompt installation in any location regardless of the accessibility or complexity of the worksite. The habitats are designed to be simple, safe and quick to install. The use of lightweight materials allows one skilled technician to safely construct a habitat in only a few hours. No hand tools are required to install the habitats and by using zippers and Velcro seals it virtually eliminates the risk of hand/arm injury.

 

Typical applications include repair and maintenance of critical equipment, piping tie-ins and structural modifications during pre and post shutdown, on-the-run maintenance and Brownfield construction projects. The principal components are modular panels fabricated from high specification flame retardant and fire proof fabric. The panels are zipped together to create the required size and shape of the habitat. Another advantage of the enclosures is that despite their numerous benefits and high technology they are not cost-prohibitive. These new enclosures are reusable and also recyclable, so there’s a benefit to the environment.

 

This article was written by Ian Ross, general manager, Safehouse Habitats.

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