Press Releases

SGS has announced the installation of a state-of-the-art freezer chamber at its Ex testing laboratory in Buxton, Derbyshire. The new freezer is capable of operating down to -70°C and is large enough to contain bulky equipment, such as a 630 frame-size motor, rated at 3 MW. The new testing chamber will allow the motor to be switched on and rotated at full speed, in extreme climatic conditions, before an explosive gas atmosphere is ignited within the motor at a low temperature.

Until recently, it was only necessary to test such equipment to minus 50 degrees, but with the advent of more oil exploration in arctic areas, this has fallen to minus 65 degrees. The installation of this new chamber is therefore an investment in the future, allowing SGS to remain at the forefront of Ex testing and maintain its position as the world’s leading certifier of equipment intended for installation in hazardous atmospheres.

Practical testing at the actual minimum ambient temperatures is required because there is no single mathematical equation that can be used to replicate the way explosions develop in complex shapes. To maintain the “flameproof” protection concept for Ex Equipment, it is necessary to find the maximum potential internal explosion pressure by test, before a subsequent hydraulic over-pressure test. This ensures that the equipment enclosure will not burst. Lower ambient temperatures mean a greater number of gas molecules can fit into a given enclosure size. If ignition occurs, the final pressure is therefore greater – i.e. multiplied by the increase in the amount of gas.

After the hydraulic over-pressure test (sometimes with internal pressures in excess of 100 bar) the enclosure is subjected to the test for “non-transmission” where the enclosure has the gas atmosphere both inside and outside, and an internal ignition must not ignite the outside atmosphere.

Performing such tests requires expert understanding, high levels of precision and the latest technology. SGS has carefully worked safety procedures for such gas explosions, which, although they sound dangerous, are actually far more predictable than “short-circuit” tests performed on batteries and cells for portable equipment. In these cases, when the internal protective devices have been removed in accordance with the standard for Intrinsic Safety protection, the cells can register temperatures of over 500°C. Often, it is necessary to employ special “lithium” fire extinguishers to quell the flames.

SGS is highly experienced in advising companies on Ex testing. They are prolific in issuing European ATEX Directive Certificates and have issued more international certificates in the IECEX Certification System than any other laboratory in the world. In addition, where local certification is required, for example in Brazil or Russia, the SGS Baseefa IECEx Certificate and Report can be used to underpin the local certification.

To learn more about SGS Explosive Atmosphere Services.

For more information, please contact:

Carolyn Featherstone

Business Development Manager

Tel: +44 01 298 76 66 00

Ron Sinclair

Technical Manager

Tel: +44 01 298 76 66 00



About SGS

SGS is the world’s leading inspection, verification, testing and certification company. SGS is recognized as the global benchmark for quality and integrity. With more than 95,000 employees, SGS operates a network of over 2,400 offices and laboratories around the world.