Pipe Pig is pushed by gas, liquid, or pipeline conveying medium. And it is a special tool for cleaning pipes. Pipe Pig can carry a radio transmitter and ground tracking instrument. They may together constitute an electronic tracking system. Therefore, this product is a very practical device. So if you want to know more about Pipe Pig please contact our professionals to answer them for you.
Purpose of Pipe Pig:
The transmission efficiency and service life of gas transmission pipelines are very important. They largely depend on the cleanliness of the inner wall and interior of the pipeline. Substances are harmful to gas quality and pipeline. Such as condensate, water, sulfur, mechanical impurities, etc. After they enter the gas transmission pipeline, they will cause corrosion of the inner wall of the pipeline and increase the roughness of the pipe wall. The accumulation of a large amount of water and corrosion products will also locally block and reduce the flow section of the pipeline. During the construction process, the atmospheric environment will also rust the uncoated pipeline.
It is inevitable that some welding slag, soil, stones, and other harmful objects will be left in the pipeline. After the pressure test of the pipeline water, it is difficult to drain all the water simply by using the opening of the pipeline height difference. To solve the above problems. Therefore, it is very necessary for us to clean the inside and inner walls of the pipeline. Therefore, the pigging process has always been an important process measure for pipeline construction and production management.
The purpose of Pipe Pig can be summarized in the following four aspects:
(1) Remove the accumulated liquid and sundries (dust) in the pipe. Reducing friction loss. Thereby improving the conveying efficiency of the pipeline.
(2) Avoid ponding in low-lying areas. (the back-and-forth fluctuation of water not only accelerates electrochemical corrosion due to the presence of electrolyte but also produces mechanical scouring, which makes the pipe wall thinner and causes corrosion cracking);
(3) Remove the deposits and corrosion products from the pipe wall. Which makes it free of additional corrosion electrodes. Reduce corrosion under scale;
(4) Many new applications such as in pipe inspection.
Many new applications
① Sizing. It cooperates with the pig detection and positioning instrument. We find out that the pipe diameter deviation larger than the design, construction, or production regulations;
② Diameter measurement, thickness measurement, and leakage detection. It is integrated with measuring instruments or serves as a traction tool for these instruments. They detect and record the condition of the pipeline through the inside of the pipeline;
③ Filling and conveying pressure test water: when filling the pipeline with pressure test water. To avoid leaving bubbles at the high point of the pipeline. Affecting the stability of the test pressure. It sends a pig in front of the water column to remove the air in the pipe;
④ Separate the medium in the pipe. Replace the air and pressure test water in the pipe with natural gas. Or replace the natural gas in the pipe with air. We use a pig to separate the two media. As this prevents the formation of explosive mixtures. The emission loss of combustible gas can be reduced. Improve work efficiency;
⑤ Apply corrosion inhibitor and an epoxy resin coating on the inner wall of the pipeline. The liquid corrosion inhibitor can be pushed by one pig or entrained by two pigs. We painted the inner wall of the pipeline during the operation along the line. The internal coating construction of epoxy resin is relatively complex. Including cleaning of the inner wall of the pipeline, chemical treatment, epoxy resin coating, control and inspection of coating quality, etc. These processes are all realized by special pigs.
Cycle: According to the conveying medium of the pipeline, the conveying efficiency and pressure difference of the pipeline shall be considered. We can determine a reasonable pigging cycle
Classification of Pipe Pig
1. Fully coated polyurethane foam pig
The main material of the fully coated polyurethane foam pig is polyurethane. Its surface is coated with polyurethane wear-resistant leather. Because this can improve wear resistance. The inner core is polyurethane foam. The interference is usually 25mm. The running distance can reach 200km.
Features: it can mainly find out the basic situation inside the pipeline. The deformable margin is large. Good passing performance. It can break by itself under the condition of high-pressure difference. So the security is high. Therefore, it is less likely to affect the normal operation of the pipeline.
2. Rubber pig ball
The rubber pig ball is a hollow ball whose outer diameter is 2% larger than the inner diameter of the pipeline. Its main material is neoprene. We need to inject water into the ball when we use it. This is to exhaust the air in the ball. When the pig ball is pressurized and expanded by water, the interference of the ball is 3% – 10%. The rubber pig ball forms a tight ball plug with a certain hardness in the pipeline. Because this can push out the sewage and dirt in the pipe.
