Hydraulic testing of water supply and heating systems. Why are hydraulic testing of pipelines needed? Private houses: we carry out pressure testing

8.1 According to SNiP 3.05.04, pressure and non-pressure water supply and sewerage pipelines are tested for strength and density (tightness) by hydraulic or pneumatic methods twice (preliminary and final).

8.2 Preliminary test (excessive) hydraulic pressure during strength testing, performed before backfilling the trench and installing fittings (hydrants, safety valves, plungers), must be equal to the design operating pressure multiplied by a factor of 1.5.

8.3 The final test hydraulic pressure for density tests performed after backfilling the trench and completion of all work on this section of the pipeline, but before installing hydrants, safety valves and plungers, in place of which plugs are installed during the test, must be equal to the design working pressure multiplied by coefficient 1.3.

8.4 Before testing pressure pipelines with socket connections with O-rings, temporary or permanent stops must be installed at the ends of the pipeline and at the bends.

8.5 Preliminary hydraulic testing of pressure pipelines should be carried out in the following order:

Fill the pipeline with water and keep it without pressure for 2 hours;

Create test pressure in the pipeline and maintain it for 0.5 hours;

Reduce the test pressure to the design pressure and inspect the pipeline.

The pipeline is kept under operating pressure for at least 0.5 hours. Due to deformation of the pipeline shell, it is necessary to maintain test or operating pressure in the pipeline by pumping water until complete stabilization.

The pipeline is considered to have passed the preliminary hydraulic test if no ruptures of pipes or joints and connecting parts are detected under test pressure, and no visible water leaks are detected under operating pressure.

8.6 The final hydraulic test for density is carried out in the following order:

A pressure should be created in the pipeline equal to the design operating pressure and maintained for 2 hours; when the pressure drops by 0.02 MPa, water is pumped;

The pressure is raised to the test level within a period of no more than 10 minutes and maintained for 2 hours.

The pipeline is considered to have passed the final hydraulic test if the actual leakage of water from the pipeline at the test pressure does not exceed the values ​​​​specified in Table 5.

8.7 Hydraulic testing of gravity sewer networks is carried out after completion of waterproofing work in wells in two stages: without wells (preliminary) and together with wells (final).

8.8 The final test of the sewerage pipeline together with the wells is carried out in accordance with SNiP 3.05.04.

8.9 Hydraulic tests of systems made of polymeric materials of internal pipelines are carried out at positive ambient temperatures no earlier than 24 hours after the last welded and adhesive joint is made.

8.10 Hydraulic testing of internal drainage systems is carried out by filling them with water to the full height of the risers. Tests are carried out after external inspection of pipelines and elimination of visible defects. Hydraulic testing of glued pipelines begins no earlier than 24 hours after the last connection. The drainage system is considered to have passed the test if, 20 minutes after its filling, an external inspection of the pipelines reveals no leaks or other defects and the water level in the risers has not decreased.

8.11 Pneumatic tests of pipelines made of polymer materials are carried out during ground and above-ground installation in the following cases: ambient air temperature below 0 ° C; the use of water is unacceptable for technical reasons; There is no water in the quantity required for testing.

The procedure for pneumatic testing of pipelines made of polymeric materials and safety requirements during testing are established by the project.

8.12 Preliminary and final tests of gravity sewer networks made of large-diameter pipes may be carried out pneumatically. Preliminary tests are carried out before the final filling of the trench (welded joints are not covered with soil). A test pressure of compressed air equal to 0.05 MPa is maintained in the pipeline for 15 minutes. At the same time, welded, glued and other joints are inspected and leaks are detected by the sound of leaking air, by bubbles formed in places of air leakage through butt joints coated with soap emulsion.

Final pneumatic tests are carried out when the groundwater level above the pipe in the middle of the pipeline under test is less than 2.5 m. Final pneumatic tests are carried out on sections 20-100 m long, and the difference between the highest and lowest points of the pipeline should not exceed 2.5 m. Pneumatic tests are carried out 48 hours after backfilling the pipeline. The test excess pressure of compressed air is indicated in Table 6.

