Onsite and Offsite Services

Visual Examination of welds is sometimes not associated with non destructive testing, but it is the most widely used method within the fabrication & welding industry. Visual Welding Inspection activities will find surface breaking indications and welding profile imperfections.

All fabrication standards require visual inspection to be performed and various application standards would have varying levels of allowable imperfections.

Visual inspection requirements in standards such as EN 1090 / ISO 3834 / ISO 17637 etc require inspection at three stages. Before, during and after welding.

The criteria would have a specific pass or fail criteria, thus visual inspection is as important as any other specified method. In some cases, the visual examination will identify such issues that would affect, for example, the fatigue life of a product in service.

Sure Check can assist with all stages of the inspection activity, especially when some clients and / or specifications may require and independent organization with suitably certified staff to perform a final visual inspection to ensure compliance with the specified requirements.

Magnetic Particle Testing (known as MPI or MT) is sometimes specified in addition to visual examination on welds. They are used to find any imperfections that may not be immediately visible to the naked eye or where a small amount of assisted magnification is used.

How does it work and limitations to be considered
MPI / MT is particularly sensitive to surface-breaking or near-surface imperfections such as cracks, even if the crack opening is very narrow. However, if the crack runs parallel to the magnetic field, there is little disturbance to the magnetic field, and it is unlikely that the crack will be detected. For this reason, it is recommended that the inspection surface is magnetised in two directions at 90° to each other. Alternatively, techniques using swinging or rotating magnetic fields can be used to ensure that all orientations of crack are detectable.

MPI / MT cannot however be used to detect deeply embedded flaws, nor can it be used on non-ferromagnetic materials, such as aluminum, copper or austenitic stainless steel.

The MPI /MT method of NDT is also widely used on forgings, mechanical fixings such as bolts, castings and other product forms that have a ferromagnetic capability.

For some product forms Sure Check can utilise our bench units and apply fluorescent techniques for improved sensitivity.

Standard yoke methods can be performed both at our Cannock premises or on site at our customers nominated locations.

Radiographic Testing (RT) is a non destructive examination technique to view the internal structure of a component. RT is often used to inspect machinery, such as pressure vessels and valves, used to detect flaws, weld repairs, weld tests and more. Surecheck specialise in volumetric testing techniques (RT) and offer a range of bespoke radiographic services delivered by an experienced team qualified to PCN level II & III.

Our technicians operate within our own well-equipped facility based on Hawks Green Business Park in Cannock, we have three X-Ray bays available that accommodate various shapes and sizes and can handle up to 2.5 ton in weight.

On a daily basis we X-ray welder qualification test pieces, welding procedure test pieces, pipework spools and vessels of all sorts of shapes, sizes and materials. Our X-ray machines are capable of penetrating thickness of up to 50mm.

We can provide testing at client premises subject to a risk assessment. This can can potentially provide more options to our clients.

Our in house X-ray and and film processing facilities provide us with the ability to complete work during day time hours in a timely manner to suit customer requirements.

The standards that we regularly work in accordance with are BS EN ISO 17636, BS EN 1435 or ASME IX and assess the radiographs in accordance with a range of standards, including BS EN ISO 9606, BS EN ISO 15614, ASME IX, BS EN ISO 5817 or ASME IX. Application / construction standards also include BS 2633, BS 4677, EN 13455 etc.

Dye Penetrant Testing (known as DPI or PT) is sometimes specified in addition to visual examination on welds. It can be used to find any imperfections that may not be immediately visible to the naked eye or where a small amount of assisted magnification is used.

How does it work?
Firstly, the surface to be inspected is cleaned thoroughly to remove all traces of dirt and grease.

A brightly coloured or fluorescent liquid is then applied liberally to the component surface and allowed to penetrate any surface-breaking cracks or cavities.

The time specified for the liquid to soak into the material’s surface is normally about 20 minutes. After soaking, the excess liquid penetrant is wiped from the surface and a developer applied.

The developer is usually a dry white powder, which draws penetrant out of any cracks by reverse capillary action to produce indications on the surface. These (coloured) indications are broader than the actual flaw and are therefore more easily visible. DPI / DT can be performed in all positions and does not need to be the gravity position.

There are several different liquid penetrant systems used in industry. Fluorescent penetrants are normally used when the maximum flaw sensitivity is required. However, these penetrants must be viewed under darkened conditions with a UV lamp, Surecheck can offer dye penetrant testing at our premises in Cannock.

The more commonly used systems are solvent removable, or water washable, red dye systems, which typically comprise three aerosol cans – cleaning fluid, penetrant and developer. These systems are often used to check weld quality during fabrication. These methods can be offered on or off site.

