New technology developed by safety company Pyroban® has put a stop to the daily maintenance of ATEX diesel engines powering temporary well service, production and pumping equipment.

“With new technology, cleaning exhaust flame arrestors every eight hours is a thing of the past,” says Rob Double, Sales Director for Pyroban. “This applies to new equipment and almost all existing Pyroban protected engines already in the field, once they are fitted with a simple replacement part.”

Exhaust flame arrestors are a critical part of an explosion proof system found on engines used in Zone 2 hazardous areas offshore. They allow the engine exhaust gases to pass through and will stop a flame in the event of hydrocarbon gas ingestion, but in certain operating conditions they can clog up with soot very quickly.

Pyroban has developed two different solutions to eliminate the plate type exhaust flame arrestor from the explosion proof diesel engine design.

In April 2020, Pyroban launched Ever Clear™ Exhaust (ECE) Flame Arrestors which are a direct replacement for plate type flame arrestors. These are bolted into the exhaust system between the turbo and gas cooler, on the hot side of the exhaust flow. They are low in cost and can easily be retro fitted in the field to existing equipment. Pyroban has options for most turbo diesel engines above 100bhp.

As a more advanced alternative, Pyroban’s Ex SCS™ was launched in 2018 to combine flame arrestor elimination, safety shutdown and diesel engine control and monitoring in one flexible package. The system brings an active approach to the overall safety system by introducing gas detection into the engine inlet tract at a certified position and also within the equipment DNV 2.7-1 enclosure.

“Ex SCS™ quickly and reliably triggers a safety shutdown on detection of a flammable gas in the engine air inlet, diesel engine over speed, high exhaust gas and coolant temperatures, low oil pressure or if there is a manual emergency stop activation for example,” says Rob, explaining that the control system is Category 2G certified for Zone 1 use, ATEX and IECex, and is also SIL 2 rated to EN61511.

Ex SCS™ is a 100% stand-alone safety control system for ATEX 2014/34/EU compliance. A 7inch colour touchscreen HMI (Human Machine Interface) displays the current safety status and the diesel engine control and monitoring screens can also be integrated. This makes it easy to incorporate additional driven equipment controls such as pumps, generators, transmissions, or the well head platform’s DCS (distributed control system).

“Whichever solution is chosen, operators are no longer exposed to sources of ignition if a ‘dummy arrestor’ is used,” Rob says. “Manual handling compliance issues also disappear because we have taken away the need to change and clean the heavy flame arrestors which are typically located above waist height.”

Following extensive field trials and testing, and the completion of the EN1834-1:2000 non-flame transmission tests, both solutions are available to order now for Pyroban kits and HazPaks™ all over the world.

“Operators can now get on with the job, enjoy longer operation and reduce unproductive downtime,” he adds.

A free white paper containing information about eliminating the exhaust flame arrestors from ATEX diesel engines is available at

Call +44 1273 456825 or email for more information.