For a heating system to be reliable and energy efficient, it is not enough to carry out high-quality design and installation. It is important to timely and correctly carry out commissioning work, which includes pressure testing of the heating system and its flushing. The mandatory technical control procedure is carried out upon completion of the installation of a new heating system, at the beginning of the heating season and after repair work. In apartment buildings, such work is performed by competent organizations. In a private house, the performance of the heating system can be checked independently. This will require special equipment and knowledge of the requirements of regulatory enactments that regulate the maximum pressure for the system and the time interval for testing different heating networks.
Features of the test
Pressure testing of heating pipes is the final stage after the installation of a new or repair of an existing system before signing an act of work performed.
The procedure involves testing by pumping air or liquid into pipes at a standard pressure, which exceeds the working pressure by several times. For a private house, a check is performed in this way:
- underfloor heating contours;
- heating radiators;
- collectors;
- locking fittings;
- points of connection of pipes to equipment;
- circulation pumps;
- boilers;
- boilers.
This test clearly demonstrates the quality of the material used and shows whether the selected equipment and pipes can withstand high pressures while maintaining tightness at the connection points. With a positive test result, the heating can be started in normal mode without fear of emergencies.
According to the rules, the crimping of the heating system is carried out in a positive temperature outside. Indoors, the air temperature should not be lower than 5 degrees. At negative temperatures, pressure testing is carried out only in emergency cases.
SNiP 41-01-2003 requirements
The requirements of this regulatory document state that indoor hydraulic tests must be carried out in conditions of positive air temperature. Water systems must withstand a pressure of at least 0.6 MPa, without collapsing and without losing tightness.
During the test activities, the pressure should not exceed the limit value established for the pipeline, fittings and heating devices.
When performing hydraulic pressure testing, water is pumped into the pipeline and, using special equipment, a hydraulic pressure is created that exceeds the standard indicator by 1.5-2 times. In this state, the system is left for the required time, during which monitoring is performed in order to detect leaks. When checking plastic pipes, they first hold the working pressure for 2 hours, and in the third hour, the pressure is increased by 30%.
The maximum pressure indicator during hydraulic pressure testing of the heating system and radiators is 10 bar, provided that the tested elements are initially designed for this pressure.
SNiP requirements 3.05.01–85
The requirements of this regulatory document indicate that the pressure testing of the heating unit of the water heating system is performed using the hydraulic method, increasing the pressure by 1.5 times of the operating value. Within 5 minutes, the tested area must withstand such pressure without compromising the integrity and formation of leaks - this means that it has passed the test and is ready for normal operation.
Conditions for performing pressure testing
Heating pressure testing was performed correctly and in full, if all the conditions were met during its implementation:
- During the tests, it is not allowed to carry out other work on the object.
- If the heating system and radiators are pressure tested by a specialist company, they should proceed according to the plan agreed by the lead engineer. The instruction should contain information about the upcoming work, their sequence and the equipment used.
- The presence of other persons, except for specialists conducting tests at the facility, its switching on and off, is not allowed.
- If any work is carried out simultaneously with tests on adjacent objects, it is important to ensure the safety of their performance.
A visual assessment of the operation of heating devices in the process of checking them should be carried out only under operating pressure conditions. At the end of the work, an act is drawn up confirming the tightness of the heating system.
Types of tests and their time
Tests for tightness of the heating unit are carried out in the following situations:
- In a private house, the initial check of the system is carried out at the stage of preparing the house for commissioning. Diagnostics of the pipeline in the grooves and contours of the warm floor is carried out before sealing and pouring the screed. When the mortar is completely dry, it is recommended to carry out additional hydraulic tests to identify and eliminate possible leaks before laying the expensive finishing material.
- To prepare the heat supply network for unscheduled switching on, a periodic hydraulic test is carried out once a year after the end of the heating season. Also, the check is carried out immediately before the start of the heating season at positive ambient temperatures.
- One-time extraordinary checks of the strength and tightness of the system follow immediately after the end of scheduled and unscheduled repair activities.
All of the above measures are of a diagnostic nature and make it possible to timely determine the malfunctions of the heating system leading to its shutdown and repair.
Crimping process
The pressure used in the heating system is selected depending on its purpose and type of equipment. For crimping the input nodes, a pressure of 16 atm is used, for the heating system of a multi-storey building - 10 atm, for a private house - 2-6 atm.
When pressure testing, the deterioration of the building and the heating system should be taken into account. In new buildings, the check is carried out with an excess of pressure by 1.5 - 2 times, and in dilapidated houses no more than 1.5. If the radiators are made of cast iron, during the test, the pressure cannot exceed the limit of 6 atm. For convectors, this value is 10 atm.
The decisive criterion when choosing a pressure in the process of checking the system is the parameters reflected in the technical passport of the equipment. The "weakest" part of the system is taken as a reference point.
Sequence of work
Pressing takes place according to a single algorithm, which looks as follows:
- If work is carried out in a private house with autonomous heating, the boiler is turned off. Turn off the section of the heating system to be checked.
- Drain off the water.
- The pipeline is filled with water, the temperature of which does not exceed 45 degrees. While filling is in progress, air is vented from the system.
- Special equipment is connected to the system - a heating pressure operator, with the help of which the pressure is pumped up to the operating indicator. In this case, a visual inspection of the area under test is carried out.
- Gradually increase the pressure to the value specified in the test plan. Perform a visual inspection of the system for leaks and damage.
- The resulting value is recorded for 10 minutes using a pressure gauge. The readings are recorded. If it remains unchanged, then the system is sealed and ready for use.
The pneumatic test method is used if the hydraulic method cannot be used. For example, at sub-zero temperatures. The indications of the pressure gauge serve as a guideline when detecting a violation of the tightness of the pipeline. Potential leaks are identified by treating them with soapy water.
Allowable test pressure
According to regulatory documents, the pressure during testing for tightness of heating equipment should be:
- for hot water supply and heating systems with a water heater - 10 atm;
- with convector heating - 10 atm;
- for cast iron and steel radiators - 6 atm.
The following indicates that the equipment has successfully passed the tests:
- during the tests, no fogging of heating equipment was found - boilers, pipes, radiators, valves and seams;
- within 5 minutes, the pressure inside the circuit has dropped by no more than 0.2 bar;
- within 10 minutes in a hot water supply system consisting of metal pipes, the pressure drop did not exceed 0.5 bar;
- if the pipes are plastic, it is normal for the pressure to drop to 0.6 bar during the first 30 minutes, and to 0.2 bar during the next 2 hours;
- when conducting air tests on steam heating, the pressure must drop by no more than 0.1 bar in the first 5 minutes.
When testing the DHW system, 5 atm can be added to the operating pressure. When choosing a pressure exceeding the working indicator, the data in the equipment passport are taken into account.
Types of test pumps
Test activities are performed using manual or electric pressure pumps.
Manual models are equipped with pressure control devices, a valve to cut off the incoming water and a shut-off valve to drain water from a rectangular cuvette. A plunger pump is used to pump water under pressure. The main disadvantage of hand-held equipment is the low pumping speed and laboriousness of the process.
The best choice would be electrical equipment. Its advantage lies in the high speed of filling the circuits and in the automatic shutdown when the required pressure is reached.
