THE DIFFERENT PIGS AND THEIR USE
These are comprised of a polyurethane foam cylinder possibly with a polyurethane coating.
Low density foam pistons: used for wiping pipelines after draining.
Medium or high density foam pistons with coated bottom: used for water filling or draining short pipelines.
High density foam pistons with coated bottom and crisscrossed body: same use as above for longer pipelines.
High density foam pistons with coated bottom and crisscrossed body equipped with metal hairs: used for cleaning pipelines, and dusting gas pipes.
Gel pigs are cylinders of gel that are made in situ just before their insertion into a pipeline.
They are generally used for draining pipelines that are badly distorted or that have severe restrictions.
- used for:
- separating products in oil pipes,
- filling pipelines for water tests,
- draining pipelines after tests.
- used for:
- periodic scraping of oil pipes (crude oil transportation),
- scraping of operational pipelines conveying products liable to create deposits,
- cleaning of encrusted or even partially obstructed pipelines,
- removal of internal coatings.