Foreword
TCVN 4037 : 2012 replaces TCVN 4037 : 1985.
TCVN 4037 : 2012 was converted from TCVN 4037 : 1985 in accordance with the provisions of Clause 1, Article 69 of the Law on Standards and Technical Regulations and Point b), Clause 1, Article 6 of Decree 127/2007/ND-CP detailing the implementation of some articles of the Law on Standards and Technical Regulations.
TCVN 4037:2012 was compiled by the Institute of Architecture, Urban and Rural Planning – Ministry of Construction, proposed by the Ministry of Construction, appraised by the General Department of Standards, Metrology and Quality, and promulgated by the Ministry of Science and Technology.
1. Scope of application
This standard specifies the terminology and definitions applied in the field of water supply.
2. Terminology and definitions
2.1. General concepts
2.1.1. Water supply system
A system that includes: water intake works, pumping stations, water treatment plants, water purification stations, pipeline networks, and storage tanks to provide water of assured quality to water using units.
2.1.2. Water supply system for residential units or building groups
A water supply system for residential building groups and service facilities in residential areas.
2.2. Water demand
2.2.1. Water flow rate
The amount of water flowing through the wet cross-section of a stream per unit time.
2.2.2. Design water flow rate for water supply
The amount of water per unit time, used for designing the water supply network and works.
2.2.3. Water consumption standard
The amount of water supplied to a water using unit per unit time or supplied per unit of product.
2.2.4. Uneven water demand
The fluctuation of water flow rate per unit time.
2.2.5. Uneven water demand coefficient
The ratio between the maximum or minimum water consumption and the average water consumption during a specified time period.
2.2.6. Water loss in the water supply system
The amount of water lost during the process of transportation, distribution, and storage.
2.3. Water intake works
2.3.1. Surface water
Water on the ground surface, in various forms.
2.3.2. Groundwater
Water contained in soil layers in all physical states.
2.3.3. Aquifer
One or several homogeneous sedimentary soil or rock layers that contain gravitational water and have close hydraulic connectivity with each other.
2.3.4. Dug well
A well with a reinforced well wall to collect groundwater through the bottom or through both the bottom and the wall of the well.
2.3.5. Drilled water well
A drilled well equipped with a casing pipe used to collect groundwater.
2.3.6. Radial water intake works
A system of horizontal or sloped radial collection pipes used to collect water in aquifers and concentrate water into a collection well.
2.3.7. Water collection well
A dug well used to collect water from water intake works.
2.3.8. Deep well (artesian well)
A dug well or drilled well used to collect water from confined aquifers.
2.3.9. Filter equipment in dug wells
Equipment used to prevent soil and rock particles from flowing with water from the aquifer into the well.
2.3.10. Protection layer of dug wells
An impervious layer to prevent surface water from flowing into the well.
2.3.11. Wellhead of drilled water wells
The upper part of a drilled water well, which can be sealed when necessary.
2.3.12. Artificial flushing in dug wells
The artificial flushing of small soil particles to create soil stability in dug wells.
2.3.13. Radius of influence of water pumping
The distance from the center of water pumping to a point in the aquifer where the original groundwater level is practically maintained.
2.3.14. Observation well
A well used to observe the groundwater level and quality.
2.3.15. Drilled well yield
The amount of water taken from a drilled water well over a time period, at a specified dynamic water level.
2.3.16. Unit yield of drilled wells
The amount of water taken from a drilled well during the time when the water level drops by 1m.
2.3.17. Infiltration works
Works used to artificially recharge groundwater reserves.
2.3.18. Siphon water pipeline
A water pipeline with a pressure lower than atmospheric pressure.
2.4. Water treatment and purification
2.4.1. Water treatment
The technological processes used to clarify and decolorize water.
2.4.2. Water purification
The technological processes used to treat water to meet the quality required by the water using unit.
2.4.3. Water clarification
The process of removing suspended solids and colloids from water.
2.4.4. Water treatment plant
The entire set of buildings/structures and equipment for water treatment.
2.4.5. Microscreen
A screen-type filter device used to retain small suspended solids and plankton.
2.4.6. Pre-chlorination of water
The introduction of chlorine into water at the initial stage of the water treatment process.
2.4.7. Degasification of water
The process of removing dissolved gases from water.
2.4.8. Chemical preparation area
The entire set of structures and equipment for receiving, mixing, storing, and dosing chemicals introduced into the water treatment process.