8.13 Acceptance of pipelines for operation must be carried out in accordance with the basic provisions of SNiP 3.01.04, as well as SNiP 3.05.04. When testing water supply and pressure sewerage pipelines and putting them into operation, the following must be drawn up:

Acts for hidden work (on the base, supports and building structures on pipelines, etc.);

Acts of external inspection of pipelines and elements (units, wells, etc.);

Test reports for the strength and density of pipelines;

Certificates for washing and disinfection of water pipelines;

Establishing compliance of the work performed with the project;

Certificates of incoming quality control of pipes and connecting parts.

8.14 In addition to the acceptance of hidden work and verification of pipeline testing reports for density and external inspection, the acceptance of non-pressure pipelines must be accompanied by a straightness check, as well as an instrumental check of trays in wells.

When accepting internal water pipelines, passports or certificates for polymer pipes, connecting parts and fittings are additionally checked.

Before commissioning, after all installation and repair work has been completed, water supply systems are tested using the hydrostatic or manometric method in compliance with the requirements of GOST 24054-80, GOST 25136-82 and SNiP 3.01.01-85. A pressure gauge with an accuracy class of at least 1.5 and a hydraulic press are connected to the control drain valve to create pressure in the system. The internal network is filled with water, all shut-off valves are opened, all leaks are eliminated and air is removed through the highest water points. After performing these operations, the pressure rises to the required value. Cold and hot water supply networks are tested at a pressure exceeding the operating pressure by 0.5 MPa (5 kgf/cm2), but not more than 1 MPa (10 kgf/cm2) for 10 minutes; In this case, a decrease in pressure is allowed by no more than 0.1 MPa (1 kgf/cm2).

Hydrostatic and manometric tests of cold and hot water supply systems are carried out before installing water fittings.

Systems are considered to have passed the tests if, within 10 minutes of being under test pressure using the hydrostatic method, no pressure drop of more than 0.05 MPa (0.5 kgf/cm 2) and drops were detected in welds, pipes, threaded connections, fittings, as well as water leaks through flush devices. At the end of the hydrostatic test, it is necessary to release water from the internal cold and hot water supply systems.

Manometric tests of the internal cold and hot water supply system are carried out in the following sequence: the system is filled with air at a test excess pressure of 0.15 MPa (1.5 kgf/cm 2); if installation defects are detected by ear, the pressure should be reduced to atmospheric pressure and the defects eliminated; then fill the system with air at a pressure of 0.1 MPa (1 kgf/cm2), hold it under test pressure for 5 minutes. The system is considered to have passed the test if, when it is under test pressure, the pressure drop does not exceed 0.01 MPa (0.1 kgf/cm2).

In cases where it is difficult to carry out hydrostatic tests, a manometric test is carried out.

The testing of the system is documented in a document. To accept the system into operation, the following basic documents are presented:

– acts, drawings and approval documents for additional work and changes made during installation work;

– acts for hidden work;

– test reports for individual elements (assemblies, devices, equipment) with all passports attached;

– test reports for network tightness and equipment operating efficiency (pumps, tanks, fire hydrants, etc.).

The acceptance certificates indicate all noted defects and malfunctions, deviations from the approved project, test results of equipment and the system as a whole, the quality of the work performed, the presence of deficiencies, and the deadline for their elimination.

In the hot water supply system, its effectiveness is checked - provision of design temperatures, heating of heated towel rails in circulation mode, operation of water heaters and circulation pumps.

All documentation for testing systems and the main acceptance certificate with an assessment of installation work are transferred to the building maintenance service.

When operating cold and hot water supply systems, the flow of cold and hot water must be ensured based on established standards

CONSUMPTION RATES FOR COLD AND HOT WATER CONSUMERS

2.Operational characteristics of the hot water supply system.

The quality of water supplied to the hot water supply systems of a residential building must meet the requirements of GOST and SanPiN. The temperature of water supplied to water points (taps, mixers) must be at least 60°C in open hot water supply systems and at least 50°C in closed ones. The water temperature in the hot water supply system must be maintained using an automatic regulator, the installation of which in the hot water supply system is mandatory. The water temperature at the outlet of the water heater of the hot water supply system is selected from the condition of ensuring the normalized temperature at the water distribution points, but not more than 75°C.

