Pyroban sparks some explosive questions

But how are explosions prevented and are companies doing enough to ensure that local practices truly reflect corporate safety values? NG Oil&Gas talks to safety specialists Pyroban®.

It was the early 70s when Pyroban saw their first enquiries roll in from the North Sea. The oil and gas industry was looking for solutions that would prevent a diesel engine being the source of an ignition if an explosive mix of hydrocarbons – for example hydrocarbon vapour released in the drilling process – engulfed the engine. Pyroban had solutions that quite simply broke the combustion triangle and prevented major industrial accidents at sea.

Today, risk is managed in much the same way as Rob Double, responsible for Pyroban’s business upstream explains “Standard fixed or mobile equipment, whether mechanically or electronically controlled, will have numerous sources of ignition such as hot surfaces or sparks, and any one of them could cause an explosion”

Upstream – managing equipment in hazardous areas

Pyroban’s core business for the upstream oil and gas industry revolves around the explosion protection of diesel engines and other associated equipment. Typical solutions provide safety for nitrogen vaporiser pumps, surface preparation equipment, cementing units, coiled tubing power packs, high pressure fluid pumps and air compressors.
Rob Double who is based at Pyroban’s global headquarters in the UK continues “Pyroban engineers look at every element of a piece of equipment, analysing the risks of ignition. Hot surfaces, sparks, ingestion of the gas into an engine causing overspeed and many other mechanical or electrical sources will be considered. The equipment is due to operate in areas that are classified as Zone 2* which means that flammable gases could be present in the atmosphere, so we have to make sure that any ignition sources don’t go near it.”

By applying a combination of explosion protection techniques such as cooling systems, gas detection or enclosures, Pyroban solutions remove any risk of ignition meeting local and international regulations such as ATEX 94/9/EC**, enabling equipment to operate safely without causing an explosion.

The asset owner is ultimately responsible for managing risk, and they must ensure that all operations are safe and comply with local regulations. In theory, if the risk is managed correctly at the top, responsibility is then passed right down the supply chain.

Pyroban’s strong links with the equipment manufacturers ensure that the user receives an explosion proof unit that provides optimum performance in some of the toughest environments and demanding duty cycles. These are all considerations when managing the risk and selecting equipment.

Double adds “Equipment goes nowhere without the right certification and documentation, and it certainly has to be supported. We make this part easy, providing a 24hr support hotline with offshore support engineers available to assist globally at short notice.“

Migration of upstream safety knowledge

“We have been seeing more activity in all oil regions throughout the world including South East Asia, the Middle East and parts of Africa. We have found that not only is safety knowledge migrating around the world, so is the very latest technology. It is unfortunate however that there still remains grey areas in knowledge and safety processes posing serious questions over the safety of many installations.” Adds Double

Pyroban recently provided a full zone 2 solution for a nitrogen unit intended for operation in the Middle East. The unit was on the dock waiting for despatch to a rig but the duty inspector refused entry on the grounds that it didn’t meet the correct specification, because the paperwork only required a shutdown valve and spark arrestor, 2 components that deal with only some of the ignition sources. The equipment supplier was forced to strip off the complete Pyroban explosion protection system leaving the oil and gas installation wide open to the risk of explosion.

Such varied safety knowledge and procedures led Pyroban to develop 3GP™ partly because procedures were being breached. Exhaust flame arrestors are usually an integral part of an explosion proof system but due to their weight, in many cases in excess of 45Kg, and because they have to be cleaned or changed every 8-10 hours, they were being replaced in operation by a ‘dummy’, exposing sources of ignition. 3GP meant that Pyroban could safely put equipment into operation without the exhaust flame arrestor by introducing an electronic control system and gas detection.

It is clear that standardisation and awareness regarding upstream safety still has a long way to travel across the world, but the risks also carry further downstream where the dangers even affect the general public.

Managing risk downstream

Heavily regulated by governments throughout the world, refineries and similar industries have a duty to ensure that any explosion risk is kept to a minimum. Within Europe and many parts of the world, refineries are required to comply with the requirements of the ATEX 1999/92/EC*** European Directive. However, the equivalent level of regulation and worker protection is not in place everywhere and on many refineries, workers remain at risk.

