The operating parameters in the gas system are maintained due to a number of conditions, among which the selection of a suitable equipment and pipe material, installation of regulators, competently performed installation, compliance with the rules exploitation. To stabilize the temperature, no special efforts are taken, but in vain.
Despite compliance with all the requirements for the installation of gas pipes, users often encounter condensation or freezing of the fuel mixture. To prevent this from happening, thermal insulation measures are carried out. In this article, we will consider how to insulate a gas pipe on the street so that the system functions normally and even in severe frosts provides the house with heat. We will supplement the material with visual photos and useful videos with recommendations for pipe insulation.
The content of the article:
- Do I need to insulate the gas pipeline?
- Preparation of pipes for insulation
-
Popular types of materials + instructions
- Option # 1 - thermal insulation based on mineral wool
- Option # 2 - PPP and PPU shell
- Option # 3 - Thermaflex polyethylene "coat"
- Option # 4 - Self-Regulating Heating Cable
- Conclusions and useful video on the topic
Do I need to insulate the gas pipeline?
It is unlikely that you have come across insulated pipes leading from gas distribution stations to residential buildings in urban conditions. Usually, a gas pipeline is laid underground - and then only waterproofing is done, without insulation. Or aboveground, when pipes also protect from atmospheric and mechanical damage, without worrying about their thermal insulation.
There is also a minimum of information on additional insulation in the documents - and in SNiP 42-01-2002 (about systems in general), and in SNiP 41-03-2003 (on the thermal insulation of pipelines).
An example of an outdoor low-pressure domestic gas pipeline that is supplied to residential buildings. External protection of metal pipes consists of anti-corrosion treatment and application of signal paint
The lack of thermal insulation is explained by the properties of methane gas, which is supplied to the city stoves and columns. Its content in the fuel mixture reaches 70-93%, and the freezing point is -182.5 ° C. This means that even if the methane is diluted with other impurities, it will not freeze in the winter conditions of the northern regions of Russia.
If methane is not subject to freezing, then propane-butane mixture filled with cylinders and gasholders, sensitively reacts to a decrease in temperature. That is why the owners of private houses have to either independently or by the efforts of employees service organization insulate sections of the gas pipeline located on the street.
Liquefied gas cylinders cannot be stored in a living room or behind partitions, therefore they are placed outside, next to the kitchen, in a metal protective cabinet
Three critical areas can be identified that potentially require additional thermal insulation:
- a piece of pipe from gas cylinders to an inlet in the wall of the house;
- pipe from the basement entry into the house, if gas is supplied from gasholder;
- a pipe section located in an unheated room - in a cold corridor, storage room, etc.
The underground gas pipeline does not require additional insulation. If it is enclosed in a special case-shell made of polyurethane foam, then in order to protect it from mechanical damage. The basement outlet of the polyethylene pipe from the ground is placed in a case, it is also not thermally insulated.
Passing through the wall, according to the rules, also produce in case: the pipe is enclosed in a piece of metal pipe of a larger diameter, and the voids are clogged with tow mixed with bitumen. Thus, this small section of the gas pipeline is already insulated.
Whether it is necessary in a particular case to insulate a gas pipe on the street is up to the owners of the house. If the fuel supply system works without interruption, then thermal insulation is not needed.
Preparation of pipes for insulation
The fragments of the gas pipeline listed above, requiring additional thermal insulation, can be steel or polyethylene - therefore, the materials for insulating such pipes you need to select the most suitable ones. It is better to wrap PE pipes with elastic sheet or tape material, and metal pipes - with a heating cable or place inside a PP shell.
In any case, the gas pipeline must be prepared before insulation. The recommended air temperature for installation work is +10 ° C, so it is better to postpone the activities until the warm season.
Before starting work, turn off the gas supply system, and after the end of the insulation measures, start it up no earlier than 24 hours
The insulated surface must be thoroughly cleaned of dust, dirt, grease, adhered street debris. We recommend using a special diluent cleaner based on ethyl acetate. If the thermal insulation is to be glued to the painted surface, make sure that there is sufficient adhesion.
