Types and features of insulation of galvanized steel pipes

Steel products have long been used for laying engineering communications in various areas. Due to their reliable performance, they continue to be actively purchased despite the introduction of many new plastic and polyethylene products.

Varieties and applications

The most popular of all types of steel products are galvanized pipes, which differ in purpose:

• to create a water supply;
• conducting household and business communications;
• gas pipelines;
• heating system installations.

Depending on the application, they are made in different diameters, according to established standards:

• For conducting water and gas, pipes manufactured in accordance with GOST 3262 are used;
• Electrowelded products meet the standards of GOST 10704;
• Seamless and profile.

To install a water supply system in an apartment, as well as create a heating system, pipes made in accordance with GOST 3265 are used. They have a number of advantages:

• Anti-corrosion resistance. This is especially important in the application of steel products. Thanks to the galvanized coating, the plumbing does not rust and lasts much longer;
• Service life of systems from galvanized metal exceeds 25 years.;
• Compared to conventional metal elements of the system, they are much lighter. This simplifies the work and transportation of these products;
• Convenient when creating the desired design. They can be cut to the desired dimensions, welded and joined in a specific configuration.

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Outwardly, all steel products look the same, they differ in wall thickness. To create plumbing and heating in a residential area, elements of an average accuracy class are used. If outdoor use is intended, then insulation of all galvanized steel pipes will be required, otherwise the liquid in the pipeline may simply freeze and create a lot of problems with the life support of the house.

First you need to understand the types and features of insulation.

Types of insulation

The coating with an insulating layer can be applied from the inside and outside, on a pipeline with a diameter of constituent elements from 57 to 530 mm. To apply the top layer, extruded polyethylene is used. Insulation of the inner walls is carried out with liquid heaters. Each method of insulation has its positive and negative sides, which must be considered.

Foam polymer

PPM insulation is carried out in three protective layers:

• The first protects against liquid ingress to the surface, protecting against corrosive processes. The layer density reaches 100 mm;
• The second layer is thermal insulation. The foam polymer material has a porous structure, this allows you to increase the temperature of the passing liquid. The density of this layer depends on the climatic conditions of residence;
• The top layer is used to protect against mechanical damage, as well as for waterproofing. Density reaches 15 mm. It is on this indicator that the strength of the entire structure depends.

Pipes with PPM insulation are manufactured at the factory in finished form. They are used for laying engineering communications underground or in an open way.

polyurethane foam

PPU insulation for galvanized pipes is made from Izolan and Varatek materials. To increase the reliability of the insulation, the coating has an upper galvanized layer.

Products with this insulating material are manufactured in accordance with GOST 30732. According to the standards, the coating must comply with the following characteristics:

• the layer thickness must be at least 60 kg per cubic meter;
• coating strength during deformation more than 0.3 MPa;
• thermal conductivity coefficient from 0.033 W at a heating temperature of 50ºС.

These parameters make it possible to use products with PPU insulation for laying heating mains with increased pressure up to 1.5 MPa.

Reinforced (double)

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Such an insulating coating protects metal elements from the effects of electric current. It consists of several layers, which are divided into the main and additional parts. Reinforced insulation of galvanized steel pipes is regulated by GOST 16703 and is a single design system that provides protection against electrical damage comparable to double insulation.

This type of product is used in the creation of heating networks and large gas pipelines, in the repair of a building or office. They are not reliably protected from corrosive processes on the outside, due to this, their service life reaches more than 30 years. At the same time, it is possible to install and assemble the structure in soil with high humidity and even in water. The use of these pipes solves many difficulties with the installation of an external pipeline. They are not afraid of temperature changes and bad weather conditions, which will allow them to be used in places of residence with a harsh climate.

Internal

This type of insulation is carried out at the factories of manufacturers of galvanized metal products and is divided into two types:

• Anti-corrosion. It is necessary to protect against the appearance of rust and corrosion of the inner walls of pipes. The inner surface is the most vulnerable place, since it is in direct contact with the liquid, and also experiences increased pressure on the walls of the structure;
• Antifriction. Its tasks include increasing the throughput of the structure, as well as increasing the resistance to internal friction that accompanies high-pressure fluids.

The use of internal insulation allows you to increase the service life, protect against the ingress of biologically harmful microorganisms, chemicals into the water, and reduces the level of roughness.

Products with an internal protective layer are distinguished by:

• Resistant to deformation. Insulation increases the elasticity of the walls, allowing them to withstand high temperatures;
• Reliable protection against corrosion and rust;
• High coefficient of resistance to water hammer, pressure drops.

The choice of internal insulation directly depends on the place of operation of the water supply.

extruded polyethylene

Thermal insulation of a pipe made of galvanized steel using extruded polyethylene takes place in an industrial environment. It has 3 layers:

• The inner layer, made of epoxy resin, is necessary to eliminate small defects on the surface of the pipe;
• The middle layer serves as a fixing base;
• The top applied layer is made of extruded polyethylene.

Due to the construction of a puff cake, products with such insulation have a number of undeniable advantages:

• Environmental friendliness. Polyethylene is safe for the environment and does not harm human health;
• Hydraulic resistance increases the service life of metal products;
• Increased coefficient of resistance to temperature extremes and pressure surges;
• Anti-corrosion protection. Thanks to water tightness contact with aggressive environment for metal is excluded. This protects the pipeline from rust.

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Resistance to high temperatures allows the use of this material for insulation of chimneys and heating systems.

Rubber-bitumen mastic

Pipe insulation using rubber-bitumen mastic is carried out only to protect against moisture penetration, that is, from the occurrence of metal corrosion. It does not affect other indicators (pressure, resistance, thermal conductivity).

Insulation work is carried out according to the standards defined in the GOST 5116 standards. It is applied in several layers:

• First, the surface of the product is primed for better adhesion to the metal surface;
• Next, apply mastic;
• The third layer is laid non-woven fabric, which acts as a protection against moisture;
• The last layer is a wrapper that protects the pipe from mechanical damage.

I use products with rubber-bitumen mastic to create water pipes. It is not recommended to use as a material for creating a heating system, as they do not tolerate temperatures below 10 and above 40 degrees.

Any insulation can increase the characteristics of galvanized metal pipes. To do this, it is important to choose the right one in accordance with the tasks. Therefore, when choosing products with insulation, carefully study all the technical specifications in order to avoid many problems in the future.