Batching and Chemical Dosing

Batching is the process of moving different products through the same pipeline which is much more economical than to lay dedicated pipelines.

Batching, swabbing and separation are similar terms used depending on the application.

Swabbing is the term often used when removing Natural gas Liquids (NPL) from NG product lines.

Product separation Pigs can be used between product batches to preventing mixing through the pipeline. Eg Crude oil pipelines running different batches of crude oil which may have different sources, destinations or require different refining processes.

Pig trains is essentially a series of batching pigs separating one product from another; often air is separated from a volatile product or maybe water ahead of a drying train of methanol and nitrogen. Similarly batching chemical cleaning processes of underground pipelines often is an approach to save on excess chemical use.

In hydrostatic testing, batch pigging methods is adopted for removal of air ahead of the testing water and in the final stages, to remove the water before drying of the pipeline.

Plants such as food, dairy, wine, paints and pharmaceuticals use batching pigs to remove product from the pipeline prior to CIP cleaning or assist in the separating of different products in common pipelines