Compensator for the pipeline: types, manufacturers, description and reviews. Compensators for pipelines made of polypropylene
The operation of many devices, communicationnodes and mechanisms imposes high loads on materials and structures used in such systems. Vibration, excessive pressure, and humidity with temperature also have a negative effect. To minimize phenomena contributing to the deformation of materials, technologists provide for the integration of compensators. Especially similar additions are common in heating and water supply systems. In particular, for such needs a compensator is used for the pipeline, which extends the working life of the communication line. There are many variants of the constructions of such elements, but all of them are subject to the same task - reducing loads and harmful effects on the pipes.
Principle of operation
To understand the functions that are performed by thecompensator, it should be said about the natural processes occurring in the pipeline during its operation. The fact is that under the influence of high temperatures the tube lengthens. Conversely, when cooled, it assumes the usual state. If the line has a reliable fixation at two points, then there is a very real risk of mechanical deformation of the material. To prevent this from happening, a compensator for the pipeline is introduced into the structure, which takes on all the loads from the natural deforming processes. We can say that there is a local concentration of elongation and narrowing at specific sites where compensating devices are installed. What happens to this element? Several forces act on it, including transverse and longitudinal forces. In this case, the compensator can flex and take different forms. But in any case it should be a reliable element capable of carrying a responsible service, keeping the tightness of the pipes.
Variation of expansion joints
There are two main classifications of such devices -by design and by materials. In this case, the design can influence the choice of material by the manufacturer. So, today there are the following types of pipe expansion joints, which differ in structural features: bellows, tube, gland and lent. Each of these options provides the performance of functions to reduce deformation, but it has a special device and, as a consequence, recommendations for use. The classification according to the materials is not so wide. At the moment, metal, rubber and polypropylene models are more often used. And now it is possible to consider more in detail the varieties of compensators.
This is the simplest kind of compensator, which alsoare called U-shaped. Its features include the possibility of using the effect of pipe self-compensation. This ability of the line is usually achieved through the special design of communications. So, what does the installation of expansion joints on P-shaped pipelines give in practice? First of all, it should be noted that they can be used even if the level of temperature indicators is high. Thus, the pipe compensator allows to save the structure in the most severe operating conditions and at increased pressure. Part of this is facilitated by the reliable device of the part itself - in the manufacture of the element a curved tube or several fragments of bent taps connected by welding are used. But there are disadvantages to such a variety. In most cases, these are massive components that require an appropriate amount of consumables for production. Accordingly, this is not the cheapest solution to the problem of deformation on pipelines.
In this case, the lens meansA welded construction in which two metal thin-walled components are used. It is thanks to them that harmless deformation compression occurs. As a rule, the lens compensators of pipelines are not used in the singular, but in series. This can be a series of successive elements, each of which takes its compensating load. Inside the element special glasses are provided, by means of which resistance to movement of water can be weakened. To ensure the release of condensate, in the lower parts of such lenses also provide drainage fittings. Such models are effective in the sense that they make it possible to rationally use both the potential of the compensator itself and the pipeline resource due to the selection of the optimum number of elements.
The construction is a combination of twonipples connected to each other. To be more precise, they integrate into each other. In order to increase the sealing function, manufacturers supply devices with packing seals with a packing book. As a result, such a system allows to provide a rather high compensating effect, while possessing small dimensions. However, in technological communications, such models are practically not used because of the complexity of sealing sealing gaskets. It is better to use gland expansion joints for heating pipelines and other communications where there is no presumption of intensive wear of the seal. It is important to remember that damage to the stuffing box will mean a breach of the seal, which is particularly unacceptable in pipelines that carry flammable and toxic media.
