Intelligent Pig


Intelligent Pigs

A Pipeline inspection gauge or pig in the pipeline industry is a tool that is sent down a pipeline and propelled by the pressure of the product in the pipeline itself. It is the chief device used in pigging.

There are four main uses for pigs:

  1. physical separation between different liquids being transported in pipelines;
  2. internal cleaning of pipelines;
  3. inspection of the condition of pipeline walls (also known as an Inline Inspection (ILI) tool);
  4. capturing and recording geometric information relating to pipelines (e.g. size, position).

The original pigs were made from straw wrapped in wire used for cleaning. They made a squealing noise while traveling down the pipe that sounded to some like a pig squealing; the term "pipeline inspection gauge" was later created as a backronym.

One kind of pig is a soft, bullet shaped polyurethane plug that is forced through pipelines to separate products to reduce mixing. There are several types of pigs for cleaning. Some have tungsten studs or abrasive wire mesh on the outside to cut rust, scale, or paraffin deposits off the inside of the pipe; others are plain plastic covered polyurethane
Inline inspection pigs use various methods for inspecting the condition of a pipeline. A sizing pig uses one (or more) notched round metal plates that are used as gauges. The notches allow different parts of the plate to bend when a bore restriction is encountered. More complex systems exist for inspecting various aspects of the pipeline. Intelligent pigs, also called smart pigs, are used to inspect the pipeline with various sensors and record the data for later analysis. These pigs use technologies such as Magnetic flux leakage (MFL) and ultrasonics to detect the various aspects of the pipeline. Intelligent pigs may also use calipers to measure the inside geometry of the pipeline.


Link: Inline Inspection Association

Research Publication:
Khayamim S. and Samavatian S., Different inline inspection methods for Oil and Gas Pipelines, B.Sc. Thesis, K.N. Toosi U. of  Tech. 2003.
Performance Movies:
Pipeline Construction (9.1 M)
Cleaning Pig (8M)
Profile Pig (9M)
Odometer Pig (8.2M)
Magnetic Flux Leakage (MFL) (17M)
Ultrasonic Testing (UT) (16M)
Pipeline Defects (2.6M)
Pipeline Repair (6.5M)

Copyright Advanced Robotics & Automated Systems

K.N. Toosi University of Technology

P.O. Box 16315-1355, Tehran, IRAN,

Last Updated December 11, 2010