Pipelines are widely used throughout the world to transport oil, gas and other fluids over long distances and across continents. They are frequently subjected to extreme climatic conditions and huge temperature variations that can cause serious damage to the outer shell. This is why companies operating these lines use preventive methods to detect clogging or worse, cracks and flaws that can have disastrous consequences.
One of these detection methods is called pipeline ‘pigging’. It uses devices known as ‘pigs’ to perform maintenance operations on a pipeline without stopping the flow of fluid.
Why pigs? Interpretations differ on why these maintenance devices are named pigs. Some allege that pig is an acronym for ‘pipeline inspection gauge’ or ‘pipeline intervention gadget’; others affirm that the original pigs, made of straw wrapped in wire, and used for cleaning, made a noise similar to the squealing of a pig when traveling through the pipe.
As many of these pigs are used in oil or gas pipelines, it is of the utmost importance that they are designed and built in compliance with the very strict requirements enunciated in standards and specifications, most notably in IEC International Standards developed by IEC Technical Committee (TC) 31: Equipment for explosive atmospheres.
As part of its IEC 60079 series of International Standards on explosive atmospheres, TC 31 has developed several International Standards that cover general and testing requirements for several types of pigs, including magnetic or ultrasonic pig signallers, pig tracking systems and pig intelligent systems.
- IEC 60079-0, Explosive atmospheres – Part 0: Equipment – General requirements
- IEC 60079-1, Explosive atmospheres – Part 1: Equipment protection by flameproof enclosures “d”
- IEC 60079-11, Explosive atmospheres – Part 11: Equipment protection by intrinsic safety “i”
- IEC 60079-26, Explosive atmospheres – Part 26: Equipment with Equipment Protection Level (EPL) Ga
…tested and certified by IECEx
As is the case for any product, designing and building pigs in compliance with IEC Standards is not enough. To prove that a pig meets all the requirements spelled out in Standards and can be used in explosive (Ex) areas, it has to go through testing and certification.
This is where IECEx, the IEC System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres, intervenes. An IECEx Certificate is like a passport for manufacturers of Ex equipment. It provides clear proof of claimed compliance with International Standards. It certifies that the equipment in question has the right level of protection. It provides assurance that products bearing an IECEx Certificate conform to the International Standards listed on the same Certificate.
To find out more about the topic and the role of IEC in this area, check out this e-tech article by Claire Marchand.