Bellows expansion joints
This is one of the most practical and durablecompensators. It is distinguished by its small dimensions, the presence of high quality stainless steel in the structure, and also the device itself, which is designed to receive dynamic and static loads. Also, the advantages of such devices include the lack of stringent requirements for laying, maintenance and installation of special cameras. Regardless of operating conditions, bellows expansion joints can cope with both hydro impact and vibration loads, while maintaining the integrity of communications. By the way, by the service life the devices correspond to the pipes themselves, therefore, premature replacement is not required. The operating range in temperature ranges from 0 to 1000 ° C, which also puts the bellows components in a number of the most cost-effective expansion joints.
Models of this type are made of elastomersand differ in cord reinforcement. Usually rubber expansion joints are used for working in liquid media. Actually, based on the characteristics of the coolant, and should be selected elastomer. For example, the most popular is rubber based on ethylene-propylene or butadiene-nitrile. In the first case, the device is supposed to be used in an aquatic environment, and the second option is intended for working with petroleum products. Not all expansion joints for pipelines are able to work with acids and alkalis. The rubber models intended for aggressive environments are made of a special material called gipalon. To enhance the resistance to chemical attack, manufacturers provide the compensator material and Teflon sputtering. Technologists are also concerned about the structural functionality of rubber products, supplying them with all kinds of connecting rods and corner stops.
Advantages of models from polypropylene
Products of this type are designed for maintenancePlastic pipes, which have many differences from metal analogues. In particular, expansion joints for polypropylene pipelines provide protection against displacement and stretching under the influence of temperature fluctuations and water hammers. Such devices can be used in both cold supply communications and hot water systems. The range of assignment of compensators by type of objects is not limited either. They are installed on the plumbing of administrative buildings, in homes and enterprises.
Although composites and plastics are the mosttechnological materials at the moment, they can not be called unconditional leaders in terms of engineering and operational development. Nevertheless, expansion joints for polypropylene pipelines have many advantages. For example, they are distinguished by a simple device and easy installation. To the undoubted merits of the material itself is a light weight. As a result, the expansion joints ensure the reliability of the pipeline operation without disruption and deformation.
In the domestic market is mainly representedproduction of Russian enterprises, which is distinguished by an affordable price and relatively good working qualities. For example, the company "Armatek" specializes in rubber vibrovstavkah - these are expansion joints, which differ in their small size and versatility in the gasket. Quite a lot of manufacturers are actively developing the segment of bellows models. Compensators of this type with good quality are produced by Compens and Metalcomp. If the compensator for the pipeline needs to be supplemented with other fittings and, in particular, with metal hoses, then it is worthwhile to turn to the assortment of the Vladimir plant "VZR". Of course, the domestic producer is not able to fully cover the entire demand. Especially in advanced developments and technical innovations, Russian enterprises lag behind foreign colleagues. In this regard, it is worth noting the company "Apel" and "ANT", which not only produce, but also supply high-quality compensators of famous brands from Europe.
Mounting of expansion joints
It is desirable to perform device mounting,beginning with the drawing up of a pipeline diagram. It marks the points where the compensators will be located. For the correct determination of these areas, two main factors must be taken into account - temperature changes throughout the entire length of the line, as well as remoteness from the pipe attachment points. Usually, the elements are installed in the middle between two fixing points. Directly the installation of pipe expansion joints is usually realized by welding. To simplify this operation, the device is removed and the fixing cage is moved. A special mounting device is attached to the free end of the compensator and the prepared pipeline section, by means of which the device is stretched to the junction with the pipe. After this, the joint is brewed and the adaptation for the installation is removed from the compensator.
Feedback about compensators
The content of additional reinforcement causesthe need for additional costs. This factor forces many service organizations to pre-calculate the communication network with the possibility of self-compensation. And yet, users who decide to install a special compensator for the pipeline, feedback on its benefits are mostly positive. Today, one can not fully appreciate its effect, since practically all pipelines are supplied with such devices. But there are also critical opinions. They are usually associated with the need for calculations, errors in which often lead to accidents. In terms of the longevity of the compensators, too, everything is not smooth. Many recommend not to save and immediately acquire strong and efficient bellows models.