The questions and answers that ensure Ex rated equipment stays hazards safe

First question: Does the repair provider follow the international repair standard, BS EN IEC 60079-19:2019?

The answer should, of course, be yes. When end-users send hazardous area equipment away for repair, overhaul, or reclamation, it is essential that they understand their responsibilities, as it is their equipment, and they will be fitting it into a hazardous area on its return. Written within the international standard is the definition of a user as “primarily responsible for the repair”.

If the repairer does not use the international Ex repair standard or follow its guidelines, the user is primarily responsible for this. So, end-users should understand this standard, be able to ask the correct questions of a repairer, know what documentation to expect, and be confident the Ex equipment has been returned fit for purpose.

Next, ask: who is the repair provider's responsible person? The responsible person at a repair facility is the person that checks the operatives work, creates the paperwork and obtains the correct standards for the equipment in question. They also issue the documentation for the end-user to agree on the work to be carried out and are responsible for ensuring it is carried out to the correct specification.

The responsible person and the end-user should be in close contact throughout the time the equipment is in the repair facility, and so it is important for the repair provider to identify a competent, responsible person. End-users should also ask a repair provider what quality management systems they use.

A quality management system is part of many workplaces, but traceability is vital when looking at Ex equipment repair. The international repair standard requires repairers to keep documentation on all Ex repairs for a minimum of ten years. If an end-user had an incident at its plant, would it be confident that it could produce the documentation for a repair? If not, could it be confident that the repair facility it used could issue it for a repair it conducted eight years ago? If the repair facility uses a recognised quality management system, this will give the confidence that the documentation will be available if needed.

It is also important to establish whether staff training certificates are still valid. The international Ex repair standard states that staff involved with Ex repairs should undergo training and assessment at intervals not exceeding three years. To comply with this requirement, AEMT members trained in the repair of Ex equipment have their training certificates refreshed every three years.

Finally, it is crucial to affirm whether the repair facility’s measuring equipment is traceable and adequately calibrated. It is important to have complete confidence, backed by documentation, that the repairer only uses calibrated measuring equipment – for both electrical and mechanical measurements. Not only should the equipment be calibrated, but the repairer should be sure that the equipment was measuring correctly at the time of use. There should also be a record of which vernier, micrometre, surge tester etc was used to measure the end-user’s equipment. As mentioned earlier, traceability is a vital part of any repair, but when the equipment can cause a major incident, traceability and responsibility become a necessity.

The surest way to ensure a repair facility is competent in the repair of Ex rated equipment, meets the international standard, and gives the correct answers to the questions outlined above, is to choose a repairer from the AEMT’s Ex register. All companies listed on the register have been trained in Ex equipment repair to the International and European standards BS EN IEC 60079-19, and have been assessed as competent.

Karl Metcalfe is technical support at the Association of Electrical and Mechanical Trades (AEMT)