3 a person regarded as greedy and pig-like [syn: hog]
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
1 live like a pig, in squalor [syn: pig it]
- Rhymes: -ɪɡɪŋ
- The action of the verb to pig.
- present participle of pig
Modern pigging systems are highly sophisticated sets of equipment that consist of a standard 5-6 finned pig with an intelligent transmitter that has a global positioning system fixed on it to tell the exact location of the pig inside the pipeline while it is on the move. Along with the GPS positioner there are a host of other instruments like the internal camera that takes live video of the pipe condition inside while the pig is moving, the thickness gauge that constantly measures the thickness of the wall of the pipe as the pig moves.
As the pig moves inside the pipe data like the speed of the pig, flow, rate of fluid inside etc is measured at regular intervals. So by the time the pigging process is over the complete set of data for all the measurable parameters is ready outside.
This data is compiled and used for post pigging analysis about the condition of the pipeline from inside.
For GPS positioning, the pig has a transmitter that sends a signal outside the pipe where a recorder (above ground marker) records the time the pig passes by that precise location. The pig actually has a gyro on it that records angles and combines that with distances and when combining all 3 data sets the GPS positioning can determined. It is difficult for a GPS receiver to be located on a pig since it may be several feet below ground and/or surrounded by steel.
pigging in German: Molchtechnik