Inspection & NDT

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AXIOM operates a fully accredited inspection and NDT service offering. We are the inspection authority to a number of blue-chip companies and our expertise is used across the UK, Continental Europe and Asia to help keep assets safe and compliant. Teaming up with the expertise and knowledge of our in-house materials and mechanical engineering departments, we offer a class-leading inspection service to industry.

We possess a wealth of knowledge and experience in integrity management and support companies to deliver this inspection through our mechanical and materials engineering services.

We assist interpreting UK regulations to ensure you meet our client’s expectations of the Health, Safety and Environment across to integrity management for PSSR, COMAH and PUWER.

AXIOM also offers a broad range of Non-Destructive Testing (NDT) techniques, holding UKAS accreditation to ISO/IEC 17020 for a number of these techniques. Our NDT personnel have a wealth of experience and are qualified to PCN levels 1, 2 and 3 to BS EN ISO 9712.

Our accreditation is limited to those activities described on our UKAS schedule of accreditation found here.

Take a look at our inspection service offerings for further details on how we can help you.

For the life cycle of an asset, it is important that the asset is operated safely and efficiently.


  • Preparation and certification of Written Schemes of Examination (WSE) for Pressure Systems Safety Regulations (PSSR) and Non-PSSR assets.
  • Corrosion (Deterioration mechanism) assessments
  • Risk-Based Inspection analysis
  • Non-Invasive Inspection assessment
  • PSSR Asset assessment for postponing inspections
  • Design verification assessment and design verification certificate
  • Fitness for service, life extension, remaining life and engineering criticality assessment
  • Weld procedure approval
  • Asset management database for data storage, monitoring and control
  • Performing NDT, field in-service and out of service inspections.

Risk-based inspection (RBI) is a decision-making process which assists with the production of inspection programs.


AXIOM can provide experienced and competent people to assist with the following

  • Qualitative and semi-quantitative RBI analysis for process equipment including but not limited to vessels, tanks and piping
  • Criticality analysis to determine the extent of the RBI assessment
  • Bespoke risk- based methods depending on client needs
  • Corrosion assessment and management plans
  • Specification of optimised inspection intervals.

Our bespoke Asset Management Database (AMD) is the central point for clients to access all documentation produced by our company. Every inspection, assessment, engineering design, calculation or failure analysis undertaken out on your equipment is recorded in the AMD. 

Every asset has a record card where all documents associated with that item are located. This provides the client with all necessary data, relating to individual assets. 

The advantages of having internet access to your records are: 

  • Having instant access to your records at any given time 
  • The database is provided free of charge to clients that engage with Axiom 
  • Key Performance Indicators and compliance with UK Regulations and your own integrity management programme 
  • Receiving access to monthly management reports detailing work undertaken and condition of your assets 
  • Having access to your inspection records in different ways – e.g., group all your piping system records together or look at all your records per plant area 
  • Rank your equipment in order of risk so you can focus your inspection efforts on high-risk items 
  • Accessing all actions identified during the inspection and track them through to completion 
  • Grouping actions together to obtain budget estimates for asset life planning 
  • Submitting your own documents online as a repository for all activities to do with your specific equipment 
  • Linking equipment together as associated items – if one area is affected you can investigate to see which other equipment could be potentially affected 
  • Receiving online notifications to your email inbox when inspection reports have been completed or your endorsement is required for reports with hyperlinks to the records in question 
  • A secure database requiring username and password access which is given on a per-user basis so that access to individual databases remains secure and tightly controlled 
  • As the AMD has been developed in-house, we can adapt and make changes to suit our client’s requirements with our system developer 

Our certified inspectors carry out above ground storage tank inspections in full accordance with EEMUA 159 regulations and standards. 

Prior to any tank inspection, we produce a Written Scheme of Examination (WSE) detailing inspection requirements and any additional needs over and above the EEMUA 159 guidelines. 

Where tanks do not fall within the scope of EEMUA 159, we will develop a focused WSE, based on our in-house guidance documents and the guidelines set out by EEMUA ensuring industry best practice is adhered to at all times. 

Where defects or non-compliance is identified we offer a turnkey mechanical service that provides the course of action toward compliance. 

