Replacing the gas valve: safety rules, instructions + analysis of popular errors
Pipes that supply gas to stoves or other equipment operating on this type of fuel must necessarily be equipped with individual taps in order to instantly shut off the gas supply in case of a dangerous situation.
The condition of the locking devices must be constantly monitored. You may need to immediately replace the gas valve in the apartment if it fails.
Common reasons for replacing a crane
Gas communications are highly reliable and even in difficult conditions they can serve for decades. The most vulnerable part of such systems are valves installed in the apartment, which due to constant loads quickly fail.
The question of replacing the locking mechanism may arise in the event of the smell of gas in the area of the crane. Failure of the device is indicated by external damage, for example, cracks or chipping of the device, as well as obstructed movement or excessively free rotation of the flywheel.
If any of the problems described above arise, you should call the staff of the Gorgaz or another organization serving your home. They will diagnose, advise a suitable model of the crane, and if necessary, carry out the replacement operation. Due to the increased danger, experts advise to change the crane before the occurrence of malfunctions immediately after the warranty period, which for most models is 10 years.
Types of cranes for gas
There are many types of locking devices that are installed on gas pipes. According to the features of their structures, two main groups can be distinguished:
Variety # 1: Cork
Until recently - the most common type of cranes for gas. The central part of such models is a conical element (tube) with a hole.
When the device is opened with the help of a flywheel, the hole in the conical part is aligned with the similar one in the pipe, so that the gas passes to the equipment. An oil seal is commonly used to connect cork valves to the pipeline.
Variety # 2: Ball
The main part of the locking element of this type is a spherical part made of strong metal. As in the cork counterparts, it has a hole that, when the handle is turned, is combined with the pipe, thereby ensuring the admission of fossil fuel to the corresponding device.
Such valves appeared relatively recently and quickly gained popularity due to their numerous advantages, namely:
- low cost;
- excellent functionality and safety margin;
- long service life;
- easy operation;
- opportunity to work in different environments at temperatures from -60 to +80aboutFROM.
Due to the combination of valuable qualities, at the present time, when equipping domestic gas systems, experts give preference to spherical structures.
According to the method of connection to pipes, several subspecies of ball valves are distinguished:
- Threaded(clutch). In this case, the valve is connected to the pipeline section with the help of a threaded part.
- Flange. Fastening is carried out with the help of flanges, fixed with bolts. Such devices are most often used in the transport of gaseous substances and oil.
- Welded. In this case, the valve is firmly welded to the pipe using an appropriate apparatus.
According to its purpose, ball valves are divided into three types:
- Three-way, used for the redistribution of gas flows;
- With heated body, used in cold climates;
- With leakage control.
There is also a division by the diameter of the passage.According to this indicator, the details can be attributed to two categories:
- DN 10-50 mm;
- DN more than 50 mm.
Another classification takes into account the nominal pressure that a crane can withstand. In this case, two types of devices are distinguished:
- PN 1.6 MPa 16 kg / cm2;
- PN 4.0 MPa 40 kg / cm2.
Ball valves can be made of different types of metal. The most widely used elements made of brass, zinc, steel 20 and alloys (09G2S, 12H18N10T), plastic.
The best qualities are demonstrated by brass devices, which may have a yellow or silver color (the latter is characteristic of nickel-plated models). Adaptations from this alloy can be recognized by relatively heavy weight.
Brass taps, having a robust universal design, are durable, low maintenance, and can be installed in any position.
Highlights for device selection
When choosing a locking mechanism for a gas pipeline, one should pay attention to such characteristics as:
- The diameter of the pipe.The crane must completely block the flow of gas into the apartment. If the locking element does not fit tightly to the pipe walls, then its tightness will be only partial, which can lead to serious consequences.
- Coincidence of the diameter and pitch of the thread on the pipe and tap.In this case, the installation of the device is quite easy. Installation of a locking element with a mismatched thread and diameter is in principle possible when using adapters, however this will require additional material and time costs for the purchase and installation of additional parts.
- The integrity of the shell.On the outer shell of the element should be no cracks, chips, flows, and other defects. Their presence indicates a violation of the rules of transportation, manufacturing or warehousing of parts, because of which internal malfunctions are also possible, as well as a shortened period of operation.
You should also pay attention to product quality, preferring models of well-known companies.