Engineering and technical workers and workers servicing the hot water supply system are required to:

Study the system in situ and from drawings;

Ensure proper operation of the system by eliminating identified deficiencies;

Instruct residents of serviced buildings about the need to timely report leaks and noise in water supply fittings, and to use hot water economically;

Monitor compliance with these requirements.

The pressure in the hot water supply system is maintained at 0.05-0.07 MPa (0.5-0.7 kgf/cm2) above the static pressure. Water heaters and pipelines must be constantly filled with water. The main gates and valves designed to shut off and regulate the hot water supply system must be opened and closed 2 times a month. Opening and closing of the said fittings is done slowly.

During operation, it is necessary to monitor the absence of leaks in the risers, connections to shut-off and control valves and water taps, and eliminate the causes of their malfunction and water leakage.

Inspection of hot water supply systems is carried out according to a schedule approved by the organization’s service specialists; the results of the inspection are recorded in a journal.

The operation of automatic temperature and pressure regulators of hot water supply systems is checked at least once a month.

To reduce heat loss, it is necessary to insulate the risers of hot water supply systems with effective thermal insulation material.

When operating centralized hot water supply systems, it is prohibited to use control and measuring instruments filled with mercury.

Hot water supplied to the consumer, regardless of the system used and the processing method, must meet the requirements of GOST 2874-82. For anti-scale treatment of water, the use of both chemical (reagent) and physical (reagent-free) methods is allowed. Chemical methods can only be used on heat sources. Physical methods include magnetic water treatment.

3.Operational characteristics of the cold water supply system.

The cold water supply system must withstand pressure up to 1 MPa (10 kgf/cm2).

Organizations servicing cold and hot water supply systems must ensure:

a) carrying out preventive maintenance (inspections, adjustment of systems), scheduled preventative repairs, elimination of major defects in construction and installation work for the installation of water supply systems (installation of sealing sleeves when pipelines cross floors, etc.) within the time limits established by the work plans of maintenance organizations ;

b) elimination of excess noise and vibration in the premises from the operation of water supply systems (hydraulic shocks, high speed of water flow in pipes and when flowing out of the water supply
fittings, etc.), regulation (increase or decrease) of pressure in the water supply system to the standard level within a specified time frame;

c) elimination of leaks, leaks, blockages, blockages, defects due to sedimentary deformations of parts of the building or poor installation of sanitary systems and their shut-off and control valves in a timely manner;

d) preventing the formation of condensation on the surface of water supply pipelines;

e) maintenance of pumping installations of water supply systems;

f) study by plumbers of water supply systems in situ and according to technical (design) documentation (floor plans indicating the types and brands of installed equipment,
instruments and fittings; axonometric diagram of the water supply network indicating the diameters of the pipes and the specification sheet for the installed equipment, water intake and water distribution fittings). In the absence of project documentation, as-built documentation must be drawn up;

g) control over compliance by employers, owners and tenants with the rules for using water supply systems;

h) engineering control over the timely execution of requests from employers to eliminate water supply faults.

The room of the water metering unit must have lighting, and the temperature in it in winter must not be lower than 5 ° C. Currently, pressure plastic pipes are widely used for the installation of cold and hot water supply systems. Their service life in cold water supply systems is 50 years, and in hot water supply systems - 30 years.

This service life is possible if certain requirements are met:

Carrying out tests for resistance to internal hydrostatic pressure at elevated temperatures;

High-quality production of pipes and connecting parts;

Ensuring the quality of installation of pipes between each other and with fittings.

When accepting systems made from plastic pipes into operation, an external inspection is first carried out, which allows you to evaluate the quality of the installation performed.

The rules for operating plastic pipelines in cold and hot water supply systems are similar to the rules for operating these pipelines in drainage systems.

Topic: Basic faults in water supply systems

Objective of the lesson: Identify the causes of the malfunction and determine measures to eliminate them.

Topic questions

1. Equipment used to regulate pressure in the network.

2.Main faults in the water supply system

Related information.

