Pipeline Coatings Testing
Ashford, Junction 10A pipeline relocation
In July 2018, Buckleys (UVRAL) Ltd visited a site in Ashford, Kent where a section of pipeline was being relocated. The section of pipe in question is approximately 500 metres in length; running from the south to the north of the M20 motorway, at the proposed Junction 10A.
The gas supplier, SGN distributes natural and green gas to 5.9 million homes and businesses across Scotland and the south of England.
The contractor, Fabricon Pipeline, Mechanical & Civil Engineering contracts to the oil, gas & petrochemical Industries. Specialising in high pressure pipelines, pipeline Diversions, horizontal directional drilling, hot tap applications, AGI construction and civil works.
The drilling company, AMS No-Dig is the largest privately owned Horizontal Directional Drilling and Guided Auger Boring (Trenchless Pipe Installation) contractor in the UK. The inspection company I.A.C.S NDT Limited are a leading, privately owned company that specialise in the provision of Non-Destructive Testing (NDT) examination services.
The radiographers, Spree N.D.T employ a team of inspectors who are qualified to PCN/ASNT/ERS standards and carry out all types of NDT (Non-Destructive Testing).
To test the non-conductive coating for this gas pipeline for porosity, faults and defects using the Buckleys PHD Pro' 1-30kV pinhole detector ― standard/pipeline kit.
METHOD Using a Buckleys PHD Pro’ fitted with a 250mm phosphor bronze brush electrode with 1 extension rod; the pipework’s external coating was inspected at 5kV per mm to SGN/SP/CW/5. The PHD Pro’30kV was earthed using the Trailing earth lead and the sections of pipework was grounded to earth. The operator passed the electrode over the coating of the pipe. Every time the PHD Pro’s alarm system triggered, the area around the electrode was thoroughly inspected and retested to ascertain the exact location of the fault. Faults were subsequently clearly marked for remedial work.
Type of pipe: Gas mains supply Pipe length: 500 meters Pipe diameter: 457mm Coating material: F.B.E (Fusion bonded epoxy coating) Wall thickness: 15.9mm Thickness of coating: 700 microns Voltage: 5kV Test equipment used: PHD Pro' 1-30kV pinhole detector ― standard/pipeline kit.
Porosity, defects and pinholes can be identified in gas pipeline coatings when testing with a PHD Pro' 1-30kV pinhole detector ― standard/pipeline kit using a phosphor bronze brush.
SGN/SP/CW/5 With special thanks to Mr. Peter Dodd, I.A.C.S NDT Limited