What is "pigging"

Pig \Pig\, v. t. & i. [imp. & p. p. Pigged; p. pr. & vb. n. Pigging.]

1. To bring forth (pigs); to bring forth in the manner of pigs; to farrow.

2. To huddle or lie together like pigs, in one bed.

1. damned (''used as a mild intensive''). n. The action of the verb ''to pig''. v

2. (present participle of pig English)

1. n. domestic swine [syn: hog, grunter, squealer, Sus scrofa]

2. a coarse obnoxious person [syn: slob, sloven, slovenly person]

3. a person regarded as greedy and pig-like [syn: hog]

4. uncomplimentary terms for a policeman [syn: bull, cop, copper, fuzz]

5. mold consisting of a bed of sand in which pig iron is cast [syn: pig bed]

6. a crude block of metal (lead or iron) poured from a smelting furnace

7. [also: pigging, pigged]

1. v. live like a pig, in squalor [syn: pig it]

2. eat greedily; "he devoured three sandwiches" [syn: devour, guttle, raven]

3. give birth; "sows farrow" [syn: farrow]

4. [also: pigging, pigged]

See pig

Pigging in the context of pipelines refers to the practice of using devices known as "pigs" to perform various maintenance operations. This is done without stopping the flow of the product in the pipeline.

These operations include but are not limited to cleaning and inspecting the pipeline. This is accomplished by inserting the pig into a 'pig launcher' (or 'launching station') - an oversized section in the pipeline, reducing to the normal diameter. The launcher / launching station is then closed and the pressure-driven flow of the product in the pipeline is used to push it along down the pipe until it reaches the receiving trap – the 'pig catcher' (or 'receiving station').