EniR

§ E9-2-9. Pipeline testing

Characteristics of work conditions

Pipeline testing is carried out hydraulically or pneumatically.
Pipelines are tested for strength and tightness, usually hydraulically. Depending on the climatic conditions in the construction area and in the absence of water, a pneumatic testing method can be used for pipelines with an internal design pressure Pр, not exceeding: underground cast iron, asbestos-cement and reinforced concrete - 0.5 MPa (5 kgf/cm2); underground steel - 1.6 MPa (16 kgf/cm2); above-ground steel - 0.3 MPa (3 kgf/cm2).
Testing of pressure pipelines of all classes is carried out, as a rule, in two stages:
first - a preliminary test for strength and tightness is carried out after filling the sinuses with tamping soil to half the vertical diameter and filling the pipes in accordance with the requirements of SNiP III-8-76 "Earth structures" with butt joints left open for inspection, but before closing the channels and installation of stuffing box compensators, sectional valves, hydrants, plungers, safety valves;
second - acceptance (final) test for strength and tightness is carried out after complete backfilling of the pipeline and completion of construction and installation work, installation of all heating network equipment (valves, compensators, etc.) provided for by the trench backfilling project, but before installation of hydrants, plungers, safety valves valves, instead of which flange plugs are installed during testing.
Preliminary testing of pipelines that can be inspected in working condition or that are subject to immediate backfilling during the construction process (work in winter, in cramped conditions), with appropriate justification in the projects, may not be carried out.
Gravity pipelines are tested for leaks twice: preliminary before backfilling and acceptance (final) after backfilling.
The installed gas pipeline is tested for strength and density with air after installing the shut-off valves.

Scope of work

During pneumatic testing of pipelines

1. Cleaning and purging of pipelines.
2. Installation of plugs and pressure gauge.
3. Connecting a compressor or air cylinder to the pipeline.
4. Filling the pipeline with air to a given pressure.
5. Preparation of soap solution. 6. Inspection of the pipeline, smearing the joints with soapy water and marking defective areas.
7. Elimination of detected defects.
8. Secondary testing and delivery of the pipeline.
9. Disconnecting the compressor or cylinder and bleeding air from the pipeline.
10. Removing the plugs and pressure gauge.

During hydraulic testing of pipelines

1. Cleaning of pipelines.
2. Installation of plugs with their fastening with temporary stops, pressure gauge and taps.
3. Connection of water supply and press.
4. Filling the pipeline with water to the specified pressure.
5. Inspection of the pipeline with marking of defective areas.
6. Elimination of detected defects.
7. Secondary testing and delivery of the pipeline.
8. Disconnecting the water supply and draining the water from the pipeline.
9. Removing plugs, stops and pressure gauges.

When flushing pipelines

1. Connecting the water supply.
2. Filling the pipeline with water.
3. Flushing the pipeline until the water is completely clear of turbid impurities.
4. Draining water from the pipeline.
5. Filling the pipeline with chlorine water.
6. Draining chlorine water from the pipeline.
7. Secondary filling and flushing of the pipeline after chlorination.

Table 1

table 2

Time standards and prices for 1 m of pipeline

Notes: 1. Standards table. 2 provides for testing steel, cast iron and asbestos-cement pipelines in sections up to 500 m, and ceramic, concrete and reinforced concrete sections up to 100 m. When testing steel, cast iron and asbestos-cement pipelines in sections of St. 500 m, and ceramic, concrete and reinforced concrete sections of St. 100 m Time standards and prices multiplied by 0.75 (PR-1).
2. When testing pipelines by various sections of workers, for preliminary testing, multiply Time Standards and Prices by 0.6 (PR-2), for final testing by 0.4 (PR-3).
3. When hydraulic testing pipelines using a hand press, multiply time standards and prices by 1.2 (PR-4).
4. The laying of a temporary water supply system should be standardized according to § E9-1-2, Table 2, Note 1.
5. When flushing pipelines without chlorination, multiply the Time Standards and Costs of column “d”: when filling the pipeline twice - by 0.6 (PR-5), when filling the pipeline once - by 0.4 (PR-6).

Carrying out strength tests using the pneumatic method involves filling the pipeline with air or gas at the first stage. Then the pressure increases. When the level rises to 0.6, you can proceed to inspect the area being inspected. This is true for structures in which the operating pressure reaches 2 kgf/cm 2.

