Construction work today is impossible to imagine without the use of high-tech materials. The invention of polymers led to the emergence of new pipes. Such products are characterized by high strength and durability. And the ease of installation ensured the high demand for plastic pipe products in many industrial fields. We are talking primarily about PVC pipes, a special place among which are adhesive products.
Joining PVC pipes with glue is called cold or chemical welding.
Content
Specifications
The abbreviation PVC is an abbreviated spelling of the word “polyvinyl chloride”, which identifies an environmentally friendly polymer with a low melting point and low frost resistance. It is worth noting that the last two not quite attractive properties are offset by high stability and the same mechanical strength of this material. Actually, its physical characteristics give the following qualities to the PVC pipe:
- exceptional ring stiffness. The product is not afraid of water hammer and is able to withstand pressure up to 120 atmospheres;
- excellent indicator of resistance to temperature deformations. When the temperature reaches the maximum permissible mark, the size of the pipe will increase by only 5%;
- poor heat resistance. Loss of stiffness with an adhesive PVC pipe is fixed at a temperature of + 78 ° C. Therefore, it is not allowed to use this product when creating pipelines with a temperature of the working medium exceeding + 40 ° C.;
- fear of low temperatures. Polyvinyl chloride is able to withstand cooling without irreversible changes in its structure only to -15 ° C. Accordingly, if it is supposed to operate a PVC pipeline in regions where such a temperature indicator is not uncommon, the plastic line must be insulated.
From the operational characteristics, it is worth highlighting the following points:
- long period of operation without the need for to clean. Silting and clogging of engineering communications is prevented by the high smoothness of the inner surface;
- Ideal for arranging sewage systems. This is due, again, to a smooth inner surface and a small wall thickness;
- durability. One of the main reasons providing this property of adhesive PVC pipes is the excellent resistance of the polymer to UV radiation.
PVC adhesive pipes are available in different sizes and are used for water supply and sewage systems
Glue installation of PVC pipes
Glue for PVC pipes received a second name - cold welding. And this is by no means accidental. Such an adhesive composition ensures uniformity of the load, which, in turn, increases the strength and durability of the pipeline as much as if its elements were connected by real welding. This substance is a product of the decomposition reaction of polyvinyl chloride in solvents. The gluing process consists in the fact that at first the walls of the PVC adhesive pipe are softened, and then it is connected to the fitting also with softened walls. Therefore, this technology is also called chemical welding.
There is one caveat.Due to the fact that the chemical properties of additives and solvents can change, the selection of glue for PVC pipes must be carried out taking into account the type of thermoplastic compounds being welded. Typically, enterprises producing plastic water supply systems give recommendations on how to resolve this issue in the most optimal way. But in any case, it should be remembered that the same brand of glue cannot be used to connect the elements of the pipeline from CPVC and simple PVC (the abbreviation "CPVC" refers to chlorinated polyvinyl chloride).
Helpful information! This type of connection of these products is used very often. It provides greater tightness of the structure in comparison with the o-rings.
During installation, only those materials intended for this type of pipe should be used.
Types of glue and installation methods
All chemicals intended for the installation of PVC pipes for adhesive bonding, depending on the principle of action, are divided into two large groups:
For hot fusion. Using such means, they are connected PVC water pipes, sewer, vent and others. Subject to the rules of hot gluing, the connection will turn out to be reliable, durable and tight. The adhesive must be used in accordance with the instructions provided by its manufacturer. Only then will the optimum consumption of this substance be ensured and no claims will arise to the joints.
Important! Glue for PVC products is a flammable and combustible substance. Therefore, observe the fire safety requirements: in the room where the installation is carried out, do not smoke, and keep the composition itself away from fire. And do not let it come into contact with the skin!
Even with not very high-quality processing of the joints, the connection of the PVC adhesive pipes with this method will turn out to be quite tight. Installation is carried out using a special soldering iron or welding machine for plastic products. Moreover, such equipment does not have to be professional, you can do with a small device.
A soldering iron is needed to heat the ends of the mounted water supply components. Usually, several different nozzles are included in the scope of delivery, providing the ability to work with pipes of various diameters. The design of the soldering iron consists of heating elements and a sole. To properly weld PVC pipes, you need to know the temperature conditions of the equipment. But in any case, to achieve the required strength, all elements of the water supply should be heated to + 260 ° C.
For cold bonding. These funds, in turn, are:
- universal;
- specialized.
Their difference is that the latter are used exclusively for the installation of pipes, and the former can be used for any plastic elements that contain polyvinyl chloride. For example, using universal cold glue, you can solder linoleum.
After applying glue and joining the parts, hold them still for a while.
Cold installation of PVC pipes under glue is usually carried out by a bell-shaped method. To improve the reliability of the connection, in the factory, the surface of the narrow part of the pipe is given some roughness. During installation, the socket should be degreased from the inside. Then glue is applied to the pipe and chemical welding is carried out. Particular attention must be paid to the degree of cleanliness of the surfaces to be bonded. If it is insufficient, the strength of the joint can be significantly reduced.
Recommendations for choosing glue for PVC pipes
When choosing an adhesive composition, be sure to read the instructions and take into account the characteristics of the material. The following parameters are critical:
1. Hot or cold mix. This was discussed above.
2. Setting time. For a cold connection, most often this gap is:
- about one minute if the temperature exceeds the + 40 ° C mark;
- 4 minutes at room temperature.
The hot mix is characterized by the following numbers:
- drying time within 30 minutes;
- hardening time - 2.5 hours;
- full polymerization time - day.
3. Method of application, as well as storage conditions for the material. If these parameters are not met, the quality of the adhesive will decrease significantly.
The package contains information on such characteristics of glue for PVC plastic pipes as its viscosity, density and color. Considering the fact that polyvinyl chloride is soft, hard, corrugated, a number of manufacturers divide adhesive compositions into the following groups:
- for soft bases. This includes water and corrugated pipes;
- for solid foundations. Usually these are siphons, fittings, and other products.
Regardless of the degree of hardness of the material, modern adhesives quietly tolerate prolonged contact with hot and cold water. When purchasing similar products, stop your choice on proven brands. They will be briefly discussed below.
Reliability and tightness of the connection depend on the quality of the glue, so you should choose well-known brands of products
Popular brands of glue for PVC pipes
The main feature of the adhesive composition intended for joining PVC pipe products is the presence of polyvinyl chloride dissolved in tetrahydrofuran or other substances similar in properties. The following brands of glue for plastic products are the most popular:
TANGIT (Tangit, Germany). Designed for bonding joints PVC pressure pipes. The main advantages of this product include:
- reliable durable bonding;
- usability. Cans come with brushes;
- the glue has a certificate that allows it to be used in pipes for drinking water.
MARS (Russia). The basis of this glue is a solution of synthetic resin compositions in a mixture of organic type solvents. It is used for gluing pipes and fittings made of polyvinyl chloride. Advantages:
- strong connection;
- special stickiness.
In addition to these brands, experts recommend paying attention to the Phoenix and Vinylit adhesives. The compound formed by them will be no less reliable than that of the above samples.