Step by step instructions for replacing the valve
The procedure for replacing the valve for supplying gas to the device is quite simple, however, it is extremely responsible, since natural fuel is combustible, and in conjunction with air and an explosive substance.Therefore, we strongly recommend to resort to the help of specialists who have been trained and have received permission to carry out such work.
To replace the valve on the pipe, you will need tools and materials:
- new locking mechanism, suitable for the pipe;
- two gas wrenches # 1 or # 2, one of which is required to loosen the thread, the second - in order to keep the bottom pipe stationary (this will avoid damage to the pipeline leading to the gas stove);
- means intended for sealing the place of fastening of a crane with a pipe (for this purpose, you can use ordinary linen thread, FUM tape, Tangit Unilok thread);
- flat screwdriver;
- graphite grease, grease or other lubricants;
- plug for pipe size of 0.5 inches with internal thread (when working together, you can do without this element).
If the thread or the diameter of the pipe and the valve do not match, you may also need extension cords, fittings, adapters.
The replacement process consists of a series of simple operations that must be carried out as quickly as possible to minimize gas leakage from the system.
First of all, cut off the supply of natural fuel to the apartment by setting the valve handle in a position perpendicular to the pipe.
After that, you can proceed to the dismantling of the old crane, which is unscrewed from the pipeline. If the process is carried out with difficulty, you can try to handle the threaded connection with the compound WD-40, due to which the smoothness increases.
If the room was previously installed welded valve, it will have to cut with a grinder, after which the pipes should be further cut the thread. At the place of the valve is removed put a temporary cap.
Thread is screwed on the thread for sealing. To do this, unscrew about 7 cm of the thread, and put it in the extreme groove of the thread, then wind the thread clockwise in each hollow.Having covered the thread with one layer of thread, you should continue winding in the opposite direction. After that, the laid insulation is covered with a layer of graphite grease or other suitable composition.
The cap is removed and a new crane is quickly strung on this place (it is important to make sure that its handle is in the “closed” position). The element is screwed by hand, the last turns are made with a wrench.
The procedure for calling specialists
The best choice is not to do your own manipulations, but to challenge the staff of Gorgaz. The procedure in this case is as follows:
- It is necessary to contact the company servicing the house, tell in detail about the problem and leave a request for a specialist call (before his visit it is better to refrain from using gas).
- At the appointed time, employees of the company will come to the apartment, who will perform the diagnostics and decide on the replacement of the crane. They will also tell you which model of the valve can be purchased on your own or offer to use the option that it has.
- Since Gorgaz specialists may ask for a gas supply contract, documents for a gas stove or last paid gas bills, they are best prepared in advance.
- Before the workers visit, it is also advisable to light the blue fuel and allow it to burn out in the pipe by shutting off its supply with a faucet at the gas meter. Such an operation will save time, since all manipulations can be carried out only after the pipeline is empty.
- It is also necessary to ventilate the room well by arranging a draft.
- When working with gas workers it is advisable to be close to them in order to monitor their work.
- After replacing the device, it is necessary to carry out an inspection together with the repairmen by testing the burner.
- Experts complete the act of the operation, assuring it with the seal of the service organization. The paper is also signed by the owner of the apartment.
- After all the works are completed, the windows should be left open for at least another half an hour so that all the gas will disappear from the room.
In the case of carrying out planned work on the replacement or repair of gas systems, the service of dismantling the old locking mechanism and installing a new model of the crane is free of charge, but the apartment owner acquires a fixture,as well as consumables at your own expense.
When calling specialists, you will also have to pay a small amount for the service rendered and pay for the device.
Inspection of cork without replacement
In some cases, it is possible to do without replacing the valve by cleaning and lubricating the cork device used.
The algorithm of actions in this case is as follows:
- First of all, you need to turn off the tap, setting its handle perpendicular to the pipe on which it is located.
- One of the gas keys to fix the sgon in the area of the valve, trying to further keep it in a stationary state.
- Using a second key, drive the sleeve and locknut onto a long thread.
- Try to unscrew the valve with a key, and then, with free rotation, unscrew it to the end by hand.
- After removing the part, cover the holes with a plug. Do not be afraid of high pressure, because the pressure in the pipe is only 3-5% higher than atmospheric.
- Place the cap on the thread, then screw it to the end without the aid of tools.
- Unscrew the valve from the sgon, removing layers of old insulation materials and paint.
