Case study: Tim Walker – CompEx Ex01-Ex04 Gas and Vapours qualification

Tim Walker

Tim Walker is part of the team at the UK’s largest onshore drilling contractor, Marriott Drilling Group. Working within a split role, Tim is a rig electrician on oil and gas/ geothermal/ water well operations, as well as helping to manage the well development and testing division of the company.

The CompEx qualification

Within this industry, there is a requirement when working on specific projects that some of the electrical installation fall within zone 1 and 2 following API505 standards. Additionally, it is crucial that electricians hold the relevant certification to work within the potentially explosive atmosphere.

Meeting the criteria of being an electrical technician who is involved in installing, inspecting and maintaining certified Ex electrical equipment in a location where gases and vapours can potentially create a hazardous area, Tim registered for the CompEx Ex01-Ex04 Gas and Vapours qualification.

Tim comments that, “The qualification had come highly recommended, as other operatives within our company had previously completed the training with CompEx and they had nothing but good things to say.”

Opting to take the five-day qualification at a centre in Newcastle, Tim learned about the safety considerations that should be applied to work areas that contain potentially explosive atmospheres and the factors that are used to classify their location.

Broken down into four units, the course included instruction on how to read hazardous area classification documents, equipment labelling and documentation, and also informed Tim and the other candidates about the main protection concepts, ATEX categories and Equipment Protection Levels that are applied to certified Ex electrical equipment.

The experience

Tim comments, “My experience was very good. Having done a lot of training courses in the past due to the nature of my work, this was by far the most challenging. Usually, I would not have to do any revision or night-time studies to pass a course, this however, was very different and if you did not fully apply yourself it would be very difficult to pass.

“My tutor for the theory side of the qualification, Gareth, brought his vast knowledge of the course and the industry into the classroom which comprised of a total of six candidates. In what sometimes was a seemingly difficult piece of literature to get your head around, Gareth put the situation into context by adding real life scenarios from his past experience which made it much easier to understand the context.

“Byron, who led on the final two days for the practical and theory test, was also a fantastic assessor. We were all obviously very apprehensive about the test, but Byron, with his calm and relaxed attitude, told us that we had the knowledge and to apply it and not to rush and not to get overly phased by it. It worked a treat!

“My knowledge of ‘Ex’ requirements has vastly improved since doing the course and by working within the industry afterwards. Having a good base knowledge also tends to make you think about situations where they could be a requirement for Zoning and ‘Ex’ rating equipment, whereas previously I would have not had the knowledge to comprehend this – I would really recommend the CompEx Ex01-04 qualification”.

For more information about the Ex01-Ex04 Gas and Vapours qualification and to find your nearest centre, visit

Back to top of page