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So that the heating system does not fail at the most stressful moment, the heating season passes without problems, it is necessary to periodically check the condition of the equipment, identify all worn parts. Such a check is called “pressure testing of the heating system”, it is carried out according to certain rules.
What is pressure testing of a heating and water supply system
Heating and water supply are two systems consisting of a large number of the most diverse equipment. As you know, the performance of any multicomponent system is determined by the weakest element – when it fails, it stops completely or partially. To identify all weaknesses, pressure testing of heating and water supply is carried out. In simple terms, the pressure is specially raised much higher than the working one, pumping liquid. They do this with the help of special equipment, control the pressure with a pressure gauge. The second name for pressure testing is hydraulic testing. It’s probably understandable why.
When pressure testing of the heating system is carried out, the pressure is raised by 25-80%, depending on the type of pipes, radiators, and other equipment. It is clear that such a test reveals all weak points – everything that does not have a margin of safety breaks, leaks appear in worn pipes and unreliable connections. Having eliminated all the identified problems, we ensure the operability of our heating or water supply for a while.
If we are talking about centralized heating, then pressure testing is usually carried out immediately after the end of the season. In this case, there is a decent period of time for repairs. But this is not the only case when such events are held. Crimping still takes place after repair, replacement of any element. In principle, this is understandable – you need to check how reliable the new equipment and connections are. For example, you soldered heating from polypropylene pipes. It is necessary to check how good the connections turned out. This can be done by pressing.
If we talk about autonomous systems in private houses or apartments, then a new or repaired water supply is usually checked simply by starting the water, although even here a strength test will not hurt. But it is desirable to test the heating “to the full”, both before commissioning and after repair. Keep in mind that those pipelines that are hidden in walls, in the floor or under a suspended ceiling must be tested before they are closed. Otherwise, if during testing it turns out that there are leaks, you will have to disassemble / break everything and fix the problems. Few people will be happy about it.
Equipment and testing frequency
Crimping of centralized systems is carried out by personnel using standard tools, so it is hardly worth talking about it. But not everyone knows for sure what private heating and water supply are experiencing. These are special pumps. There are two types – manual and electric (automatic). Manual crimping pumps are autonomous, the pressure is pumped using a lever, they control the pressure created by the manometer built into the device. Such pumps can be used for small systems – pumping is quite difficult.
Electric crimping pumps are more complex and expensive equipment. They usually have the ability to create a certain pressure. It is set by the operator, and it is “caught up” automatically. Such equipment is bought by firms engaged in crimping professionally.
According to SNiP, hydraulic testing of heating systems should be carried out annually, before the start of the heating season. This applies to private houses too, but few people fulfill this norm. Check at best, every 5-7 years. If you are not going to test your heating every year, then there is no point in buying a pressure tester. The cheapest manual costs about $150, and a good one starts at $250. In principle, you can rent it (usually available in companies selling components for heating systems or in offices for renting equipment). The amount will be small – you need a device for a few hours. So this is a good way out.
Call the experts or do it yourself
If for some purpose you need an act of pressure testing of a heating or hot water supply system, you have only one way out – to order this service from a specialized organization. The cost of pressure testing of heating can be announced to you only individually. It depends on the volume of the system, its structure, the presence of shut-off valves and their condition. In general, they consider the cost based on the tariff for 1 hour of work, and it ranges from 1000 rubles / hour to 2500 rubles / hour. You will have to call various organizations and ask them.
If you have upgraded the heating or hot water supply of your own home, and you know for sure that your pipes and equipment are in good condition, they do not contain salts and deposits, you can carry out pressure testing yourself. No one will demand acts of hydraulic testing from you. Even if you see that your pipes and radiators are clogged, you can flush everything yourself, and then test again. If you just do not want to do this, you can call specialists. They will immediately clean the system and carry out pressure testing, and even give you an act.
Crimping process
Pressure testing of heating systems of a private house begins with disconnecting the heating boiler, automatic air vents and expansion tank from the system. If shut-off valves lead to this equipment, you can close them, but if the valves turn out to be faulty, the expansion tank will definitely fail, and the boiler, depending on the pressure that you apply to it. Therefore, it is better to remove the expansion tank, especially since this is not difficult to do, but in the case of the boiler, you will have to rely on the serviceability of the taps. If there are thermostats on the radiators, it is also advisable to remove them – they are not designed for high pressure.
Sometimes not all heating is tested, but only some part. If possible, it is cut off with the help of shut-off valves or temporary jumpers are installed – spurs.
There are two important points: pressure testing can be carried out at an air temperature not lower than +5°C, the system is filled with water at a temperature not higher than +45°C.
