Water supply refers to life support systems, without which office buildings, enterprises, residential buildings cannot function. Effective distribution of water inside the building makes it comfortable, safe, environmentally friendly.
Definition and purpose of the domestic water supply system
An internal water supply system is pipes and devices that ensure the delivery of hot or cold water from an external water conduit to consumers inside the building. Appointment - transportation of liquid of standard parameters: temperature, quality, pressure.
It is not allowed to connect a domestic drinking water conduit to a water supply network supplying process water unsuitable for drinking.
An internal water supply system provides domestic plumbing, technological, and fire-fighting equipment with water. It is supplied from the central water supply system of the settlement, or from a separate well or a natural source. The type of inland water supply is affected by technical capabilities, sanitary and hygiene and fire safety requirements, as well as the economic feasibility of the project.
Requirements for domestic water supply
Basic requirements for water supply: efficiency, reliability of supply and water quality for the consumer. In accordance with sanitary norms and rules (SNiP), internal water supply systems:
- equipped with metering devices for the volume of fluid consumed;
- equipped with pressure control and regulation devices in the system;
- materials for water pipes should be environmentally friendly and chemically inert;
- drinking water to meet sanitary standards passes through several stages of purification, clarification;
- the liquid from the technical water main is not used for drinking, but it goes through the purification stages necessary for the technological process;
- to optimize water supply systems, they are combined as much as possible, which reduces operating costs.
Reliability of work is ensured by the simultaneous laying of two water lines with switches between them, so that one of the pipes can be repaired or replaced without interrupting the water supply.
To ensure uninterrupted supply with one thread of water supply, provide storage tanks.
In accordance with SNiP, the internal water supply system transports water with preservation of: temperature, transparency or turbidity, ion-salt composition, acid-base indicators, hardness, amount of dissolved oxygen and carbon dioxide.
The temperature of the hot water in the domestic water supply must not be lower than 50-60 degrees in order to prevent the development of microorganisms. But should not exceed 75 degrees for consumer safety. For example, in children's institutions, the temperature of the hot water supply is reduced to 37 degrees.
The minimum free pressure of the internal water supply in a one-story building should be 10 m, in multi-story buildings, an increase of 4 m per floor is provided.
Internal water supply supports microbiological characteristics. Drinking water should be free of microorganisms and their metabolic products, regulated coli index (the number of E. coli in 1 kg of water) no more than 3.
Types and device
Water supply systems are classified according to common features. Depending on the destination, the types of internal water supply are distinguished:
- production - supply water to workshops at industrial enterprises;
- household-drinking - supply drinking water to residential buildings or workers in the workplace;
- fireproof - provide water during fires.
It is possible to combine all water supply systems in one production-drinking-fire conduit. It is expensive if you have to spend a lot of clean water on production needs. More often, a fire-fighting water supply system is created using drinking water.
According to the method of transporting liquid, water conduits:
- self-flowing;
- with spare tanks;
- with booster pumps;
- combined.
The design features and composition of the internal water supply depend on the required quality and volume of fluid in a residential building or industrial building. The basic device includes:
- input, one or more;
- water meter unit: counter;
- technological equipment to increase the pressure: pumps for feeding to the upper floors;
- fittings: locking, safety, adjusting, mixing;
- connecting elements for pipe installation: elbows, adapters, fittings, bends;
- distributing horizontal network of pipes;
- vertical risers with connection to the sanitary equipment of consumers;
- spare tanks.
Sometimes devices are provided for additional cleaning, deferrization, softening, degassing, or disinfection.
The hot water supply system is organized similarly to cold, a feature is the need for thermal insulation of pipes passing through the building to prevent premature cooling. By way of organizing, domestic hot water systems are circular or dead ends.
Internal Network Design
Providing the necessary pressure for drinking or household water from the consumer using pipes of the minimum length is the main task of designing internal water supply.
The internal water supply fits into the interior of buildings or premises without violating the design and main structure. Consider the following:
- The calculations are based on the maximum amount of water used per unit time (1 second).
- The flow rate in the pipes of the internal water conduit, including fire, is not more than 3 m / s.
- In the presence of two inputs, each of them is calculated on 100% loading to ensure uninterrupted supply one by one at shutdown of the second. If there are more inputs, the liquid flow rate is 50%.
- The internal water supply is laid out from pipes, the diameter of which allows efficient use of the pressure of the external water supply at the highest water consumption in the building.
- The diameter of the annular bridge pipes corresponds to the largest diameter of the riser pipes.
- The device provides vibration isolation bases for pumping units.
- In apartment buildings or public buildings, the most hidden installation of internal water supply networks is carried out in rooms with a temperature of at least 2 degrees. Used technical basements, attics, underground channels of utilities.
In difficult cases, the design of the internal water supply system, hydraulic calculations, determination of equipment parameters is carried out by specialists taking into account the requirements of SNiP 2.04.01-85 *.
Basic mounting schemes
Installation of domestic water supply systems is carried out according to the schemes:
- Bottom wiring without water pumping devices. Mounted in the basement. The pressure in the internal network is ensured by the pressure of the external water supply system.
- Bottom wiring with booster pump. Installed in the basement. The pressure is created by the pump.
- Top wiring with storage tank. Mounted in the attic or technical floor. The pressure is created by the water tank.
- Ring circuit. It is installed if there are two or more inputs in the system for uninterrupted water supply: in residential buildings, where there are more than 400 apartments; public buildings visited by a large number of people (theaters, clubs, cinemas, baths); at installation at the same time 12 and more fire hydrants.
Installation of the water supply system is done by employees of specialized organizations in various ways: in bulk - assembly of parts and devices in place, used for individual projects; blocks - for typical building projects; sanitary cabins, where the main pipes are installed at the plant - used in large-panel housing construction.