Useful tips that will come in handy during the installation of pipe insulation:
- if you plan to use insulating tees, corners, bends, get ready to fix them first, and then isolate straight sections;
- expect that the glue, if used, will have to be applied to both the surface and insulation, and when gluing the ends - both to the ends, and about 2 cm to the inner surface thermal insulation;
- stretch the insulation during installation, taking into account the linear expansion of the pipes;
- to give an overall appearance, place all seams on the side of the wall.
We recommend that you prepare a set of tools in advance: a glue brush, a stationery knife, a compass, scissors, punches, a miter box, a ruler, a tape measure, a marker. A spatula is useful for puttying.
To treat a metal pipe with an anti-corrosion compound - and this is a necessary step before putting on the shell or polyurethane "coat" - prepare a small flat brush
Before fixing the self-regulating cable, the steel pipe is also covered with a protective paint in 2 layers and produce grounding.
Popular types of materials + instructions
Consider the types of insulation that are more appropriate to use in modern conditions. It makes no sense to wrap pipes with glass wool or cover them with foam, if there are effective materials based on expanded polystyrene or polyurethane foam. Moreover, in addition to straight segments, you can also purchase ready-made curly elements - tees, bends, corners.
Several useful recommendations on how and how to insulate a gas pipe from condensate will help you independently eliminate the emergency and maintain the functioning of the gas pipeline until arrival specialists.
Option # 1 - thermal insulation based on mineral wool
Often, inexpensive mineral wool cylinders, ordinary or foil, are used to insulate pipelines. The advantages of insulation include incombustibility, environmental friendliness, biological resistance, quick and easy installation, excellent thermal insulation properties.
The main disadvantage is fear of moisture. If water gets inside the cylinder, the material collapses, and rust forms on the metal pipes underneath.
Basalt wool cylinders are produced in various standard sizes: they differ in length, thickness and diameter. Factory products meet the requirements of GOST 23208-83
Cylinders that are not lined, that is, not covered with foil, cannot be used in a humid environment, therefore, they are not suitable for thermal insulation of a gas pipeline outdoors. They can be used in dry, closed, unheated rooms where the temperature in winter drops below 0 ° C.
The requirements for the installation and operation of mineral wool insulation can be found in SNiP 41-03-2003developed to replace SNiP 2.04.14-88.
Warming rules:
- It is better to start fastening the elements from flange connections.
- The cylinders are fixed using bandages, packing and aluminum tapes.
- Non-masticated products must be wrapped with reinforced tape. It is also used if the top layer of foil cylinders is damaged.
- If it is noticed that moisture has penetrated under the insulation, it must be replaced.
Before installation work, steel pipes must be treated to prevent corrosion. But it is better, if possible, to abandon the use of mineral wool and choose a moisture-resistant insulation.
Option # 2 - PPP and PPU shell
Hard covers made of polyurethane foam and expanded polystyrene, like basalt shells, are actively used. They have all the advantages of mineral wool, moreover, they practically do not absorb moisture.
They can be used both indoors and outdoors, and the main conditions for a long service life are compliance with installation rules and tightness.
In addition to the hard shell, a sprayed analogue is also used, which is applied by spraying. As a result, the pipe surface is covered with a dense sealed layer that does not allow moisture and sunlight to pass through.
In terms of technical characteristics, mineral wool is inferior to PU foam insulation, the comparison results are shown in the table:
It can be concluded that the main disadvantages of basalt wool are recognized as hydrophobicity, a decrease in the quality of thermal insulation when squeezed, and a relatively short service life.
Products usually consist of two equivalent halves, which are connected during installation according to the principle "Thorn-groove". To achieve maximum tightness, seams and joints are sealed with foil tape. But a hard shell is not suitable for insulating fittings - you will have to use other materials.