2.4.9. Contact tank
A tank used for water to contact and interact with chemicals for a specified period of time.
2.4.10. Water retention time
The average time for water to remain in the structures of the water supply system.
2.4.11. Sedimentation tank
A structure for water clarification.
2.4.12. Sedimentation tank with a suspended sludge layer
A structure for water clarification by allowing water to flow upward through a suspended sludge layer.
2.4.13. Filter for water treatment and purification
A structure used to remove suspended solids from water, and also used for ion exchange or adsorption.
2.4.14. Slow filter
A filter with small-sized filter media, without reactive substances (filtration rate from 0.1 m/h to 0.2 m/h).
2.4.15. Rapid filter
A filter operating at a rate of 2 m/h.
2.4.16. Gravity filter
A filter in which water flows by gravity through the filter media layer.
2.4.17. Pressure filter
A filter in which water flows under pressure through the filter media layer.
2.4.18. Ion exchange filter
A filter with ion exchange resins or macromolecular substances as filter media.
2.4.19. Filter media
The support layer and filter media in a filter, used for water treatment and purification.
2.4.20. Backwash equipment
Equipment used to evenly distribute backwash water and air in the filter, and to collect and discharge backwash water.
2.4.21. Filter layer
A layer of homogeneous filter media or a portion of filter media with a specified height.
2.4.22. Filtration rate
The amount of water flowing through a unit area of filter media per unit time.
2.4.23. Filter cycle
The set of all technological operations between filter backwashes or filter regenerations.
2.4.24. Filter backwash
The removal of contaminants attached to the filter media during the filtration process.
2.4.25. Filter backwash intensity
The amount of water or air introduced for filter backwash per unit area of filter media per unit time.
2.4.26. Dirt holding capacity of filters
The mass of contaminants that the filter media is capable of retaining.
2.4.27. Expansion of filter media
The increase in volume of the filter media during backwash.
2.4.28. Desalination of water
The water treatment process to reduce the concentration of dissolved salts in water to an allowable level.
2.4.29. Water desalination
The desalination process to partially reduce the salt content in water to the specified concentration for drinking water.
2.4.30. Water softening
The water treatment process to reduce the hardness of water.
2.4.31. Water disinfection
The process of reducing the number of pathogenic microorganisms in water to the limit specified by hygiene and epidemic prevention requirements.
2.4.32. Water fluoridation
The process of introducing fluorine compounds into water up to the specified limit, according to hygiene and epidemic prevention requirements.
2.5. Water pipelines, water supply networks, and network structures
2.5.1. Water pipeline
The pipeline and equipment installed on the pipeline used to convey water from the intake works to the water users.
2.5.2. Water supply network
The system of water pipelines and pipeline structures to deliver water to the point of use.
2.5.3. Looped water supply network
A water supply network that delivers water to the point of use from two directions.
2.5.4. Dead-end water supply network
A water supply network that delivers water to the point of use from one direction.
2.5.5. Water service line
The pipeline connecting the external water supply network to the internal water supply pipeline of a building or structure.
2.5.6. Water supply valve box
A structure on the water supply network for installing accessories and managing the network.
2.5.7. Water supply pipeline casing
A pipe used to protect the pipeline when crossing railways, roads, building structures, or when laid through underground utility systems.
2.5.8. Zoned water supply network
An independent part of the water supply network with a specific pressure.
2.5.9. Water supply pumping station
A structure equipped with pumps and power equipment to pump water into water supply pipelines and networks.
2.5.10. Water meter
A device for measuring the water flow rate in a pipeline.
2.6. Water storage and balancing tanks
2.6.1. Water tank
An enclosed structure used to store water.
2.6.2. Water balancing tank
A water tank used to balance the uneven water use in the water supply system.
2.6.3. Pressurized water tank
A water tank mainly used to create pressure in the water supply network and placed at natural or artificial high points.
2.6.4. Buried water tank
A water tank with its bottom placed lower than the natural ground level or the leveled ground level.
2.6.5. Water tower
A pressurized water tank placed on an artificial support structure.
2.6.6. Balancing water volume
The amount of water used to balance the inflow and outflow of water on the day with the highest water use.
2.6.7. Emergency storage water volume
The amount of water stored in a tank to supply water through a pipeline during the time of emergency repair.
