Replacing a gas valve: safety rules, instructions and 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 so that in case of a dangerous situation they instantly shut off the gas supply.
The status of the locking devices must be constantly monitored. You may need to immediately replace the gas valve in the apartment if it suddenly fails.
Here you will learn all about the reasons for replacing faucets for gas pipes and the choice of a suitable device model. For independent masters, we provide step-by-step instructions. A detailed description of the work will help not only to replace the locking device, but also to monitor the actions of gas service workers.
The content of the article:
- Common Crane Replacement Causes
- Types of gas taps
- Highlights for selecting a device
- Step-by-step valve replacement instructions
- The procedure for calling specialists
- Revision of the cork crane without replacement
- Verification of the result of actions taken
- Work safety rules
- Analysis of typical installation errors
- Conclusions and useful video on the topic
Common Crane Replacement Causes
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 when there is a gas odor in the tap area. External damage, for example, cracks or chips of the device, as well as obstructed movement or excessively free rotation of the flywheel, also indicate a malfunction of the device.
If one of the described problems occurs, you should call the employees of gorgaz or another organization serving your home. They will carry out diagnostics, advise a suitable crane model, and, if necessary, carry out a replacement operation.
Due to the increased danger, experts advise changing the crane before malfunctions occur immediately after the expiration of the warranty period, which for most models is 10 years.
Types of gas taps
There are many types of locking devices that are installed on gas pipes. According to the features of their designs, two main groups can be distinguished:
Variety # 1: Cork
Until recently, the most common type of gas taps. The central part of such models is a conical element (cork) with a hole.
When opening the device with the help of a flywheel, the hole in the conical part is aligned with the same in the pipe, so that the gas passes to the equipment. An oil seal is usually used to connect cork valves to the pipeline to create a seal.
Variety # 2: Ball
The main part of the locking element of this type is a spherical part made of strong metal. As in cork counterparts, it has an opening that, when the handle is rotated, is combined with the pipe, which ensures the access of natural fuel to the corresponding device.
These valves appeared relatively recently and quickly gained popularity due to their numerous advantages, namely:
- low cost;
- excellent functionality and safety margin;
- long service life;
- simplicity in operation;
- the ability to work in various environments at temperatures from -60 to +80aboutWITH.
Owing to the combination of valuable qualities, at present, when equipping household gas systems, specialists prefer ball structures.
By the method of connecting to pipes, several subspecies of ball valves are distinguished:
- Threaded (coupling). In this case, the faucet is connected to a section of the gas pipeline using a threaded part.
- Flange. Fasteners are carried out using bolted flanges. Such devices are most often used in the transportation of gaseous substances and oil.
- Weldable. In this case, the faucet is firmly welded to the pipe using an appropriate apparatus.
According to their purpose, ball valves are divided into three types:
- Three-way, used for the redistribution of gas flows;
- With heated case, used in cold climates;
- With leakage control.
There is also a division according to 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 the 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 are elements made of brass, zinc, steel 20 and alloys (09G2S, 12Kh18N10T), and plastic.
The best qualities are demonstrated by brass devices, which can have yellow or silver color (the latter is typical for nickel-plated models). Devices made of this alloy can be recognized by their relatively heavy weight.
Brass taps with a reliable universal design are durable, unpretentious for maintenance and can be installed in any position.
Highlights for selecting a device
When choosing a locking mechanism for a gas pipeline, you should pay attention to such characteristics as:
- Pipe diameter. The tap must completely block the flow of gas into the apartment. If the locking element will not fit into the walls gas pipe, then its tightness will be only partial, which can lead to serious consequences.
- Match the diameter and pitch of the thread on the pipe and tap. In this case, the installation of the device is quite easy. The installation of a locking element with a mismatching thread and diameter is possible in principle when using adapters, however, this will require additional material and time costs for the acquisition and installation of additional parts.
- Body integrity. On the outer shell of the element there should be no cracks, chips, sag and other defects. Their presence indicates a violation of the rules of transportation, manufacturing or warehousing of parts, because of which internal malfunctions are possible, as well as a reduction in the period of operation.
You should also pay attention to product quality, giving preference to models of well-known companies.