- Use a screwdriver to unscrew the plug with a groove on the back side of the valve, removing the spring hidden under it, and then remove the conical plug from the body.
- Thoroughly clean the parts (plug, housing) from the remaining old grease, then apply a new composition to the element.
- After that, collect all the details of the gas valve in the sequence opposite to the above algorithm.
- Remove the cap and put in place the assembled part, after replacing the insulating materials with the thread.
- Screw in the thread and insulate the thread, then install the lock nut and the coupling in the working position.
In all cases, upon completion of the replacement of the crane, it is necessary to check the correctness of the assembly, and then invite experts.
Verification of work performed
After completion of all manipulations to replace the locking mechanism, it is necessary to check the tightness of the connections created. To do this, it is enough to apply a proven method: dilute soap with water and apply the resulting emulsion to the seat of the valve on the threads, as well as on the cork.If the joints are not tightly connected, there will be bubbles in the gas leaks.
In this case, you must immediately correct the defect. To do this, remove the valve and repeat all operations, trying to wind the thread and apply sealant more carefully and carefully.
Safety rules during the work
All manipulations with gas equipment are related to work with an increased level of danger. When working on the pipeline, the pipe is opened, which is why a gas leak occurs. This can lead to two serious hazards:
- Natural fuel is mixed with air, resulting in an explosive mixture. Any spark that may occur when the appliance is turned on (for example, a switch) may cause an explosion.
- With a higher concentration of gas, the air becomes unsuitable for breathing. Inhalation of the propane-butane mixture causes poisoning of the body, which can even be fatal.
To avoid emergencies, you must strictly observe the precautions.
Employees of the city gas service when carrying out equipment repairs, in particular, replacement of the crane must comply with the “Rules of technical operation and safety requirements in the gas industry of the Russian Federation” (PB 12-368-00 Resolution of the Gosgortekhnadzor of Russia of July 18, 00 №41, SNiP 2.04.08-87).
When conducting independent work, you must adhere to the following provisions:
- All work must be carried out with the windows wide open.
- The apartment must be completely de-energized, therefore for carrying out repairs it is important to have access to the panel and automatic devices.
- During the manipulation of the replacement of the gas valve in the room is prohibited to smoke, light matches.
- All work must be carried out exclusively in the daytime.
- The door to the kitchen where the work is done must be tightly closed. It is also advisable to plug all the cracks to avoid gas from entering other rooms.
- It is forbidden to shut off the valve on the common gas riser, since in this case the gas leak may increase many times, which will increase the danger of an explosion.
- All work is desirable to carry out together: this will speed up the process and avoid complications.
- You should not engage in self-replacement of the crane, if the gas pipe shows signs of corrosion or other damage, in this case, it is preferable to call the specialists.
When working, it is desirable to have a fire-fighting device (fire extinguisher) in the immediate vicinity.
Analysis of typical installation errors
Although the operation of replacing the gas tap is quite simple, for inexperienced craftsmen it may fail.
Typical shortcomings are:
- The impossibility of connecting the valve with a pipe.Most often it happens due to the fact that these elements do not correspond in their dimensions or thread. Adapters and extension cords of various shapes and sizes will help to fix the situation.In order not to get into a similar situation, it is desirable to take into account the parameters of the pipes at the stage of choosing a crane.
- Valve not bent. It is necessary to fix the thread manually, but at the end it is necessary to use a wrench. If this is not done, the connection will not be reliable enough, which will lead to gas leakage and instability of the structure.
- Turning the tap only with a wrench.When using the tool increases the possibility of damage to the part or breakage of the thread.
- Insufficient tightness of the connection.If checking a replaced valve indicates that natural gas is being released into the air, turn off the stove immediately and correct the error as described above.
Do not use cranes of inadequate quality. In order for the equipment to serve for a long time, it is important to choose models of well-known companies. It is advisable to use brass devices that require a minimum of maintenance with maximum efficiency and durability.
Silicone and other similar materials dry up, lose elasticity, as a result of which they begin to pass gas. To avoid this, it is better to use a lubricant based on graphite.
Conclusions and useful video on the topic
The video describes in detail the process of replacing the valve on the pipe leading to the gas stove.
Replacing the crane is a simple but very important process. Even if you have experience in carrying out similar work, according to the norms, you cannot do it yourself - you need to contact specialized services. Employees work there who have undergone appropriate training and received the necessary approval for the repair of gas systems.