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We can perform a variety of non-destructive testing in house. These tests are fully certified and are often witnessed by a third party. We have created bespoke test certification showing full results, meaning that our certification is clear and easy to understand.


We have a bespoke hydrotest rig on our premises with the ability to test a range of fittings up to 15,000PSI. We have the potential to perform any duration of test from one minute to seven days. All tests are digitally recorded using calibrated sensors, so all tests are stored and graphs of the test can be created and included with the test report if required. Testing is done using the local water supply but we can also test using demineralised water by request where chloride levels must be strictly controlled.

Hydrotesting is carried out at 1.5 times the pressure rating of the part and/or its material. Acceptance Criteria - ANSI B16.5 and ASME 31.3


Positive material identification (PMI) can also be performed at John Mayes. Our operators can identify a wide range of steels from Low Alloy Carbon, Ferritic Stainless, Ferritic-Austenitic, Austenitic, Martensitic, and Nickel Alloy steels. Typical grades are F5/P5, F9/P9, F91/P91, 316/316L, F51, F53, F55, F44, Alloy 625, Alloy 825 and Alloy C276. We test using a Niton XRF portable instrument; this gives us the ability to analyse the material and provide you with complete certification which lists all elements identified by our equipment.

For jobs where XRF is not a suitable method of analysis, we can arrange an external supplier to perform OES – Optical Emission Spectroscopy.


We manufacture a lot of Duplex and Super Duplex machined components and welded assemblies. As such we have the need to monitor the ferrite levels in the steel, particularly with weldments where poor manufacturing controls can ruin the steel microstructure. To accurately monitor our processes we use a Fischer Feritscope FMP30. This is the industry recognised best comparative test instrument for the job. Fully detailed test reports are produced for the client.


With so much of the piping industry now dealing with Sour environments, hardness testing has become a more common project requirement. We use a portable GE UCI and Rebound machine to verify forging and weld area hardness. Fully detailed test reports are produced for the client.

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