It is important that the pipe is absolutely dry before installation! Even low humidity can cause a greenhouse effect and the development of corrosion.
Option # 3 - Thermaflex polyethylene "coat"
Thermaflex products have become widespread due to their versatility, good thermal insulation properties, lightness, ease of fixation. This is thermal insulation in the form of honeycomb tubes made of polyolefin or polyethylene. Suitable for all types of pipes, including gas pipes.
Waterproof material is distinguished by wear resistance, durability, resistance to aggressive environments, it is used to insulate surfaces with a large temperature range - from -80 ° C to +95 ° C
In addition to pipe and sheet material, the manufacturer produces several types of glue for attaching to pipes, polymer and aluminum tape, thermal tape, cleaner, clips and hangers.
Instructions for use:
- Cut a straight piece of pipe material along the technological seam along the entire length, trying to keep the knife perpendicular to the surface.
- Put insulation on the pipe so that the cut edges do not touch.
- Apply glue to the cut, adjacent parts of the pipeline and the inner side of the thermal insulation - this is necessary so that the element does not move.
- Wait a few minutes for the glue to dry (from 2 to 12, depending on the pipe temperature);
- Connect the edges along the cut line, neatly, from the ends to the middle.
- Use clips for greater reliability., placing them along the seam with an interval of 20 cm.
Before gluing the next piece, glue the end part, including the pipe surface. After 24 hours, remove the clips, and glue all the seams with tape.
Insulation guidelines for various types of insulation - straight sections for unmounted and mounted pipes, as well as right angles and tees
The pipe Thermaflex is designed for insulating gas pipelines with a diameter of up to 159 mm, if the pipe or shaped element is wider, we recommend using sheet material.
Surplus material will never disappear: along with gas pipes, it can also be thermally insulated pipelines Cold water supply and hot water supply, sewerage, reservoirs.
Option # 4 - Self-Regulating Heating Cable
Heating cables are used to protect pipelines from freezing or to maintain the desired temperature.
Owners of private houses suffering from condensation and freezing of fuel in the cold season respond positively to self-regulating cable - it really helps to forget about the troubles associated with the use of blue fuel.
Self-registers are also valued for saving electricity: when the temperature of the pipeline rises, they reduce heat generation. At the same time, the cables do not burn out and do not overheat.
There are no restrictions on use: the cable is used for copper, steel, composite pipes, threaded and unthreaded. If an aluminum thermal tape is additionally fixed for installation on plastic, then it is not needed for steel gas pipes.
The cable is laid in two ways:
- Extending 2 or more parallel straight lines the entire length of the pipeline. For a 50 mm gas pipe, 2 lengths are sufficient.
- Coiling the cable along the entire pipe, including tees and elbows.
To protect both the pipe and the cable, heat insulation is put on top in one layer, preferably polymeric. If a bituminous or solvent containing insulation is used, instead of the usual one, you should purchase a cable with fluoropolymer shell - it is important!
The installation procedure is simple: the cable is fixed on a previously prepared surface of the gas pipeline using one of the indicated methods, a heater is put on from above, and fixed with tape or thermal tape. Then they are connected to the network using an adapter sleeve. We recommend to see the detailed cable installation instruction.
Conclusions and useful video on the topic
Heating cable installation methods:
One of the options for attaching the PPU shell:
How to insulate pipe joints with Energoflex:
Thermal insulation with rubber sheet material:
As you can see, the materials and methods for insulating gas pipes in a private house can be different. Their choice depends on specific conditions: location and size of the gas pipeline, technical characteristics, cost. All materials listed in the article are universal, that is, they can be used for thermal insulation of any pipe communications.
Despite the ease of installation of heaters, we recommend that you first consult with a gas service specialist in order to exclude the wrong choice of material, and penalties from the side of the service organization.
Have you recently insulated a pipe and want to share your experience with other users? Write your recommendations, add photos of the finished work, participate in discussions - the comment form is located below.
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