Pyroban provides area classification services and advises on operational practices to help minimise the risk of explosion whilst also providing full ATEX compliant solutions for all types of equipment. Malcolm Davis responsible for Pyroban’s business downstream explains “Of course companies must ensure that areas are classified where there are risks but the real concern is what is happening on a day to day basis in those areas as many responsible for site operations lack the experience, site discipline or budget to enforce safe and acceptable daily practice.”

Referring to European law, if an area is classified as Zone 1, then only equipment certified to Category 2G under the ATEX 94/9/EC equipment Directive should be used. For Zone 2 areas equipment certified to both 2G and 3G would be suitable because the equipment would be built safe and therefore not present any sources of ignition assuming it is maintained by trained engineers with an annual safety check.

Insisting on only Zoned equipment being allowed into the refinery is often neither practicable nor desirable. Pyroban provides thousands of fully explosion proof solutions every year for all types of equipment, but the company insists that black and white company policies are cause for concern.

“Imagine insisting that a 100 ton mobile crane required for a temporary maintenance job should be made fully explosion proof before being permitted on site. I doubt any hire company can afford to keep an explosion proof crane on standby for the occasional job. Or the personnel carriers, vans, tractors, tankers, mobile compressors and gen-sets operating inside the refinery perimeter not permitted into formally classified areas without first being made fully explosion proof.

In such applications the refinery relies on the use of hot work permits and risk management processes. The person(s) responsible for issuing the work permit should have the relevant experience and the necessary authority to manage the risk involved. But how do they limit the chances of the hazard and the ignition source coming together?”

Similar to the safety procedures upstream, it is also common to insist that for equipment powered by a diesel engine, an over-speed air shutdown valve and exhaust spark arrestor should be fitted. Provided these components are correctly fitted and correctly serviced (in the case of the over-speed valve typically every 3 months), they should alleviate only a couple of the many ignition sources found on a forklift truck, crane, tanker etc. Other ignition sources such as electro-static, flame flashback through the inlet system or flame emission (not sparks) from the engine exhaust and sparks from any electrical equipment such as alternators, lighting, instrumentation or engine management systems are all still left exposed. Even hot surfaces can cause auto-ignition.

Another common practice under the permit to work approach is for the operator to carry a handheld gas detector relying on the operator to “kill” the equipment before the equipment’s ignition source ignites the explosive atmosphere, but it is an undeniable fact that most accidents are caused by human failure.

“Relying on engine over-speed valves and handheld gas detectors may have been the traditional protection of yesterday, but with today’s diesel engines relying on electronics, this not the safest way forward considering the quantity of fixed and mobile equipment in use.”

The technology is available now for refinery operators to limit the risk to workers and at the same time allow the operator the flexibility needed to do the job through ensuring that:

• equipment has its own integral gas detection system which will only allow it to function when the immediate area is free of flammable gas or vapour
• before the operation begins, the equipment has an enforced automatic gas test to ensure it is calibrated correctly,
  
• the gas detection system automatically shuts down the equipment it is protecting well below explosive limits,
  
• if shutdown does occur, any restart is controlled by a person in authority and
  
• Installing protection systems that are simple to fit, use, maintain and most importantly designed to isolate the many ignition sources from an explosive atmosphere.

Malcolm Davis concludes “It is the safety culture that needs most attention and the necessary budgets for implementing safety are fundamental to change. With the right mindset, small changes to processes and procedures can significantly reduce the risk of an explosion and improve the overall safety of workers both upstream and downstream.”

About the company

Pyroban Group Ltd provides explosion proof safety and environmental solutions for industry worldwide. The company was founded in 1972 with manufacturing facilities in the UK, Holland, and China with regional sales and service centres.

Please make all PR and advertising enquiries to Molokini Marketing Ltd:
MOLOKINI MARKETING Ltd contact : Katie Davies T: +44 (0) 1903 704479
Podium House, 61 Chapel Road, Worthing, West Sussex, BN11 1HR, UK
Katie@molokini.co.uk | www.molokini.co.uk

PYROBAN GROUP Ltd contact: Zoran Milivojevic, T: +44 (0) 1273 466200
Zoran.milivojevic@pyroban.com | www.pyroban.com