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NoPig Metal-Loss Detection System for Non-Piggable Pipelines

Overview

Fast Facts

Project No. 122
Contract No. DTRS56-03-T-0006
Research Award Recipient FINO AG, Hildersheil Germany FINO AG, Hildersheil Germany ,
AOTR Joseph Mataich
Researcher Contact Info Matthias Heldt N.P. Inspection Services GmbH Am Flugplatz 13, 31137 Hildesheim, Germany Tel.: +49 (0) 5121 28126-22 Fax: +49 (0) 5121 28126-66 Email: m.heldt@npinspect.com

Technology and Commercialization

Technology Demonstrated Yes
Commercialized (in whole/part) Yes
Commercial Partner EMPIT - Electromagnetic Pipeline Testing GmbH http://www.empit.com/
Net Improvement The sponsored research resulted in the NoPig inspection technique, a new above ground technology which can be used on metallic pipelines in a wide range of diameters while remaining truly non-destructive not affecting normal pipeline operations. EMPIT purchased the technology in 2015 and now offers it as AGIT (Above Ground Inspection Technology) which utilizes a non-destructive testing method for unpiggable pipelines which uses above ground measurements for detecting wall thickness anomalies like corrosion. The method uses an applied current between two points on a pipeline up to 1 km apart. The inspection current contains several harmonic components at distinct frequencies. The resultant magnetic field is measured above ground along the pipe. The measurement data are processed to determine the magnetic field shape. In case of a local pipe wall thinning a frequency-dependent deviation of the magnetic field shape from the circular form occurs. The skin effect and the magnetic stray flux evoke this deviation in case of wall defects caused by corrosion.

Financial and Status Data

Project Status Closed
Start Fiscal Year 2003 (06/15/2003)
End Fiscal Year 2005 (12/31/2004)
PHMSA $$ Budgeted $387,818.00

Main Objective

The NoPig Pipeline Inspection System has been developed for detecting metal loss anomalies on small diameter non-piggable pipelines from above ground.

Public Abstract

The NoPig Pipeline Inspection System has been developed for detecting metal loss anomalies on small diameter non-piggable pipelines from above ground. Contact points at two places no farther than 500 meters from each other are needed. The technology makes use of the skin effect. It utilizes a difference between magnetic fields at low and high frequency produced by electric currents passed through the pipe under test. The low frequency current will distribute itself and travel throughout the entire cross section of the pipe. The high frequency current will travel along the outer surface of the pipe (Skin effect). Both currents generate a magnetic field which shape is dependent on the presence of a defect.

This dependence is discovered due to use of different frequencies. The difference in the magnetic field shapes at different frequencies are caused by e.g. internal or external corrosion, and possibly gouges, and cracking. The System has achieved success in reliably detecting immediate response defects on 3" to 12" diameter pipes. More accurate sizing of these defects from the information gained from these inspections would lead to an improved external and internal pipeline-monitoring device for pipelines that can not be inspected by current in-line technology. The instrument and software development and improved practice in applications of the system will lead to improved detection capabilities for scheduled response defects. The NoPig technology can be applied to larger diameter pipelines but requires advanced system and software development and extensive practical application to identify pipeline anomalies and to discriminate defects. Objectives:

  • Confirm the NoPig System provides accurate pipeline metal-loss detection within present specifications.
  • Improve the system to be able to discriminate between defects.
  • Apply the technology to larger diameter pipelines for metal-loss detection and discrimination

Relevant Files & Links

Final Report

Technical Reports and Documents

A report describing the NoPig Inspection Technology

NoPig_Final_Report_09202_October-02.pdf