In-line PIGs with movable collars are designed to work in gas pipelines with relatively low pressure and low gas consumption (distribution network and gas outlets).

The movement of in-line PIGs in such gas pipelines is characterized by jerks and stops, which impair the quality of inspections and cleaning. A pig with movable cuffs solves the problem of uneven movement.

Polyurethane cuffs perform swinging synchronous movements, due to which the pig "squeezes" through various bore in the pipeline (taps, valves, irregularities from poor-quality pipe welding, etc.) without accumulating pressure drop and subsequent jerks.

An internal motor is used to drive the cuffs, which works flawlessly in any environment due to a small pressure drop.

The pig with movable cuffs is used as a head (pulling) section of an inspection pig or as a universal cleaning pig.

Solving the problem of uneven movement

The way the device moves in the pipeline due to the oscillatory movement of supporting elements such as polyurethane discs or cuffs is patented.

An in-line cleaning device or a towing section of an inspection tool is designed to pass typical obstacles in pipelines:

• Tapering to 70% of the outside diameter of the pipeline;
• Sharp bends in pipelines with a radius of 1.5 Du 90 degrees (according to GOST 17375-2001);
• Equal tees with a bottom outlet;
• Inserts protruding (plungers);
• Wedge and gate valves.

A low-frequency electromagnetic PNT transmitter is located inside the PIG of the pig, combined with the rotor of the engine, which sets the bearing cuffs in rocking motion.

The transmitter allows a low-frequency receiver to track the position of the pig as it moves inside the buried pipeline.

The result of many years of research and development

At present, the technology has been developed and an installation has been created for the manufacture of the rotor and stator of the engine, as well as a mechanical system for converting the movement of the rotor into the rocking movement of the cuffs. This technology makes it possible to create inexpensive pigs with movable collars for any pipe diameter.

A prototype was assembled and successfully tested for a pipeline with a diameter of 150 mm (6 inches). The tests were carried out in a hydrostand with transparent walls. The results of these tests are posted on You Tube .

The PIGs are supplied according to the agreed technical specifications for various pipe diameters from 150 to 1420 mm.

Additional features

The principle of movement of the inline PIG due to the swinging movement of the bearing elements can be applied not only for the needs of inspections or cleaning of gas pipelines.

For example, it is possible to create a device that will move at a given speed even against the flow of the pumped liquid or gas.

Based on proven solutions for electronics, mechanics and hydraulics, as well as on new developments, our company is able to design, manufacture and test a custom product for specific customer needs.