Pvc pipes and their features

Among the variety of pipes, a worthy place is occupied by products from polyvinyl chloride, the scope of which is very extensive. Like any other pipe products, PVC pipes are made according to GOST, and, for each type, there is a regulatory document. Next, we consider the main characteristics and properties of PVC pipes, according to these state standards.

General information

So, PVC is a type of plastic, which is characterized by the following properties:

Due to these properties, PVC pipe has found wide application both in everyday life and in industrial production. In particular, of these products collect reliable non-pressure highways, which have excellent throughput and low weight.

Specifications

The technical characteristics of these pipe products are based on the physical properties of polyvinyl chloride.

In particular, this material gives the product the following positive qualities:

• Good ring stiffness, so that the PVC pipe can withstand an internal pressure of 120 atmospheres.
• Resistance to temperature distortions (at permissible operating temperature). The increase in size during heating is only 5 percent, which is significantly less than, for example, the polypropylene analogue.
• Good UV resistance.
• Insignificant weight of PVC pipe.
• Environmental friendliness, so that PVC communications can be used to transport drinking water.
• Smooth surface, what matters to sewer systems as it reduces the likelihood of silting.
• Chemical Resistance.
• Low price.

Of course, along with the advantages, there are some drawbacks that are also associated with the above properties of polyvinyl chloride.

These include:

• Poor heat resistance, as a result of which the products cannot be used for hot water supply and heating systems.
• The need to warm the system, where it can be exposed to low temperatures.

Note! The working temperature in the pipeline should not exceed 40 degrees Celsius.

Kinds

Classify the products in question can be primarily for their intended purpose.

They may be intended for:

• Free-flow systems;
• Pressure systems.

Next, take a look at the features of each of their species.

Free-flow

Non-pressure pipes, as a rule, are used in sewage internal and external systems. Their installation is carried out bell-shaped by means of sealing rings. Thanks to this, even a non-specialist can assemble the pipeline with his own hands.

PVC pipe sizes for non-pressure sewer systems can be as follows:

• Diameter - from 63 to 315 millimeters.
• Length - from 0.5 to 6 meters.

Note! The weight of 1 m PVC pipe, depending on the diameter, is from 1 to 9.54 kg.

I must say that the GOST for PVC pipes of this type contains 13 sizes. The maximum working pressure in such systems varies within the range of 0.5–0.63 MPa, however, their walls can withstand a pressure of 10–20 MPa.

Corrugated products can also be referred to non-pressure pipes. Corrugation - PVC pipe is extremely flexible, therefore it is used as a connecting element, for example, to connect plumbing fixtures to the sewage system.

Pressure head

The main requirement for pressure pipelines is the ability to withstand high internal pressure. Therefore, the connection is carried out by the adhesive method, although the external products resemble the above described free-flow analogs, since there is also a socket at their end.

The diameter of these pipe products can be from 10 to 90 mm. Moreover, the corresponding GOST has 11 of their original sizes.

The working pressure in such systems can reach 2 MPa. A larger value cannot connect.

I must say that in addition to the bell-shaped ring and adhesive products, there is also a smooth PVC pipe, which is used when installing the pipeline on adhesive and threaded pipe fittings. Its diameter can be from 10 to 315 millimeters. They can be used both in pressure and free-flow systems.

CPVC

Speaking of PVC pipe products, it is impossible not to mention CPVC pipes, which are obtained from chlorinated polyvinyl chloride. This material was created in the laboratories of NASA in the last century, however, it was not used immediately for domestic use, as the production technology was kept secret for a long time.

The technical characteristics of the CPVC pipe are higher than those of ordinary PVC. In particular, it has a higher tensile strength - 70-80 MPa, which is 700-750 atmospheres, as well as a relatively high melting point - 480 degrees Celsius.

Most often, these products are used for the following purposes:

• For industrial water pipes, working under high pressure.
• For automatic fire extinguishing systems.
• In gas pipelines.
• In the food industry. Since such a pipeline does not interact with the transported liquid, it is often used for pumping juices, milk, beer, and other products.
• Due to its resistance to high temperatures, CPVC can be used in hot water pipelines and in heating systems.

Thus, the products of their chlorinated PVC are also widely used.

Installation Features

Assembly of the pipeline, as already mentioned above, can be done in several ways:

• With the help of sockets;
• By cold welding;
• With threaded fittings.

Different types of systems are used in different types of systems.

Non-pressure pipeline

Installation with the help of sockets is extremely simple.

The instruction is as follows:

• The pipe is inserted into the socket. The joint is sealed with a rubber ring, which is located in a special slot.
• Next, the joint is sealed with silicone sealant, which is used to process the joint.

Pressure pipe

Pressure pipelines are assembled most often by the adhesive method. Glue is a solvent that welds the mating parts. Therefore, this method of installation is also called cold welding.

The principle of such an assembly is not more difficult, the installation of free-flow systems - the end of the pipe is processed with the composition and immersed in the connecting fitting or socket. After this, it is desirable to turn the parts so that the composition is distributed evenly. Already after 1-2 hours the joint will completely harden and pick up its strength.

Tip! When installing the pipeline using the adhesive method, it is advisable to use glue that is recommended by PVC pipe manufacturers.

As for mounting on a threaded fitting, it is carried out by installing the fitting fitting into a pipe, after which the junction is crimped with a special lock nut. This method is similar to the installation of metal pipes.

Conclusion

Despite some disadvantages of PVC pipe products, they are widely used in various types of industrial and domestic pipelines. And in cases where the material deficiencies are critical, use pipes made of modified PVC - CPVC. From the video in this article you can learn more about this topic.