Typical issues that can occur include: 

  • Tank lean from the vertical 
  • Settlement of foundations 
  • Local and generally thinned areas 
  • Structural integrity concerns 
  • Repairs, modifications and welding procedures 
  • Other services associated with storage tanks 
  • Assessment of non-codal compliant tanks 
  • Assessment of previous repairs which may fall outside of codal requirements 
  • Corrosion management 
  • Inspection and assessment of linings 
  • Specifying repair procedures and welding requirements 
  • Material of construction compatibility with stored products 

Inspection reports are written and uploaded on to our Asset Management Database (AMD) and accessed via a web portal. This ensures companies can access their records from anywhere in the world at any time. 

AXIOM carries out in-service process equipment inspections to meet the requirements of the Pressure Systems Safety Regulations 2000 (PSSR) for Major, Intermediate and Minor pressure systems. We have UKAS accreditation for: 

  • Development & Certification of Written Schemes of Examination (WSEs) 
  • In-service inspection 
  • Inspection of repairs and modifications 
  • Non-Destructive Testing (NDT) techniques MPFD, DPFD, MFL, ECFD and USTT 

With a wealth of experience and in-depth technical knowhow, we develop focused Written Scheme of Examinations that identify deterioration that could lead to failure of equipment. The WSE takes into account the operating conditions and extends the inspection beyond minimum requirements of PSSR. This provides additional assurance required for high hazard sites covered by the COMAH Regulations and satisfies the requirements of the HSE in relation to Ageing Plant. 

Where a more detailed study of the equipment is required a Risk Based Inspection approach can be undertaken. 

All our Inspectors have NDT qualifications enabling us to undertake this function whilst carrying out the inspection work reducing overall cost. 

With all data available online, clients are reassured they can access their records from anywhere in the world at any time. Alongside these records we provide you with: 

  • The facility to trend NDT data 
  • The ability to submit your own records online 
  • The capacity to sign off documentation using a digital signature 

In doing so, our clients benefit from an efficient and effective inspection data system available 24 hours a day, seven days a week. 

AXIOM carries out in-service and out of service inspection of piping systems to met the requirements of Pressure Systems Safety Regulations 2000 (PSSR) for Major, Intermediate and Minor pressure systems. We also carry out inspection of terminal piping utilising API 2611, API 570. 

Written Schemes of Examination are produced taking into account the operating conditions, process fluid, system location and any possible deterioration mechanisms. 

AXIOM can carry out inspections to existing Written Schemes of Examination if required by the client.  

Isometric drawings of the piping system are produced showing start and end points, piping supports and connected equipment. NDT test points are annotated to allow repeatability of the readings. 

Piping systems, and their features can be geolocated, this is especially useful for cross-country pipelines where defects can be difficult to locate 

Our inspectors hold API 570 qualifications and most hold current NDT certification. 



Non-destructive Testing (NDT) consists of a variety of non-invasive inspection techniques used to evaluate the properties of a material, component or weld without affecting its integrity.

Additionally NDT can assess assets integrity, monitor previously identified damage mechanisms, and also make informed decisions for remaining life evaluations.

NDT can be used on a variety of applications such as:
• Pressure vessels
• Piping systems
• Storage tanks
• Power generation
• Aerospace

These techniques can be used to find, size and locate surface and subsurface flaws and defects; such as porosity, corrosion or cracks.

A number of critical factors determine which NDT technique to use, such as:
• The material
• Its geometry i.e. complex parts
• Desired outcome
• Cleanliness of equipment
• The environment

In MPFD a magnetic field is established within a ferromagnetic material which is capable of identifying surface and slightly subsurface discontinuities when a suitable detection media is applied.
Any discontinuities perpendicular to the magnetic field direction (testing is carried out in two directions to ensure full coverage) will result in a flux leakage whereby the magnetic particles will be attracted to this area and produce a visible indication.

Detectable Indications:

  • Cracks
  • Porosity
  • Seams
  • Laps


  • Rapid and simple process.
  • Immediate results.
  • Capable of locating surface and near surface indications.
  • It is portable.
  • Relatively inexpensive.
  • Complex parts can be tested easily and very quickly.


  • Can only be used on ferromagnetic material.
  • Majority of test methods require a power source.
  • Paint needs to be removed prior to inspection.
  • Demagnetization and post cleaning is sometimes a requirement.


