Single Pig System
The Single Pig System
Demonstration and Overview
A single-pig system is the most common type of pipeline product recovery (pigging) system. Normally the product source is pumped from the source to the destination. The destination can be either a filling machine or another storage vessel for the product.
Single-pig systems usually include a launch station and a return station. In this system the normal position for the Pig is in the pig housing at the launch station.
How a Single Pig System Works
When the line needs to be pigged, product transfer is stopped and the valves in the launch station are changed to allow the pig to be driven to its destination using a suitable propellant. Once there, propellant is introduced at the Receive station to return the valve to the pig housing. The system can be installed to recover product to the filler / destination tank or to send product back to the source tank.