- Where to install the balloon
- Which gearbox to choose
- What hoses and tubes to use for connections
- Cranes and other fittings
- Modification of the plate for cylinder gas
- Commissioning the plant
The use of bottled gas requires a thorough approach to safety and ease of use. We propose to consider the simplest example of connecting a propane cylinder to a gas stove: connection diagram, shut-off and control valves, organization of storage conditions.
Where to install the balloon
The main generalized requirement for the use of gas cylinder equipment can be called ensuring the safety of people. For this reason, gas cylinders are not recommended to be installed in inhabited rooms and technical rooms connected to a residential building directly or through ventilation..
Propane gas is distinguished by its high density. Cylinder gas is heavier than air and can accumulate in the lower floors of buildings. Therefore, it is strictly not allowed to install cylinders in underground or technical rooms below ground level. If in the usual case small leaks do not pose a danger due to constant air exchange, then in lowlands the gas can accumulate for a long time to explosive concentrations. It is possible to install gas cylinders in accordance with SNIP 42-01-2002 only inside buildings not higher than 2 floors, in an amount of no more than one and at a distance of 0.5 m from gas stoves and 1 m from heating devices.
To make the installation safer and to prevent unauthorized persons from accessing the gas equipment, the cylinders are placed either in a room with a separate entrance or in an outdoor metal cabinet. It is especially important for outdoor installation to take into account the operating temperature. Cylinder gas consists of a mixture of propane and butane, each with a different boiling point. When the cylinder is cooled below 0 ° C, only propane will evaporate from the mixture, while the remaining butane in the cylinder will not be efficiently used. At lower temperatures, it is possible to completely stop the flow of gas to the stove.
The main way to achieve normal operation at low temperatures is the use of so-called winter gas mixtures that can evaporate at temperatures down to -40 ° C. However, the problem is that such gas may be in seasonal shortage, moreover, the possibility of refueling with a mixture of mediocre quality cannot be ruled out. There are two ways to resolve the issue with a guarantee: either insulate the attached metal cabinet, counting on the penetration of heat from the building, or additionally heat the cylinders using a self-regulating cable.
The height of the cabinet should be at least 20-30 cm higher than the height of the cylinders so that they are not installed on the floor, but with a gap, for example, on two metal slats or a high pallet. In this case, the cabinet must be protected from the penetration of melt, rainwater and heating from sunlight above 40 ° C.
Which gearbox to choose
Gas stoves have built-in nozzles designed for constant gas pressure, while the pressure in the cylinder decreases with consumption. To normalize combustion, the cylinder is not connected directly to the stove, but through a reducer. LPG reducers are called propane valves and are usually red or metallic in color..
The main characteristics of the reducer – outlet pressure and throughput – must be matched to the parameters of a single plate. If it is not possible to set the nominal pressure value, you should purchase an adjustable type reducer and adjust it manually. Also, adjustable reducers are shown directly when using cylinders with a capacity of 20 liters or more, where the pressure drop is more pronounced..
Reverse gearboxes are recommended for domestic propane applications. Due to the low pressure values of liquefied gas and the small difference at the inlet and outlet, the use of multi-stage reducers is economically unreasonable. The only requirement is to use, in conjunction with composite cylinders, reducers provided for by their technical standard..
A separate nuance in the choice of a reducer may be the temperature mode of operation of cylinders. The fact is that during the evaporation of a liquid gas, an intensive decrease in its temperature is observed. So, if initially the propane-butane mixture is at a temperature of -5 …- 10 ° C, in the reducer itself, its temperature may drop to the condensation mark, because of which the gas becomes liquid again, and the reducer stops working. One of the ways out of such a specific situation is to use gearboxes with a built-in heating system..
What hoses and tubes to use for connections
According to the rules for the safe operation of gas equipment, it is not allowed to use oxygen and hydraulic hoses for laying gas pipelines. This is due to the high temperature difference between the transported gas and the external environment, which leads to accelerated degradation of the hose material and the appearance of microscopic leaks. With the properties of liquefied gas to accumulate in rooms, such phenomena pose an increased danger.
There are three options to connect a gas cylinder to a stove. The first is to use special flexible rubber hoses for flammable hydrocarbons. In this case, their connection to the gearbox is carried out through a standard fitting with reinforcement with a screw clamp. The same fitting is installed on the inlet of the gas stove, the hose is also connected to it with a clamp. If it is necessary to connect two hose sections, do not use double-sided fittings; instead, use threaded connectors with double shank crimping with clamps. A distinctive feature of such connections for gas pipelines is the tapered thread and the absence of elastic seals..