  • DPFD
  • ECFD

The principle of DPFD is that penetrant is drawn into any potential surface-breaking discontinuities by capillary action with any excess surface penetrant then removed from the surface; a developer is then applied, to draw out any penetrant that has been drawn into any potential discontinuity and thus producing a visible surface indication.

Detectable Indications:

  • Cracks.
  • Porosity.
  • Seams.
  • Laps.


  • Very sensitive.
  • Can be used on both magnetic and non-magnetic materials.
  • No power source is needed.
  • Large surface areas can be tested.
  • Complex parts can be easily tested.
  • Indications are produced directly on surface of the part providing a visual image.
  • Equipment investment is minimal.
  • Can be used on both ferrous and non-ferrous material.


  • Detects only surface breaking defects.
  • Surface preparation is critical as contaminants can mask defects.
  • Post cleaning is necessary to remove chemicals.
  • Requires multiple operations under controlled conditions.
  • Chemical handling precautions are necessary (toxicity, fire, waste).


  • MPFD
  • ECFD

Ultrasonic testing uses high frequency sound waves to penetrate through a material, with the subsequent received signal back indicating the materials condition and any discontinuities.

Ultrasonic testing can be used to in a variety of uses:

  • Material thickness checking.
  • Flaw detection.

Detectable Indications:

  • Laminations
  • Inclusions
  • Cracks
  • Porosity
  • Lack of fusion
  • Bond integrity


  • Detects surface and subsurface (internal) defects.
  • High depth of penetration.
  • High accuracy with regards to discontinuity size, shape and location.
  • Instantaneous results.
  • Access is required from one side only.


  • High degree of operator skill required.
  • Couplant is required to negate air gap between the probe and test surface.
  • Surface roughness, complex geometries, small parts or exceptionally thin materials are difficult to inspect.
  • Linear defects oriented parallel to the sound beam go undetected.
  • Very thin sections can prove difficult to test.


  • Radiography

Eddy-current testing uses the principle of electromagnetic induction and is capable of locating surface and slightly subsurface discontinuities, coating thickness measurement and metal sorting by grade.

Detectable Indications:

  • Cracks.


  • High sensitivity to small discontinuities at or near the test surface.
  • Can be used on ferrous and non-ferrous material.
  • Inspection gives immediate results
  • Portable
  • No coupling media required
  • Inspects complex shapes and sizes of conductive materials
  • No need to remove paint.


  • Only conductive materials can be inspected
  • Surface must be accessible to the probe
  • Skill and training required is more extensive than other techniques
  • Depth of penetration is limited.
  • The wide range of parameters which affect responses means that the signal from a discontinuity can be masked by an unwanted parameter, e.g. hardness change.
  • Testing is restricted to locating surface breaking and slightly subsurface discontinuities.



The principle of MFL consists of saturating a component with magnetism to a level whereby a reduction in material thickness causes sufficient distortion of the internal magnetic field allowing lines of flux to break the test surface at the site of the discontinuity.

Detectable Indications:

  • Underfloor corrosion.
  • Top side corrosion.


  • Detects surface and subsurface flaws.
  • Simple, no elaborate electronics.
  • Low cost and rapid.


  • Works only with ferromagnetic materials.
  • Demagnetization of specimen may be required after testing.
  • Some operator experience is required to adequately administer the technique and interpret the results.


  • Radiography

Radiography services are delivered via our external partners.

Radiography uses a radioactive isotope (X-rays and gamma-rays) in order to produce an image of an object on film or in a digital format, which is usually to scale.

If a radioactive source is placed on one side of a component and a film on the other side, an image is obtained. This will show density variations i.e. discontinuities or thickness variations within the specimen.

Detectable Indications:

  • Porosity.
  • Inclusions.
  • Voids.
  • Wall thickness measurement.
  • Corrosion mapping.


  • A variety of material types with varying density can be tested.
  • Fully assembled components can be tested.
  • There is minimum surface preparation required.
  • Capable of detecting both surface and subsurface defects.
  • It provides a permanent record of the test.


  • High level of safety precautions are required.
  • Access is required to both sides of the component.
  • Orientation is critical.


  • UT

Supporting the Asset Life Cycle