PIG Launchers, PIG Receivers and PIG Traps
Pipelines play a major role in the gas and oil industry. In fact, pipelines are the most used method for transporting natural gas, crude oil and refined products. Pipelines require routine maintenance, inspection, cleaning, clearing and PIGS are used to perform these various tasks.
What exactly are PIGs?
PIGs are devices inserted into the pipeline that have a slightly larger bore than the pipe it’s inserted into. This allows the pipe surface to be scraped as it moves through the pipe.
You can find many different types of PIGs from foam, used for batching and product removal, to solid cast, used where better sealing capabilities are needed. There are also Smart PIGS used to record information about the internal condition of pipelines. The Smart PIGS can measure restrictions in the pipe as well as metal loss.
What are PIG Launchers / PIG Receivers / PIG Traps?
A pig launcher is a system used to send a PIG through a pipeline. It uses pressure to propel the PIG out of the launcher barrel and sends it through the pipeline system. These come in a variety of sizes depending on the pipeline size. Components typically include a closure door, main line valve, kicker line valve, bleed valve, pressure gauge, drain valve, and PIG signal. The PIG signals are used on the launchers and receivers as well as various places along the pipeline. This helps the company track where in the pipeline their PIGs are located. The pig receiver is set up on the other end of the pipeline section to receive the PIG. Materials can include carbon steel, stainless steel, and even FRP.
PIG launchers are located where a PIG is to be sent into the pipeline. Likewise, PIG receivers are placed where the PIG is to be removed from the pipeline. You will find launchers and receivers all along a pipeline. It is important to depressurize the pig launcher and receiver tubes before inserting or removing the PIG to ensure safe operation.
How Often Are Pipelines Pigged?
The frequency is set by the pipeline owner and depends on the product. A gas pipeline may rarely be pigged until the pipe integrity needs to be checked. A crude oil pipeline could require pigging daily if the oil has wax, sand and other debris.
Why Should You PIG your Pipeline?
Pigging is an essential part of keeping your pipeline at peak performance and ensure pipe integrity. PIGs can also clear out the entire line contents with each product transfer. Doing so will save costly downtime, and ensure you’re maximizing your ROI.