Pigging procedure pdf

Specialty of others can be an excellent degree of assistance and knowledge. A pigging system works by propelling the pig through the pipe with either a gas or liquid. Gas propulsion is normally accomplished by using either compressed air or nitrogen.

For liquid propulsion, the pig is normally pushed with either another product or the flush media commonly used by the client. That means during pigging procedure the valve No1.

If the pig has passed through the pipeline the snubber stops it. The choice of these pig traps will depend on the type of pig to be run and pipeline design conditions. Pipeline pigging has a significant role to play in meeting these conditions, and pigs are met with in a number of guises during pre-commissioning operations. This paper is intended to provide an overview of the uses of pigs in these operations, and provide some basic information on train design and pig selection.

The pig is inserted into the pig launcher which is slightly larger in diameter than the pipeline. The launcher is then closed and the force of fluid moving through the line propels it along the entire length of the pipe,. Procedures for pigging operations.

Pipeline pigs are capsule shaped objects which travel through the pipeline, cleaning the inner walls of the pipeline by brushing action. During a pigging pipeline procedure , a launcher is used upstream, and a receiver downstream. Sphere launchers are generally designed for multiple launching and recovery duties, featuring longer barrels that allow operators to load several spheres into the magazines for automatic launch.

Senior operations staff typically supervise pig launching and receiving procedures , as safety procedures must be adhered to at all times, and they may have to facilitate a variety of troubleshooting efforts. A foam pig or pigs is normally sent ahead of the water when filling the test section to prevent mixing the test water with air in the line. Internallycoated pipelines are often flushed with water ahead of a pig to prevent debris from being dragged along the inside surface, damaging the coating. The purpose of operational pigging is to obtain and maintain efficiency of the pipeline to be pigged. Calculations of time, required pressure and flow for pigging and a typical pig position calculation in a format to be agreed upon with the Company.

Testing procedures for all main equipment and instruments. The following procedure to be described is a general guide to pipeline pigging as they vary depending on the pipeline setup as well as the operation procedures. In some cases or companies, the pig launcher might be left on stream and in some, it is isolated after the pig has been run.

Any pigging operation should be carefully planned to ensure that the correct tool is use that appropriate pipeline cleaning is carried out, the pig will not get stuck, contingency measures are in place to locate and remove a stuck pig, and that safe procedures for pig launch, receive, and handling are followed. The process of conducting internal pipeline inspection and cleaning by running pigs is a hazardous procedure field personnel are required to perform. Step Description Inert gas (Nitrogen) is injected into the pig launcher after confirmation of closing the isolation valve of the pig launcher to remove any residual town gas inside the pig launcher.

Pigging operation refers to maintenance practice for pipelines using pipeline pigs, for cleaning or. As with many procedures on a pipeline, any steps that can be carried out before the pipeline is sealed will usually be easier than working with a closed system.

A clean pipeline is required before a successful survey can be accomplished using either a gauging pig or an instrumented pig to ensure that the pipe has been laid properly. A form of flow assurance for oil and gas pipelines and flowlines, pipeline pigging ensures the line is running smoothly. In the context of pipelines pigging refers to: The practice of using devices known as pigs to perform various maintenance operations on a pipeline.

Open Valve D to vent launching trap to atmospheric pressure. When the trap is completely drain (psig) with Valves D still open, open the closure door and insert the pig so the first cup forms a tight fit in the reducer (point X) 4. Pigging systems are used to insert a pipeline inspection gauge ( pig ) into a live system transporting gas or liquid media, in order to perform various maintenance operations. As they involve such high pressure levels, pigging operations should follow a precise procedure to avoid disastrous outcomes. Mechanical interlocks safeguard normal pigging procedure conditions During a routine pigging. The line consists of a temporary 20” multi- pig launcher.

This has the capacity to hold pigs for each pigging task (flooding and dewatering). The 20” pipeline begins at a water depth of 130m, falling to a maximum depth of 350m, with a temporary receiving head at 73. The water depth at the receiver is 250m complete with a non-return valve. Pigging Solutions Extend Life of Pipelines, Optimize Product Flow Pigging is a vital component of ongoing pipeline maintenance and operation, but its value extends far beyond those roles.

Pipeline owners and operators also use pigs to protect their product purity, remove unwanted materials and items from their line, prepare for pre-commissioning and inspection testing, and confirm pipeline defects.