Gas is supplied to the end consumer in apartments and houses through a distribution network. Transportation is carried out through pipes for which certain GOST standards have been established. The same standards establish the service life of gas pipes in residential buildings for their various types.
After the expiration of the operating period laid down by the manufacturer, a major replacement of the gas pipeline must be carried out. This should be monitored by specialized control services, however, it will not be superfluous for consumers to know how much pipes should be used, how to determine the degree of their wear and the need for replacement.
The content of the article:
- What does service life mean?
- Legal and regulatory framework: what does the Law say?
- What factors affect the condition of gas pipes?
- What are the criteria for determining the need for replacement?
- What to do if the service life of the gas pipeline has expired?
- What to do to extend the operational life?
- How to calculate wear rate?
- Conclusions and useful video on the topic
What does service life mean?
Life time – this is the calendar duration of the period of use of the highways and branches connected to them of the gas pipeline from the beginning of the commissioning of the system or after its repair to the transition to the limit condition. Defined by its manufacturer gas pipes, as indicated in the certificate.
As such, there is no universal life limit. In each specific case, it is determined individually, since one gas pipeline is operated in favorable conditions, and the other is deformed and destroyed much faster due to the influence of external factors.
Legal and regulatory framework: what does the Law say?
According to the Order of November 21, 2013 No. N 558, which regulates safety rules when handling liquefied gas.
The maximum service life of pipes is determined by the manufacturer, but it can be extended several times if the technical condition of the pipe products allows.
The technical inspection of the underground gas pipeline is carried out upon the expiration of the estimated service life, which is for:
- steel pipes - 40 years;
- polyethylene pipes - 50 years.
Pipelines assembled from polymer pipes last longer due to their higher resistance to mechanical and chemical influences, as well as the lack of prerequisites for the appearance and settlement mold.
In this case, during such a diagnosis, the following parameters should be checked:
- tightness of the gas pipeline;
- protective coating (for steel pipes);
- the state of the material from which the gas pipeline is made;
- quality of welding at the joints.
Early inspections are carried out only in case of accidents or obtaining reliable information about the deformation of gas pipelines underground.
The gas pipeline is checked at the end of the system's service life, but if an accident occurs, specialists go to the scene of the incident right there to check the tightness of the system
Surveys are still carried out in accordance with the instruction with RD 204 RSFSR 3.3-87, approved back in 1987. The provisions contained in the Decree of the Government of the Russian Federation of October 29, 2010 No. N 870, in relation to this issue, contain rather vague wording.
So, in clause 76 it is said that the operational period is determined at the time of design, taking into account the conditions for ensuring safety of facilities, forecast regarding changes in their parameters, as well as guarantees for pipe products, which are given by manufacturer.
In addition, this act states that the gas pipeline can be operated even after the expiration service life, if the diagnostics did not reveal any serious irregularities in the operation of the system and defects in the pipes. Based on the results of such diagnostics, the service life limits should be re-established.
Concerning external gas pipelines and equipment, as a rule, their service life is shorter. In any case, you should always pay attention to their work experience, which is indicated by the manufacturer.
For example, the manufacturer Gazovik defines the following terms for GRPSh-6, 10 and 10MS:
- medium (before write-off) - 15 years;
- warranty term - 5 years.
But the "First Gas Company" in the passports for most of its GRPS indicates a 20-year period, which, by the way, is the average for GRPS installations.
What factors affect the condition of gas pipes?
As the experience of leading expert Russian organizations shows, underground steel gas pipelines retain their physical and mechanical properties even after forty years of service. Welded joints are also within regulatory limits and therefore extend their life.
But this does not happen with respect to all pipes, and yet not always, so you need to figure out what determines the state of pipes with the same characteristics over time.
One of the reasons for the short service life of a gas pipeline may be poor-quality performance of work on its installation at the initial stage.
The actual state of the pipeline and the time it will reach its limit state depends on:
- the correctness of engineering decisions taken at the time of design;
- the conscientiousness of the construction and installation work;
- the quality of the materials used in the construction;
- the level of corrosiveness of the soil;
- the effectiveness of electrochemical protection;
- monitoring;
- the regularity and quality of the repairs carried out, etc.
That is why pipes produced from the same plant with the same operating parameters can show themselves in different ways in operation over time.
What are the criteria for determining the need for replacement?
Above were indicated conditional standard operating periods. They are "cut off" from reality and are exemplary. In some cases, a gas pipeline may fail earlier, or it may last much longer than the average service life of gas pipes in industrial and residential buildings, industrial facilities.
In practice, the service life of a gas pipeline made of steel pipes is on average 30 years.