Step-by-step valve replacement instructions
The procedure for replacing a tap to supply gas to the device is quite simple, but extremely responsible, since natural fuel is combustible, and in combination with air and explosive substances. Therefore, we strongly recommend that you seek the help of specialists who have been trained and have been approved for such work.
To replace the valve on the pipe, you will need tools and materials:
- new locking mechanism suitable for the pipe;
- two gas keys No. 1 or No. 2, one of which is required to unscrew the threads, the second - in order to keep the lower pipe stationary (this will avoid damage to the pipeline leading to the gas stove);
- means intended for sealing the place of attachment of the crane with the pipe (for this purpose you can use ordinary linen thread, FUM tape, Tangit Unilok thread);
- flat screwdriver;
- graphite grease, solid oil or other lubricants;
- a plug for a 0.5-inch pipe with internal thread (when working together, you can do without this element).
If the thread or the diameter of the pipes and the valve do not match, extension cords, fittings, adapters may also be needed.
The replacement process consists of a series of simple operations that must be completed as quickly as possible in order to minimize gas leakage from the system. First of all, it is necessary to shut 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 begin to dismantle the old crane, which is unscrewed from the pipeline. If the process is difficult, you can try to process the threaded connection with the composition WD-40, due to which the ride is increased.
If a welded valve was previously installed in the room, it will have to be cut with a grinder, after which the pipes should be additionally cut. A temporary plug is placed in place of the removed valve.
A thread is screwed onto the thread for sealing. To do this, unscrew about 7 cm of the thread, and put it in the extreme recess of the thread, and then wind the thread clockwise into each hollow.
Having covered the thread with one layer of thread, continue winding in the opposite direction. After that, the laid insulation is covered with a layer of graphite lubricant or other suitable composition.
The plug is removed and a new tap is quickly threaded onto this place (it is important to make sure that its handle is in the “closed” position). The element is screwed on by hand, the last revolutions are carried out with a wrench.
The procedure for calling specialists
The best choice is not to do manipulations with your own hands, but to call Gorgaz employees.
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 to call a specialist (it is better to refrain from using gas before his visit).
- At the appointed time, employees of the company will come to the apartment who will perform diagnostics and decide on the replacement of the crane. They will also tell you which valve model you can purchase yourself or offer to use the option available to him.
- Since Gorgaz specialists may ask you to present them with a gas supply agreement, documents for a gas stove or the last paid gas bills, it is better to prepare them in advance.
- Before the workers' visit, it is also advisable to light blue fuel and let it burn out in the pipe by shutting off its supply by a tap at gas meter. Such an operation will help save time, since all manipulations can be carried out only after emptying the pipeline.
- It is also necessary to well ventilate the room, having a draft.
- When carrying out gas work, it is advisable to be near them in order to control their work.
- After replacing the device, a check should be carried out together with the repairmen, having carried out a trial operation of the burner.
- Specialists fill out the act of the operation, assuring him with the seal of the service organization. The owner of the apartment also signs the paper.
- After completing all the work, the windows should be left open for at least another half hour so that all the gas will erode from the room.
In the case of planned work on the replacement or repair of gas systems, the dismantling of the old locking mechanism and the installation of a new crane model is free of charge, however, the apartment owner acquires the device, as well as consumables at his own expense.
When calling specialists, you will also have to pay a small amount for the service provided and pay for the device.
Revision of the cork crane without replacement
In some cases, it is possible to dispense with valve replacement by cleaning and lubricating the cork device used.
The algorithm of actions in this case is as follows:
- First of all, you need to close the tap by installing its handle perpendicular to the pipe on which it is located.
- Using one of the gas keys, fix the flare in the valve area, further trying to keep it stationary.
- Using a second wrench, drive the coupling and lock nut onto a long thread.
- Try to unscrew the valve with a key, and then, with free rotation, unscrew it to the end manually.
- After removing the part, cover the formed holes with a cap. You should not be afraid of high pressure, since the pressure in the pipe is only 3-5% higher than atmospheric.
- Push the plug onto the thread, then tighten it to the end without tools.
- Unscrew the valve from the drive, removing deposits of old insulating materials and paint.