During the inspection, the load should be increased. However, tapping surfaces that are under load with a hammer is unacceptable. At the final stage, the system is examined under workloads. Testing the tensile strength of welded joints and seams, flanges and seals involves applying a soap solution.

If the system transports flammable, toxic, toxic substances, then the leak test is complemented by a density test. To do this, the pressure drop is examined in parallel. It is important to check all equipment that is connected to the system. If during the strength test the pressure on the pressure gauge did not decrease, and no sweating or leakage was detected in the seals and connecting seams, then the result is considered satisfactory.

Information about test reports

When tests are carried out by a construction organization or commission, the following documentation is submitted:

• executive scheme;
• design of the test site;
• welding log;
• insulation work journal;

As an additional application, there are certificates for parts and pipes, as well as passports for equipment. The result of testing a separate section is a report.

Based on the results of the leak investigation, the commission draws up a report, accompanied by materials that must contain:

• name of company;
• composition of the commission;
• information about test parameters;
• certificate for a collapsed (defective) pipe;
• information about the pipeline design;
• extract from the welding log;
• elevation mark of the rupture site;
• act of production and acceptance of construction and installation works.

The pipeline strength test report is drawn up taking into account the current regulations. It necessarily involves indicating the composition of the commission, the deadlines for completing the work and the conclusion and signatures of the responsible persons. From these documents you will be able to find out under what parameters the leak test was carried out. This should include not only pressure, but also the total length of the system. The strength testing report for pipelines will contain the names of the devices and other equipment used, as well as the location of their installation and the length of the section from which water was removed after the test.

Conclusion

Pipeline testing and evaluation of results should only be carried out by qualified personnel. They must receive job descriptions and have the appropriate skills. It is important to remember that testing the pipeline for strength and tightness must be carried out in a timely and thorough manner, because this is the only way to avoid accidents, losses and even accidents.

Hydraulic tests are carried out in accordance with SNiP. After their completion, a report is drawn up indicating the operability of the system.

They are performed at different stages of communications operation. Test parameters are calculated for each system separately, depending on its type.

Contents of the article

Why and when to carry out hydraulic tests?

Hydraulic testing is a type of non-destructive testing that is carried out to check the strength and tightness of pipeline systems. All operating equipment is subjected to it at different stages of operation.

In general, three cases can be distinguished in which tests must be carried out without fail, regardless of the purpose of the pipeline:

• after completion of the production process for the production of equipment or parts of the pipeline system;
• after completion of pipeline installation work;
• during operation of the equipment.

Hydraulic testing is an important procedure that confirms or refutes the reliability of the operating pressure system. This is necessary to prevent accidents on highways and preserve the health of citizens.

The procedure for hydraulic testing of pipelines in extreme conditions is being carried out. The pressure under which it passes is called the test pressure. It exceeds the usual operating pressure by 1.25-1.5 times.

Features of hydraulic tests

Test pressure is supplied to the pipeline system smoothly and slowly, so as not to provoke water hammer and accidents. The pressure value is determined not by eye, but by a special formula, but in practice, as a rule, it is 25% more than the working pressure.

The water supply force is controlled on pressure gauges and measurement channels. According to SNiP, jumps in indicators are allowed, since it is possible to quickly measure the temperature of the liquid in a pipeline vessel. When filling it, be sure to monitor the accumulation of gas in different parts of the system.

This possibility should be excluded at the initial stage.

After filling the pipeline, the so-called holding time begins - a period during which the equipment under test is under increased pressure. It is important to ensure that it is at the same level during exposure. After its completion, the pressure is minimized to operating condition.

No one should be near the pipeline while the test is being carried out.

Personnel operating it must wait in a safe place, as testing the system's functionality can be explosive. After the process is completed, the results obtained are assessed in accordance with SNiP. The pipeline is inspected for metal explosions and deformations.