Important Considerations
Despite being one of the popular Non-Destructive Testing methods, liquid penetrant testing is often misused and spurious results can be obtained which are mainly down to operator error.

Some of the most common errors are: Test surfaces are not cleaned adequately, the contact time between the penetrant and the test surface is too short, or the excess penetrant is removed carelessly (i.e. from flaws as well as from the test surface). For these reasons, it is important that personnel carrying out liquid penetrant inspections are properly trained and qualified (for example, in accordance with the British Institute of Non-Destructive Testing’s PCN certification scheme or equivalent schemes such as those operated by CSWIP and ASNT).

Ultrasonic Testing is generally termed as a volumetric method. It is primarily used to find internal imperfections in welds or other product forms such as forgings, plate sections

It can sometimes be specified to ensure no laminations are present in materials that are to be subsequently welded in highly stressed joint configurations or, even after welding has taken place, to ensure imperfections such as lamellar tearing have not occurred during the welding operation.

How does it work?
A strong specular reflection is required to resolve a flaw response from the background noise level with pulse echo ultrasonics. For planar flaws (cracks, lack of fusion, etc.) a specular reflection will only result if the ultrasonic beam is normal (or near normal) to the plane of the flaw. Angled beam shear wave probes are commonly used for the manual ultrasonic inspection of welds in ferritic steels, as these provide the only way of directing ultrasound into the weld body when the cap reinforcement is still present. Where a weld cap restricts probe movement, the sound can be reflected off the bottom surface and directed into the weld body under the cap.

Where sound is angled directly at the area of interest, this is referred to as “half skip testing”. “Full skip” testing occurs when the bottom surface is used to reflect the sound before it enters the weld.

For a typical girth weld, a 45° probe is used for inspecting the root region, and 60°/70° probes for the sidewall fusion faces and weld body. The behaviour of the echo-dynamic pattern and shape of the flaw response (with respect to probe movement) can be used to identify the type of flaw, estimate the length and, in some cases, the through-wall height of the flaw.

What will it find?
Most manufacturing flaws (lack of sidewall fusion, lack of root fusion, lack of root penetration, porosity, solidification cracking, etc.) and in-service flaws (fatigue cracking, stress corrosion cracking, etc.).

Where is it used?
Inspection of welds made in both ferritic and non-ferritic metals in pressure vessels, pipework, storage tanks, bridge structures etc.

Our UT services can be offered on or off site to suit our customer’s needs.

Positive Material Identification (PMI) can be carried out using our XRF (X-Ray Fluorescence) handheld gun. We can quickly and accurately identify a wide range of metallic alloys. Our class leading Niton XL2 Plus analyser delivers fast and accurate semi-quantitative results.

The PMI testing can be offered at our clients premises or at our Cannock Non Destructive Testing facility.

PMI testing can identify material grades of metallic materials including:

• Stainless steels
• Duplex Stainless Steels
• Copper
• Nickel alloys
• Aluminium
• Titanium
• Exotic alloys
• Precious metals

Ferrite inspection is a fast, non-destructive test method used to measure the amount of delta ferrite content in Austenitic stainless, Duplex stainless steels and Austenitic weld metals. It is a widely used method to ensure the correct levels of ferrite are present in both parent materials and weld metal deposits.

Ensuring that materials have the correct amount of ferrite is vital. If the specified levels are incorrect, this can have a detrimental effect on the service life of a part, it’s corrosion resistance and overall durability. Additionally, when ferrite levels are outside the specified range in stainless steel weld deposits it can become susceptible to hot cracking. Ferrite testing is key in determining that the amount of ferrite is within specified limits in contract specifications and certain construction standards for some products.

Ferrite inspection is a common specification requirement in the manufacture of pressure vessels, pipework, storage tanks etc.

Our market-leading portable Fischer FMP30 Feritscope is capable of measuring the ferritic content, expressed as either percentage (%) quantity or FN (Ferrite Number) in a vast range of components, large or small. Our Ferrite Inspection service can be performed at customer sites anywhere in the UK, or at the Surecheck facility in Cannock.

Surecheck can also offer the services for qualifying your Coded Welding Procedures and Coded Welders.

Welding Qualifications can be carried out in accordance with any of the following standards: BS EN ISO 15614-1, BS EN ISO 15613, BS EN ISO 15614-7 or 8, BS EN ISO 9606 or ASME IX. Other standards can also be applied as and when requested, these include AWS D1.1, etc.

Working with one of the BEIS approved bodies, we can offer UKAS accredited coded welding certification.

We’re aware that the welding qualification standards can be quite complex. So please do not hesitate to contact us to discuss your individual welding qualification requirements. We can discuss your individual needs in more detail with our certified welding or senior welding inspector.