Gas supply home is determined by a certain level of comfort for the inhabitants of the home. Country houses, equipped with a centralized gas supply, are considered more comfortable.
For property owners who are unable to connect to a centralized network, there is an alternative. This is a gas-holder installation - a facility designed to provide an autonomous system with gas. Let's understand together the design and installation of gas holders for the house.
The content of the article:
- What is a gas tank?
- Tank mounting options
-
Assembly work
- How to mount the recessed tank?
- Electrochemical protection of gas holders
- Grounding and lightning protection
- Completion of the gas-holder system
- Conclusions and useful video on the topic
What is a gas tank?
The technical classification of a household gasholder device defines it as a liquefied gas accumulator. Thus, the gas-holder household is represented as a vessel intended for filling and storage of liquefied gas.
Of course, for such purposes a reservoir is used that meets the requirements for such installations. In addition, gas tanks under liquefied gas are completed with a full set of automatic tools that ensure safety during the operation of dangerous vessels.
This is one of the possible modifications of a domestic gas tank - a liquefied gas storage device widely used by private households as a source of cheap energy.
Hence the explanation suggests itself: workers and employees of special organizations are called to install, start up and conduct periodic monitoring of the gas-holder. This is comparable to approximately the case of everyday life when a gas boiler or gas column is installed in a house.
Well, and in addition to help: usually filling gas tanks is performed with a liquefied mixture of propane butane. These are low molecular weight hydrocarbons, a characteristic feature of which is an easy transition from a liquid state to a gaseous state. The frequency of the gas tank refueling process is usually no more than 1-2 times during a calendar year.
We also recommend reading the material, where we have understood in detail the cost of installing a gas-holder on the site. Read more - read Further.
Tank mounting options
Variations of mounting gas holders are limited in two ways:
- Installation outside.
- Installation underground.
For the first variant of installation, the characteristic condition is the installation in places of the territory of a private farm, where the sun's rays penetrate in a small volume. A site is also selected that is as protected as possible from external environmental factors (strong wind, landslides, soil movements, etc.).
There are no specific requirements for the tank capacity. The volume of the gas-holder is completely determined by consumer needs and wishes of the owners of a country house.
A ditch with a gas-holder of a household purpose shipped in it. Fastening of the tank is made of tape ties. The tank body is treated with a protective coating. Under the cover of the neck mounted automation
Underground gas tanks are mounted below ground level. The depth of the tanks is carried out to a depth when the upper level of the vessel is at the point of penetration not less than 0.6 m from the ground level.
At the same level with the ground surface or a little higher, only the filling neck of the tank remains. Under such conditions of burial, the possible freezing of the reservoir during the winter period of time is excluded, plus the tank of the gas-holder is reliably protected from possible mechanical effects.
Regardless of the type of installation, arrangement of gas holders on the household plot allowed no closer than 10 meters from residential buildings and various technical communications.
The project of installation of a tank for liquefied gas should provide easy convenient approaches / entrances for gas filling and maintenance. The presence of any engineering communications in the immediate vicinity of the building is not allowed.
The main design parameter for installation in a private sector is the volume of the gas-holder. According to the standards, the calculation is carried out with an emphasis on a square meter of usable floor space. The average gas consumption figure for areas with a temperate climate does not exceed 35 m3 on 1 m2. From here you can calculate the approximate volume of the tank.
Standard parameters to be used for installation of gas holders for domestic use. There may be some deviation from the standards upwards, but not much. Parameters directly depend on tank sizes.
A more accurate figure of volume is obtained if we calculate the value of gas consumption by a heating boiler. Here, the indicator of the rated power of the heating equipment is simply taken from the passport information and multiplied by the required gas flow. Then calculate the annual need for fuel.
When making calculations, one should take into account the fact that gas-holders are filled with liquid gas to no more than 85% of the tank volume.
Assembly work
The lion's share of household gas-holders is traditionally performed in the underground version. Such installation is considered more acceptable from the point of view of safety, plus a hidden gasholder does not spoil the landscape view.
The scheme on the basis of which the design is performed under the classic installation of household gas-holders using the mounting option by burial in the ground area. Based on this scheme, most autonomous gas stations are completed.
Also, taking into account the rather harsh climatic conditions of the middle band, installation of gas-holders in the underground version is given more preferences. So less problems with keeping the device in working condition at low winter temperatures.
How to mount the recessed tank?
Having chosen a place that is suitable for all requirements on the territory of a private farm, they organize work on plot marking, installation and excavation. The dimensions of the future pit that should be used under the gas tank, determined on the basis of the documentation of the tank.
The prepared trench is additionally prepared for loading containers:
- strengthen the bottom part;
- put a framework for the foundation with anchoring hardware on the bottom of the pit;
- pour the frame with concrete, including the base of the anchor bolts.
After solidification of the concrete pouring, the installation of the tank begins. For massive gas tanks may require renting a crane. Small gas tanks are lowered into the pit with winches or similar tools.