Only a GorGaz employee can correctly assess the condition of the pipeline and gas equipment
It is also worth noting that it will not be possible to determine the state of steel structures "by eye" by external signs. Utility workers must carry out appropriate examinations and measurements.
The signs by which it is possible to determine that the gas pipeline needs pipe replacement are:
- thinning of the walls above the norm;
- changes in the nature of the joints at the welding points;
- gas leak according to meter readings.
Their results are reflected in the protocols, which the consumer has the right to familiarize himself with. In addition, he may require an oral explanation of the material presented.
What to do if the service life of the gas pipeline has expired?
In the event of the expiration of their service life, their repair should be carried out, which provides for a full or partial replacement of elements.
If a check has already been carried out by the competent persons and they have come to the conclusion that replacement needed, the consumer does not need to do anything. Repair work should be carried out by employees of GorGaz or other similar services serving the facility.
Each consumer must be familiar with the rules for operating the gas pipeline, as well as be able to shut off the gas supply to the apartment if necessary
To completely replace the gas pipeline, an on-site team is sent to the site, which removes the failed sections main passage to the common building complex of pipes, and then - looks at the situation.
Partial replacement of pipes in a multi-storey building is carried out by cutting off old sections and placing new ones by welding.
Such events are carried out strictly in accordance with safety rules:
- Gas access to pipes is blocked.
- From the site that will be replaced, gas must be completely removed in accordance with the rules of safe handling in relation to hazardous facilities.
- The old section is cut off.
- By welding, a new element is mounted in its place.
- The site is being checked for integrity and tightness.
- Starting the gas flow through the pipe after they have been purged.
Gas equipment cannot be repaired by yourself. This is a complex and dangerous process that can only be carried out by gas workers with the necessary equipment.
Moreover, the fact that such work was carried out, as well as the date of their implementation, it is necessary to enter information in the data sheet, in which all actions carried out with the system are noted. This is necessary in order to subsequently be able to determine the service life of the new gas pipeline.
To prolong the service life of the internal gas pipeline, operate it according to the regulations. For example, do not bend the hose that supplies gas from the system to the stove.
If the consumer has suspicions that the pipes have become unusable, he can make an application to the appropriate utility services and expect the arrival of their employees, but in no case should you check your version without their presence.
What to do to extend the operational life?
In fact, how long the gas pipeline will last depends, among other things, on the consumer.
To extend the term of its work, it is necessary to systematically follow simple rules:
- Rule # 1. Timely inspection and inspection of pipes. To do this, it is necessary to let the inspectors in and try to stay at home if the time of the inspection is announced in advance.
- Rule # 2. Switching on the equipment in the correct sequence. Carrying out gas system pressure testing according to the instructions and safety rules. The consumer must know which valve is responsible for what. If you are not aware of this, it is better to consult the gas workers who serve your home.
- Rule # 3. Urgent check for suspected gas leaks. You should call the gas service immediately. They are obliged to promptly leave at the specified address. Before their arrival, it is better to turn off the gas valve in the apartment.
You can check the leak yourself as follows: in pipe sections where the smell of gas is especially felt, anoint a suspicious place with soapy foam. If bubbles begin to swell in the area, there is most likely a leak.
However, this is not a 100% leak detection method, let alone a professional one. But for domestic use, in the absence of professional equipment, it is quite suitable and, as practice shows, is quite effective.
To check for a gas leak, coat the valve and welds with soapy foam.
If the above describes what needs to be done in order to extend the service life and normal operation of internal gas pipelines, then below it is said about what to do the other way around:
- tie / wrap pipes with ropes;
- reinstall equipment / change gas pipeline sections independently;
- check for leaks with open flame sources (lighters or matches);
- deform (twist / bend) the hoses connecting the system to the stove.
Compliance with these rules is necessary not only in order to extend the "life" of your gas pipes, but also to eliminate the risks of dangerous situations.
How to calculate wear rate?
For this, complex technical calculations are carried out.
Calculations are performed to obtain the following characteristics:
- design stress σs;
- SDR pipes;
- wall thickness.
After that, the minimum long-term strength MRS * of the material from which the pipe is made by a safety factor (for calculating pipelines) C.
Conclusions and useful video on the topic
For calculations, the strength is taken, determined at a temperature of 20 ° C for a service life of 50 years according to ISO 9080:
Compliance with the terms stipulated by building codes and guaranteed by the manufacturer is necessary to ensure the safe operation and operation of the system. Checking the technical condition of the gas supply related to the category of explosive communications is a necessary measure. It will save you from risks and a lot of problems.
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