Features: the pipeline is installed in mountainous areas with large topographic relief and elevation differences. It can also clean 90% of the sewage is in the pipe. Rubber pig balls are soft spheres with large deformation. It has good passing performance. It mainly removes the liquid and separation medium in the pipeline. The pig ball has a poor ability to remove blockages. And it is easy to be lifted and rolled by hard objects in the pipe. Stones, sticks and other sundries left in the pipeline during pipeline construction can only be pushed out after multiple pigging. For iron sulfide powder close to the inner wall of the pipe. The cleaning effect of rubber pig balls is not very good.
3. Cup pig
The cup pig has a rigid framework. It is composed of two or more leather cups at the front and rear. When it runs in the tube, it maintains a fixed direction. It can carry various detection instruments and devices. The cup shape of pig is an important factor to determine the performance of pig. The shape of the cup must adapt to the use of various pigs. The cup pig includes rubber cup, pressure plate and flange.
It is also composed of a guide and a transmitter shield. It is sealed by making use of the 1% – 4% interference of the edge skirt of the leather cup with the pipe wall. The pig is pushed forward by the natural gas pressure difference between its front and rear. The cup pig has good sealing performance. It can not only push out the accumulated liquid in the pipeline. Moreover, it can push out solid impurities far better than pig balls.
4. Dish cup straight plate pig + caliper aluminum plate
The utility model comprises a a support plate, a dish-shaped leather cup, a caliper plate, a spacer and a skeleton. Features: good sealing performance, strong passing capacity and long running distance. It can remove the dirt such as accumulated liquid and dust in the pipeline. After passing the ball, we can observe the deformation of the caliper aluminum plate on the pig. Because this can judge the defects and deformation of the pipeline. Inspect the passing performance of the pipeline.
5. The two-way straight plate mechanical Pipe Pig
It includes a guide plate, a straight plate sealing cup, a spacer and a skeleton
Features: light structure. Strong passing ability. Good pigging effect. It can effectively remove the suspended dirt in the pipeline. Compared with butterfly pig, straight plate pig has better cleaning effect. However, in operation, the straight cup wears faster and the running distance is shorter.
6. Two-way straight plate pig + diameter measuring aluminum plate (90% inner diameter)
The utility model comprises a guide disk, a straight plate sealing cup, a spacer, a caliper plate and a skeleton
Features: light structure. Strong passing ability. It can effectively remove the suspended dirt in the pipeline. After passing the ball, we measure the deformation of the aluminum plate according to the diameter installed on the pig. We judge the defects and deformation of the pipeline. Inspect the passing performance of the pipeline.
7. Pressure control cup pig
The pressure-controlled pig is to install pressure rupture discs on the mechanical cup pig. When the pig goes out during operation
. The differential pressure before and after the pig rises to 0.7-0.8mpa. Then the bursting disc will automatically open to release the pig. Because this can realize gas transmission in the stuck state of the pig. We can preliminarily judge the pipeline capacity. This can achieve fixed-point tracking on the ground by installing a transmitter.
8. Straight plate nylon brush pig
The utility model comprises a straight plate, a nylon brush, a spacer, and a skeleton.
Features: strong passing ability. High pigging efficiency. Clean up fine impurities more thoroughly. It can remove the hard dirt attached to the inner wall of the pipeline.
9. Two-way straight plate magnet pig
It comprises a straight plate, a magnet, a spacer, and a skeleton.
Features: it can remove ferrous dirt and small particles in the pipeline. This can reduce the interference of ferromagnetic impurities to the detector. And this can improve the internal detection data quality.
10. All polyurethane soft Pipe Pig
It mainly includes cups, skeletons, and connectors. It is all made of polyurethane. And it may carry a radio transmitter. It does not require maintenance. Good sealing. Good wear resistance. High strength. Strong passing ability. The deformation is large. It is not easy to jam. Strong adaptability to elbows. Good cleaning effect. It has many advantages. Pipe Pig is mainly also used in complex natural situations. It can clean and descale irregular long-distance pipelines.