Unloading of the gas tank with a truck crane with the subsequent installation of the tank in the prepared pit. For the installation of smaller tanks often use manual lifting means.
The container lowered into the pit is placed on the foundation anchor studs, aligned with the horizon, using the linings under the paws, fixed. For fastening of tanks, the construction of which is without supporting legs, use metal tapes or cables.
Electrochemical protection of gas holders
At the next stage of installation of the gas-holder, work on the corrosion protection device is performed. Conventional protection methods are not suitable here. We need high-quality electrochemical technology.
As a rule, one of two methods of electrochemical protection is used:
- Active
- Tread
Active electrochemical protection is often used in tanks manufactured at Russian enterprises. This protection option is most effective for a metal subject to corrosion (in particular, steel 09G2S). Gas-holders made in Russia are made of this type of metal.
This is how the gasholder's active electrochemical protection scheme looks like, which is used with domestically produced tanks. Cost option, given the need for constant consumption of electricity
Protection by the cathode is carried out by an electrical circuit, the power consumption of which is 0.75 - 0.90 kW. Quite a costly station for a private farm, but no other solution has yet been invented.
An alternative for an active protection station is a tread anode / cathode system. This design also has its drawbacks, but it saves the consumer from the cost of electricity. It is applied complete with tanks of import production. The principle of operation of such a system is based on the "interception" of active corrosion by a metal with a high electronegative potential (for example, aluminum).
A variant of the electrochemical protection of the tread type used with the majority of imported products. It does not require electricity, but there is a need to replace the work item as it is worn.
For both methods of electrochemical protection, appropriate calculations are needed with emphasis on the type of capacitance, its dimensions and other factors. Calculations are determined by the place of installation of the electrochemical protector or the power of the active cathodic protection. At the design stage of the installation of the gas tank, this moment must be taken into account.
Tread systems seem more attractive in terms of economy. But they can not be applied to all types of tanks.
Grounding and lightning protection
The functions of grounding gas holders, in fact, can take over the system of electrochemical protection. However, it is necessary to protect the individual gas-holder from lightning discharge individually in any case.
With regard to installation installation, the following actions are possible here:
- Making a ground loop.
- Installation and deepening of the contour around the perimeter of the pit to a depth of at least 1.8 m.
- If necessary (for mobile soils) reinforcement contour reinforcement elements.
Detailed instructions on how to make a ground loop with your own hands can be found in this material.
Ultimately, all the installation elements included in the gas distribution system need to unite in a common ground loop, so as to ensure comprehensive protection (according to the safety regulations 12-609-03). The resistance value of the common circuit is allowed at 10 ohms and no more.
Industrial gasholder, reliably protected immediately by a group of lightning rods. In the case of a domestic tank, usually only one lightning conductor is required. But in any case, lightning protection is required
The lightning rod is installed at a distance of at least 12 m from the border of the gas-holder pit and is connected to the ground loop. The height of the mast of the lightning rod is not less than 7 m.
Completion of the gas-holder system
After completing all installation measures for the installation of a gasholder, the system must be checked for leaks. Pressure testing is permissible to hold compressed air. The value of the test pressure is taken from the calculation of the working pressure of the tank (in the passport), increased by one and a half times. To set the test pressure to the tank connects the air compressor.
The process of pressure testing of the gas-holder installed on the territory of one of the private farms. Along the same line, after the installation is started up, the liquefied propane butane will have to be pumped into the tank.
The pressure set should be maintained in the smooth phase mode. At the same time, it is imperative to control the pressure level by gauges. One pressure gauge is placed directly on the output fitting of the compressor, the second on the upper side of the tank.
After a set pressure level corresponding to the test value, stop the compressor, close the valve on the air supply line and leave the system for 5-6 hours of exposure. Then check the pressure drop. If the decline is greater than 0.5 - 0.8 ATI, the system has a leak. A decrease of less than these values indicates satisfactory sealing.
The gas-holder installed and checked for tightness is filled up with river sand. Backfilling is done at 80% of the depth of the pit. The rest is covered with soil
Having completed the pressure test, proceed to filling the pit with the reservoir. Backfilling is carried out by fine river sand to the level of 0.3-0.5 m below the ground level. After completing the filling of sand throughout the area of the pit, the embankment is thoroughly rammed or allowed to settle for 1-2 days.
Then the remaining upper area of the pit is filled up with soft shallow soil to the level of the surface of the whole territory. The last stage is pressure testing of the gas supply line to the building. With the normal completion of the crimp installation can be considered complete.
Conclusions and useful video on the topic
Briefly and succinctly about the autonomous gas supply to a private enterprise:
Judging by the description of the design and installation process, it is quite possible to provide a private house with an autonomous gas station with small forces and with acceptable costs for the family budget. And quite a few owners of suburban real estate, remote from centralized gas communications, use this opportunity. The result is obvious - convenience and increased life comfort.
Do you have practical experience of using and installing gas holders? Or do you want to ask a question on the topic of the article? Please leave comments, ask questions, share experiences in the box below the article.
