Pigging

A pig (English pig - pipeline inspection gauge) is a cleaning or inspection device for use in pipelines. Other tasks can be or depending on the consistency of the product support the transport itself in the rule should not be interrupted for the operation of the clean separation between successive batches. This technique is used in the gas, petroleum products and pipeline technique.

The pig fills the pipe cross-section and migrates either simply with the product flow through the line (usually oil), or must be due to extra pressure applied (water or air ) are pressed through the line. As part of the pig technology in addition to the pig still in the system built-in locks are ( technically known as " pig - trap" ) is required by the pig are used in the lines and occupied by back printing, but also, after completion of the proposed test section, can be removed. There are two fundamentally different applications.

As faucets can be used that can completely open the cable cross-section, such as ball valves and gate valves in piggable pipelines only ones.

Applications

Newts

Pigging a funding procedure ( called pigging in the jargon ), highly viscous liquids, pasty media, also powders and granules are almost completely removed from piping systems with the (usually valuable ). This is an approximately spherical, tapered in the middle object, just the pig, pressed with water or compressed air through the conduit system. He then pushes the ineffable medium before it.

Service tasks

For larger diameter pipes, particularly for gas or oil, there are a variety of service functions for pigs. They consist of a round, the cable cross-section roughly ( or by rubber sleeves complete) sealing plate at both ends and a thinner midsection. The pig is so fitted, so that it moves easily through the arches in a line. The following versions are only examples:

• With attached brush wreaths they are used for cleaning.
• In rare cases, with simple separation pigs very different (oil) separated batches in pipelines that are consecutively sent directly by the management and should be mixed as little as possible.
• Others bring with complex measuring technology and provide real robot; they can, for example, by ultrasonic or eddy current probes ( then with Ranger probes for eddy current testing ), the wall thickness and thus measure the corrosion state of the line. Also using ultrasonic or eddy current can be traced tension cracks; one then speaks of Rissprüfmolchen. Meanwhile, there are ultrasonic pigs, the wall thickness and cracks can be measured simultaneously. Since these must carry a larger amount of probes and a lot of electronics and power supply, they are built very much longer, sometimes coupled together in kind of a train of several units. When the power supply there are two alternatives, either carry large and heavy batteries or to draw the energy from the movement by pressing wheel and dynamo. However, the latter is very uncertain especially in crude oil because of its slipperiness and the slip of the Dynamorads. So that one displays found on the measurement can also be accurately assign places in the line, are placed on the outside line at a certain distance pig station that detects another sensor on the pig. In a validation through a set of data from several hundred gigabytes to be backed up to flash memory in order to then be read by a suitable data interface ( FireWire or Ethernet) is created.