External Non Destructive Testing / Pipe work condition assessment

API offers the latest technology to scan external pipe work assets; from this we can measure internal/external pit depths, wall thicknesses, ageing and corrosion levels.
Utilising a specialist assessment system, an ultrasonic delivery driver is attached to the pipeline, the site technician measures the pipe circumference at this point and inputs the data into the software system. Ultrasonic probes are coupled on the pipeline and water jets immerse the probes during the scanning function and accurately measure the pipe wall thickness of the pipe.
The system then traverses the pipeline giving thousands of wall thickness readings for a detailed report production.

Additional tests are also undertaken on site including soil resistance levels, temperature and soil sampling.

This information is then processed by our data analyst utilising the data life expectancy is calculated. This is put into a full data report presented to our client in a paper/digital format.

NDT Testing of Commercial Pipe Networks

API offers NDT testing on commercial heating and air conditioning pipe networks. The pipe testing service enables a client to fully understand its pipe condition prior to extensive pipe rehabilitation, replacement or prior to the installation of new boilers or cooling systems. This in turns gives a client peace of mind that money is being spent where required.

API to date has undertaken NDT testing for:

• Major UK Airports
• Major UK Universities
• MOD Bases UK
• NHS Hospitals
• The Palace of Westminster
• TATA Steel UK
• Toyota Car Plant UK

All NDT tests include the provision of a detailed pipe testing report to include pit depth measurement, macro photography, condition assessment results, pipe wall thickness measurements and a calculative remaining life expectancy.

Material Sampling and testing

API is fully supported by an accredited laboratory to analyse samples supplied by clients testing to include:

• Material preparation and shot blasting
• Wall thickness testing
• External/Internal pit analysis
• Corrosion mapping
• Hardness value testing
• Microstructural assessment
• Macro photography

All of the test are collated and presented in a full detailed report

Pipe In-situ Testing / Surface Replication

Acetate replication is an established technique in faithfully copying the micro-structure of a material on to a film. This means a material can be examined in a laboratory without sectioning or damaging the area of interest. This surface procedure is used to identify a material, look at the quality of a material or examine a particular area of interest such as a weld or joint.

A small area of the sample is prepared using a 600 grit paper, 120 grit paper and a cloth impregnated with a 1 micron diamond polishing paste. The area of interest is then etched to reveal the micro-structure. Once sufficient etching has occurred, a thin film of acetate film is applied using acetone, a spray and double sided tape. This process is finalised by adding the replica to a glass slide for examination under the microscope by our experienced analyst.

Existing Water mains

A large amount of water mains have been in service for many years, however through type of materials used, age of mains and backfill type these mains are now failing causing water loss, discolouration issues and eventually complete failure.
Through experience on pipe networks around the world, API has highlighted the fact that in most cases, it is actually the pipe joint that is failing prior to the pipe itself, and therefore would recommend an acoustic testing approach on the entire pipeline and on all joints, from this data the correct planning can be put in place with pre-determined points of interest being exposed and tested.
Many utilities do undergo a system of on-going monitoring of these assets, however the location chose to test is typically solely down to a pre-determined measured point on the pipe, or area with ease of excavation access.

The on-going testing of pipelines should be approached in the following order:

1. A full asset investigation and leakage sweep
2. Planning of true excavation locations from data obtained
3. External scanning of highlighted areas only (remove the guess work)
4. Internal scanning to cover further distances and highlight defects in difficult to access locations i.e. under rivers/roads etc.

A full asset investigation and leakage sweep

API offers a full service of pipe inspection and acoustic leak detection surveys to monitor internal condition within a live water pipeline. The surveys offer detailed analysis of pipelines with actual knowledge resulting in the correct course of pipe rehabilitation.

Ongoing Pipe Monitoring
Pipe locations with a frequent burst history, or for high risk locations ie river and road crossings. API can offer ongoing monitoring of these areas using a wide array of pipe inspection Technologies.

The installation of the Pipeline^TM in-line cabling system enables a rapid response to pipe inspection and leak detection without the need for any flow within a pipeline.

Planning of true excavation locations from data obtained

A full condition assessment can be obtained after post analysis of the live CCTV/Hydrophone inspections.
All visual and acoustic points of interest will be logged and highlighted prior to any excavations in order to maximise the overall value of external scanning by only testing where it is truly required.

External scanning of highlighted areas only

The highlighted areas of interest will be excavated and external testing of the main can be obtained from these trial pits (approximate 2 locations per day)
The main will be exposed, any lining material to be removed and then cleaned.
The system is attached to the crown of the pipe and is magnetically anchored to the asset, it then traverses around the asset 360 degrees stopping on its primary position with thousands of wall thickness readings obtained.

The main is then protected with a painted or taped covering prior to its backfill and reinstatement of surface coverings.

Conclusion
NDT Testing programmes are a pro-active approach to pipe failure, however is flawed due to lack of actual asset knowledge.
API offer the removal of guess work during the pipe testing of assets as only the highlighted areas are tested further to determine true pipe condition.
This approach does not only give the client a true understanding of asset condition, but also offers true pro-active approach to eradicate leakage, future catastrophic burst and also in time determines the correct capital spend on the right pipe areas.

API Pipe Testing Philosophy
Look – Undertake live CCTV surveys to determine the most corroded pipelines, check if pipes are lined and solve unknown pipe issues ie buried valves
Listen – Undertake live acoustic inspections to determine areas of leakage interest and identify pinhole leaks
Monitor – NDT testing and ongoing monitoring of high risk pipelines prior to failure