A key part of Pipeline Maintenance Program is a procedure called in-line inspection, also referred to as pigging. One of the most effective ways to do this is with pipeline inspection guages, or pigs to perform the operations on the pipeline without interrupting flow and the launchers/receivers also known as scraper traps that facilitate the process.

Once introduced into the pipeline via the pig trap, the launcher is closed and the pig is forced through the pipeline by pressure of the product flow until it reaches the receiver, or pig trap. As the pig moves through the pipeline it effectively cleans and clears plugs by sweeping the sides and pushing plugs and debris ahead where it can be cleared at the trap.

The procedure is also used to locate flaws, cracks and areas where corrosion may have occurred on the pipeline.  Pig Launchers and Receivers are used in daily pipeline operations as well as construction. The type of pig used is determined by several factors including, the type of procedure to be performed, the size, application and operating conditions and layout of the pipeline:

• Utility Pig - Cleaning debris after construction or clearing plugs to increase pipeline efficiency

• Inspection Pig - Inspection for cracks, flaws, ID measurement, pitting and other corrosion problems

• Gel pigs - Liquid chemical pigging system

• Sealing Pig - To separate products in the pipeline and for De-watering  pipelines after hydrostatic testing

• Specialty pigs - used to stop, plug and isolate sections of pipeline during pipeline maintenance

To launch and receive pigs or spheres special piping is required at the inlet and exit of the pipeline to be pigged. A Launch/Receive system for pigs consists of the following components: launch and receive piping/barrel; quick opening closure; valves; pressure gauges; bypass tees; skid assembly with drip pan; handling equipment for pig.

EN-FAB designs  and manufactures skidded launcher and receiver packages with manual or automated launching systems for a wide variety of on and offshore applications. Over 35 years of experience in the design and manufacture of launchers and receivers make EN-FAB your obvious choice for this critical equipment.