Further, the process is as follows:
- If the system was in operation, the coolant is drained.
- A pressurizer is connected to the system. A hose extends from it, ending with a union nut. This hose is connected to the system in any suitable place, even in place of the removed expansion tank or instead of a drain cock.
- Water is poured into the capacity of the pressure test pump, and pumped into the system with the help of a pump.
The device is connected to any available input – on the supply or return pipeline – it does not matter - Remove all air from the system before pressurizing. To do this, you can pump the system a little with the drain valve open or lower it through the air vents on the radiators (Mayevsky taps).
- The system is brought to operating pressure, maintained for at least 10 minutes. During this time, all the remaining air descends.
- The pressure rises to the test pressure, a certain period of time is maintained (regulated by the regulations of the Ministry of Energy). During the test, all devices and connections are checked. They are inspected for leaks. Moreover, even a slightly wet connection is considered a leak (fogging also needs to be eliminated).
- During crimping, the pressure level is controlled. If during the test its drop does not exceed the norm (written in SNiP), the system is considered to be in good order. If the pressure drops even slightly below normal, you need to look for a leak, fix it, then start pressure testing again.
As already mentioned, the test pressure depends on the type of equipment and system being tested (heating or hot water). The recommendations of the Ministry of Energy set forth in the “Rules for the technical operation of thermal power plants” (clause 9.2.13) are summarized in a table for ease of use.
| Type of equipment tested | Test pressure | Test duration | Permissible pressure drop |
|---|---|---|---|
| Elevator units, water heaters | 1 MPa(10 kgf/cm2) | 5 minutes | 0,02 MPa (0,2 kgf / cm2) |
| Systems with cast iron radiators | 0,6 MPa (6 kgf / cm2) | 5 minutes | 0,02 MPa (0,2 kgf / cm2) |
| Systems with panel and convector radiators | 1 MPa (10 kgf / cm2) | 15 minutes | 0,01 MPa (0,1 kgf / cm2) |
| Hot water supply systems from metal pipes | working pressure + 0,5 MPa (5 kgf/cm2), but not more than 1 MPa (10 kgf/cm2) | 10 minutes | 0,05 MPa (0,5 kgf / cm2) |
| Hot water systems from plastic pipes | working pressure + 0,5 MPa (5 kgf/cm2), but not more than 1 MPa (10 kgf/cm2) | 30 minutes | 0,06 MPa (0,6 kgf/cm2), with a further check within 2 hours and a maximum drop of 0,02 MPa (0,2 kgf/cm2) |
Please note that for testing heating and plumbing from plastic pipes, the holding time of the test pressure is 30 minutes. If during this time no deviations are found, the system is considered to have successfully passed the pressure test. But the test continues for another 2 hours. And during this time, the pressure drop in the system should not exceed the norm – 0,02 MPa (0,2 kgf / cm2).
On the other hand, SNIP 3.05.01-85 (clause 4.6) has other recommendations:
- Tests of heating and water supply systems should be carried out with a pressure of 1,5 from the working one, but not lower than 0,2 MPa (2 kgf / cm2).
- The system is considered serviceable if after 5 minutes the pressure drop does not exceed 0,02 MPa (0,2 kgf/cm).
Which rules to use is an interesting question. While both documents are in force and there is no certainty, so both are eligible. It is necessary to approach each case individually, taking into account the maximum pressure for which its elements are designed. So the working pressure of cast-iron radiators is no more than 6 atm, respectively, the test pressure will be 9-10 atm. Approximately also it is necessary to be determined with all other components.
Air pressure testing
Not everywhere and not always there is an opportunity to rent a pressure tester, as well as to buy it. For example, you need to test the heating in the country. The equipment is specific and the chances that acquaintances have it are very small. In this case, the heating system is pressurized with air. To pump it, you can use any compressor, even an automobile one. The pressure is monitored by a connected pressure gauge.
Such crimping is less convenient and not entirely correct. Heating and plumbing are designed to transport liquids, and they are much denser than air. Where water won’t even ooze, air will come out. Therefore, with a high degree of certainty, we can say that you will have an air leak – somewhere there is a loose connection. Moreover, it is difficult to determine the place of leakage during such testing. For this, a soapy solution is used, with which all joints and joints are smeared, all places where air can escape. Bubbles appear at the leak. Sometimes it takes a long time to find. That is why such pressure testing of the heating system is not very popular.
Crimping a warm floor has its own characteristics – you must first check the comb and all the devices attached to it. To do this, close all the supply and return valves of the loops, filling only the underfloor heating collector, check it by raising the pressure. Having dropped it to normal, the loops of the warm floor are filled in turn, and only then excess pressure is created. The process is described in more detail in the video.