Non-electrical equipment for explosive atmospheres Ex h (c, b or k)

Testing techniques   

Various tests are specified in standards ISO/IEC 80079-36 and ISO/IEC 80079-37 that need to be applied on non-electrical equipment. These tests are directly related to the safety of the product to ensure that control measures are applied to the equipment, so that possible ignition will not become effective or lead to an explosion.  

These products generally have their own potential ignition sources or have an energy source that transfers or stores without use of electricity, such as: 

• bearings 

• couplings 

• pumps 

• gearboxes 

• brakes 

• hydraulic and pneumatic pumps 

• various machine, fan, engine, compressor, assemblies. 

All equipment will be subjected to a formal documented ignition hazard assessment to identify all potential ignition sources that can occur. 

The tests that are defined and preformed are based on the risk assessment findings and they verify that the applied control measures are effective and they will reduce the likelihood of a potential ignition source becoming an effective ignition source.  

Here are some potential ignition sources:  

• hot surfaces 

• flames and hot gases 

• mechanically generated sparks 

• electrical source 

• stray electric currents 

• static electricity 

• lightning 

• radio frequency electromagnetic waves 

• electromagnetic waves including optical radiation 

• ionizing radiation 

• ultrasonic 

• adiabatic compression and shock wave 

• exothermic reaction, including self-ignition of dusts 

Testing to standards 

The International standards ISO/IEC 80079-36 and ISO/IEC 80079-37 specify basic methods and requirements for design, construction, testing and marking of non-electrical equipment and Ex components. 

Information requirements   

We will need the following drawings/documents from the manufacturer: 

• technical description of the equipment with details on intended use

• materials and their characteristics

• design drawings and specifications, results of calculations

• assumptions such as loads, strengths, safety factors

• results of tests and examinations carried out 

• instruction for installation, operation, and maintenance

• risk ignition hazard assessment performed by the manufacturer 

Types of protections 

There are three types of protections: 

• constructional safety ‘c’ - ignition protection where constructional measures are applied to protect against possibility of ignition from hot surfaces, sparks and adiabatic compression generated by moving parts 

• control of ignition source ‘b’ - ignition protection where mechanical or electrical devices are used in conjunction with non-electrical equipment to manually or automatically reduce the likelihood of a potential ignition source becoming an effective ignition source 

• liquid immersion ‘k’ – type of protection where potential ignition sources is made ineffective or separated from the explosive atmosphere. Either totally immersed in a protective liquid, or by partially immersing. Then continuously coating their active surface with a protective liquid in a such way that an explosive atmosphere which may be above the liquid, or outside the equipment enclosure, cannot be ignited.

Getting the test results

The results of our testing are presented in a test report that is endorsed by our local Australian laboratory accreditation body, NATA (National Association of Testing Authorities, Australia).

When product sample testing, design assessment (Ex test report) and quality assessment (quality assessment report) are successfully completed, an Ex Certificate of Conformity (IECEx or ANZEx) is issued by TestSafe.

Help and support

Complete our online enquiry form.

Call: +61 (2) 4724 4900

Email: testsafe@safework.nsw.gov.au

Mail us at: PO Box 592, Richmond, NSW 2753 Australia.