Hydraulic test parameters

When checking the quality of a pipeline, it is necessary to determine the indicators of the following work parameters:

1. Pressure.
2. Temperatures.
3. Holding time.

The lower limit of the test pressure is calculated using the following formula: Ph = KhP. The upper limit should not exceed the sum of the total membrane and bending stresses, which will reach 1.7 [δ]Th. The formula is deciphered as follows:

• P – design pressure, the parameters of which are provided by the manufacturer, or operating pressure if tests are carried out after installation;
• [δ]Th – rated voltage that is allowed at test temperature Th;
• [δ]T – permissible stress at design temperature T;
• Kh is a conditional coefficient that takes different values ​​for different objects. When checking pipelines, it is equal to 1.25.

The water temperature should not fall below 5˚C and not rise above 40˚C. The only exceptions are those cases when the temperature of the hydraulic component is indicated in the technical conditions of the object under study. Be that as it may, the air temperature during the test should not fall below the same 5˚C.

The holding time must be specified in the design documentation for the facility. It should not be less than 5 minutes. If exact parameters are not provided, then the holding time is calculated based on the thickness of the pipeline walls. For example, with a thickness of up to 50 mm, a pressure test lasts at least 10 minutes, with a thickness over 100 mm - at least 30 minutes.

Testing of fire hydrants and water supply lines

A hydrant is equipment responsible for quickly eliminating fire ignitions, so it must always be in working order. The main task of fire hydrants is to provide the optimal amount of water to fight a fire at its initial stage.

Pressure pipelines are checked in accordance with SNiP V III-3-81.

Pipes made of cast iron and asbestos are tested with a pipeline length of no more than 1 km at a time. Polyethylene water supply lines are checked in sections of 0.5 km. All other water supply systems are checked in sections of no more than 1 km. The holding time for metal water supply pipes must be at least 10 m, for polyethylene pipes - at least 30 m.

Heating system testing

Heating networks are checked immediately after their installation is completed. Heating systems are filled with water through the return pipeline, that is, from the bottom up.

With this method, liquid and air flow in the same direction, which, according to the laws of physics, promotes the removal of air masses from the system. Discharge occurs in one way: through outlet devices, a tank or heating system plungers.

If heating networks are filled too quickly, air pockets may occur due to the risers filling with water faster than the heating devices of the heating systems. pass under the lower value of the working pressure of 100 kiloPascal and the test pressure - 300 kiloPascal.

Heating networks are checked only when the boiler and expansion tank are disconnected.

Heating systems are not monitored in winter. If they have worked without breakdowns for up to about three months, then the acceptance of heating networks into operation can be carried out without hydraulic tests. When checking closed heating systems, control work must be carried out before the furrows are closed. If you plan to insulate heating networks, then do so before installing it.

According to SNiP, after testing heating systems, they are washed, and a coupling with a cross-section of 60 to 80 mm2 is mounted at their lowest point. Water drains through it. Flushing of heating networks carried out with cold water several times until it becomes transparent. Approval of heating systems occurs if within 5 minutes the test pressure in the pipeline does not change by more than 20 kiloPascal.

Hydraulic testing of heating and water supply systems (video)

Hydraulic testing of heating networks and water supply systems

After completion of hydraulic tests of heating systems in accordance with SNiP, a hydraulic test report of heating networks and water supply systems is drawn up, indicating the compliance of the pipeline parameters.

According to SNiP, its form contains the following information:

• the title of the position of the head of the enterprise providing maintenance of heating networks;
• his signature and initials, as well as the date of inspection;
• information about the chairman of the commission, as well as its members;
• information on the parameters of heating networks: length, name, etc.;
• conclusions about the control, conclusion of the commission.

Adjustment of the characteristics of heating lines is carried out by SNiP 3.05.03-85. According to the specified SNiP it the rules apply to all highways, which transport water at temperatures up to 220˚C and steam at temperatures up to 440˚C.

To document the completion of hydraulic tests of the water supply system, a report is drawn up for the external water supply system in accordance with SNiP 3.05.01-85. According to SNiP, the act contains the following information:

• name of the system;
• name of the technical supervision organization;
• data on the test pressure and test time;
• pressure drop data;
• presence or absence of signs of damage to the pipeline;
• date of inspection;
• commission withdrawal.

The report is certified by a representative of the supervisory organization.