- Unscrew the plug with the groove on the back of the valve with a screwdriver, taking out the spring hidden under it, and then remove the conical plug from the housing.
- Thoroughly clean the parts (cork, housing) of the remaining old grease, and then apply a new composition to the element.
- After that, collect all the details of the gas valve in the sequence opposite to the algorithm described above.
- Remove the plug and place the assembled part instead, after replacing the insulating materials on the thread.
- Screw in the bend and insulate the thread, then put the locknut and coupling in working position.
In all cases, upon completion of the replacement of the crane, it is necessary to check the correct assembly, and then invite specialists.
Verification of the result of actions taken
After completing all the procedures for replacing the locking mechanism, it is necessary to check the tightness of the created joints. To do this, it is enough to apply the proven method: dilute the soap with water and apply the resulting emulsion to the valve’s seat on the thread, as well as on the cork. If the joints are not firmly connected, bubbles will be observed at the points of gas leakage.
In this case, the defect must be repaired immediately. To do this, remove the tap and repeat all operations again, trying to wind the thread and apply sealant more carefully and accurately.
Work safety rules
All manipulations with gas equipment relate to work with a high level of danger. When performing work on a gas pipeline, a pipe is opened, due to which a gas leak occurs.
This can lead to two serious dangers:
- Natural fuel mixes with air, resulting in an explosive mixture. Any spark that may occur when the appliance is turned on (such as a circuit breaker) can cause an explosion.
- At higher gas concentrations, air becomes unhealthy. Inhalation of the propane-butane mixture causes poisoning of the body, which can even lead to death.
To avoid emergency situations, you must strictly observe safety precautions.
When repairing equipment, in particular, replacing a crane, city gas service employees must comply with the “Rules for technical operation and labor safety requirements in the gas industry of the Russian Federation” (PB 12-368-00 Resolution of the Gosgortekhnadzor of Russia dated 18.07.00 No. 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, so for repairs it is important to have access to the dashboard and machines.
- During manipulations to replace a gas tap in the room, it is forbidden to smoke or light matches.
- All work must be carried out exclusively in the daytime.
- The door to the kitchen where work is carried out must be tightly closed. It is also advisable to plug all the cracks to avoid gas entering other rooms.
- It is forbidden to shut off the valve on a common gas riser, since in this case the gas leak can increase many times, which will increase the risk of explosion.
- It is desirable to carry out all the work together: this will speed up the process and avoid complications.
- Do not self-replace the valve if signs of corrosion or other damage are observed on the gas pipe, in which case it is preferable to call a specialist.
When carrying out work, it is advisable to have a fire fighting device (fire extinguisher) in the immediate vicinity.
Note that the valve for shutting off the gas supply can only be installed on a hard pipe section. If the metal branch near the appliance is damaged, it is transferred. In this case, include gas hose, which is considered a workaround.
Analysis of typical installation errors
Although the operation to replace the gas valve is quite simple, inexperienced craftsmen it may fail.
Typical weaknesses are:
- Inability to connect a tap with a pipe. Most often it happens due to the fact that these elements do not correspond in size or thread. Adapters and extension cords of different shapes and sizes will help to fix the situation. In order not to fall into a similar situation, it is advisable to take into account the parameters of the pipes at the stage of selecting the crane.
- Valve Short. Fasten the thread manually, but use a wrench at the end. If this is not done, the connection will not be reliable enough, which will lead to gas leakage and instability of the structure.
- Tighten the tap exclusively with a wrench. When using the tool, the possibility of damage to the part or thread breakage increases.
- Insufficient tightness of the connection. If checking the replaced faucet indicates that natural gas is entering the air, immediately turn off the stove and correct the error as described above.
Do not use taps 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 requiring a minimum of maintenance with maximum efficiency and durability.
Silicone and other similar materials dry out, lose their elasticity, as a result of which they begin to pass gas. To avoid this, it is better to use graphite-based lubricants.
Conclusions and useful video on the topic
The video shows in detail the process of replacing a valve on a pipe leading to a gas stove:
Replacing a crane is a simple but very responsible process. Even if you have experience in carrying out similar work, according to the standards, you cannot do it yourself - you need to contact specialized services. There are employees who have been trained and have received the necessary clearance for the repair of gas systems.
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