The connection of the plate to the cylinder using flexible hoses has a number of limitations. The length of the hose should not exceed 150 cm, and its routing should remain visible for constant monitoring of the condition of the jacket and the absence of damage. Some of the prohibitions can be partially circumvented by using metal bellows hoses. They form a semi-rigid becoming, which can have an almost unlimited length, while maintaining resistance to temperature effects and mechanical damage..
At the same time, safety rules prohibit the passage of flexible and semi-flexible channels through walls, where their condition cannot be assessed visually. If it is necessary to connect the stove with a cylinder installed on the street, a steel pipe case must be embedded in the hole in the wall with cement mortar. Inside the case there is a steel tube of a smaller diameter with threads at both ends, the space between the walls is filled with a plastic sealant, for example, foam or silicone. The connection of bellows or flexible hoses must only be made using threaded adapters of the appropriate type..
Cranes and other fittings
At the point where the gas pipeline is connected to the stove, a gas valve must be installed to block the gas supply in the event of a stove malfunction. It can be either a yellow flywheel ball valve or a gas plug valve. The disadvantage of the latter is the need for periodic maintenance..
Another useful addition to a gas pipeline can be a flow meter. Its inclusion in the transportation chain will help to timely respond to the exhaustion of the mixture in the cylinder and to replace it. The metering device should not have the outstanding accuracy required to control the gas consumption in the main grids, a device worth up to 2 thousand rubles will be enough.
If several cylinders are connected at the same time, a connecting ramp can be used. Its installation helps to reduce the rate of gas evaporation from each cylinder and to make the risk of mixture freezing in the reducer less likely. The installation of the ramp can be done independently with any material for the manufacture of the gas pipeline.
Modification of the plate for cylinder gas
Not every stove can initially run on liquefied gas. The main obstacle is the higher operating pressure, due to which there is a lack of oxygen in the burners, which is reflected in the yellow color of combustion and the appearance of soot.
The situation can be corrected by replacing the methane jets with LPG nozzles. They have exactly the same form factor, but the hole diameter is slightly smaller. If you plan to connect a new stove, most likely a set of nozzles for liquefied gas should come with it. If there are no replacement jets, they can be purchased at a reasonable price..
The diameter of the openings in the liquid gas nozzles depends on the pressure in the outgoing chamber of the reducer and the burner power. So, diameters of 0.43–0.6 mm for a pressure of 50 mbar and 0.5–0.75 for a pressure of 30 mbar are considered standard values for stoves on liquefied gas. Individual board manufacturers can set their own diameters, however, using nozzles with different hole diameters may void the warranty.
Replacement of nozzles can be done in two ways, depending on the plate design. In the simplest version, it is enough to remove the burner body and look inside the landing sleeve. If a nozzle is visible at the bottom – a hex head with a hole in the center – it is unscrewed with a 7 or 8 mm socket wrench and the nozzle is screwed in for replacement. If a cone with a hole is visible inside, you will have to remove the top panel by unscrewing several bolts on the sides from different sides. The nozzle itself in this design option is not twisted, it is pressed onto the stuffing box seals. You need to unclench the mustache of the crimp sleeve, move the nozzle down with the inlet tube, and then pull the nozzle out of the landing fitting and install a new one.
Commissioning the plant
The entire installation of the gas pipeline is carried out without connecting it to the cylinder. When the tubes or hoses are connected to the plate and interconnected, the reducer nut is screwed onto the cylinder valve and tightened. Then, if a flexible hose is used, it is put on the fitting and squeezed with a clamp. If bellows tubes are selected, the union must be unscrewed from the gearbox housing and a threaded adapter of the appropriate size must be screwed into it..
When the unit is assembled, you need to open the valve on the cylinder and, by turning the regulator of the reducer, set the required outlet pressure. Once the gas has entered the tubing and hose system, each connection is thickly coated with a soap and foam solution and checked for leaks. After the integrity of the gas pipeline is confirmed, you can open the stove tap and try to light up the burners in sequence..
If each of them smokes or the flame burns in a color other than blue or greenish, it is necessary to reduce the pressure with a valve on the reducer. If the malfunction is typical only for some burners, it means that the jets for them are selected incorrectly. If the burner goes out in the minimum fire position – adjust the low-flow screw on the stove tap or try to slightly increase the pressure with the reducer screw.