What are external water supply networks. External water supply and sewerage systems. Connection method depends on the type of material used

8.1. The number of water lines should be taken taking into account the category of the water supply system and the sequence of construction.

8.2. When laying water conduits in two or more lines, the need for a device for switching between water conduits is determined depending on the number of independent water intake structures or water conduit lines supplying water to the consumer, while in the event that one conduit or its section is disconnected, the total water supply to the facility for household and drinking needs can be reduced no more than 30% of the estimated consumption, for production needs - according to the emergency schedule.

8.3. When laying a conduit in one line and supplying water from one source, the volume of water must be provided for the time of liquidation of an accident on the conduit in accordance with clause 9.6. When water is supplied from several sources, the emergency volume of water can be reduced, provided that the requirements of clause 8.2 are met.

8.4. The estimated time to eliminate an accident on pipelines of water supply systems of category I should be taken according to Table. 34. For water supply systems of categories II and III, the time indicated in the table should be increased by 1.25 and 1.5 times, respectively.

Table 34

Notes: 1. Depending on the material and diameter of the pipes, the characteristics of the route of water conduits, the conditions for laying pipes, the availability of roads, vehicles and emergency response facilities, the specified time may be changed, but should be taken at least 6 hours.

2. It is allowed to increase the time of liquidation of the accident, provided that the duration of interruptions in the supply of water and a decrease in its supply will not exceed the limits specified in clause 4.4.

3. If it is necessary to disinfect pipelines after the liquidation of the accident, the time indicated in the table should be increased by 12 hours.

8.5. Water networks should be ring. Dead-end water lines are allowed to be used:

for supplying water for production needs - if a break in water supply is admissible for the period of liquidation of the accident;

for supplying water for household and drinking needs - with a pipe diameter of not more than 100 mm;

for supplying water for fire-fighting or household fire-fighting needs, regardless of the water consumption for fire extinguishing - with a line length of not more than 200 m.

Ringing of external water supply networks with internal water supply networks of buildings and structures is not allowed.

Note. In settlements with a population of up to 5 thousand people. and water consumption for external fire extinguishing up to 10 l / s or with the number of internal fire hydrants in the rank up to 12, dead-end lines with a length of more than 200 m are allowed, provided that fire-fighting tanks or reservoirs, a water tower or a counter-reservoir at the end of the dead end are installed.

8.6. When turning off one section (between settlement nodes), the total water supply for household and drinking needs along the remaining lines should be at least 70% of the calculated flow rate, and the water supply to the most unfavorably located water intake points should be at least 25% of the calculated water consumption, while free head should be at least 10 m.

8.7. The device of accompanying lines for connecting associated consumers is allowed with a diameter of main lines and water conduits of 800 mm or more and a transit flow of at least 80% of the total flow; for smaller diameters - upon justification.

With a width of passages of more than 20 m, it is allowed to lay duplicate lines, excluding the intersection of passages with inputs.

In these cases, fire hydrants should be installed on accompanying or backup lines.

If the width of the streets within the red lines is 60 m or more, the option of laying water supply networks on both sides of the streets should also be considered.

8.8. The connection of networks of domestic drinking water supply systems with networks of water supply systems supplying water of non-potable quality is not allowed.

Note. In exceptional cases, in agreement with the bodies of the sanitary and epidemiological service, it is allowed to use a drinking water supply system as a reserve for a water supply system that supplies water of non-potable quality. The design of the jumper in these cases should provide an air gap between the networks and exclude the possibility of reverse water flow.

8.9. On water conduits and lines of the water supply network, if necessary, it is necessary to provide for the installation of:

rotary gates (latches) for allocation of repair sites;

valves for air inlet and outlet when emptying and filling pipelines;

valves for air inlet and pinching;

plungers for air release during pipeline operation;

releases for water discharge when emptying pipelines;

compensators;

mounting inserts;

check valves or other types of automatic valves for shutting down repair areas;

pressure regulators;

devices for preventing pressure increase in case of hydraulic shocks or in case of malfunction of pressure regulators.

On pipelines with a diameter of 800 mm or more, manholes are allowed (for inspection and cleaning of pipes, repair of shut-off and control valves, etc.).

On gravity-pressure water conduits, provision should be made for the installation of unloading chambers or the installation of equipment that protects water conduits under all possible operating modes from increasing pressure above the limit permissible for the accepted type of pipes.

Note. The use of valves instead of butterfly valves is allowed if it is necessary to systematically clean the inner surface of pipelines with special units.

8.10. The length of repair sections of conduits should be taken: when laying conduits in two or more lines and in the absence of switching - no more than 5 km; in the presence of switching - equal to the length of the sections between switching, but not more than 5 km; when laying water conduits in one line - no more than 3 km.

Note. The division of the water supply network into repair sections should ensure that when one of the sections is turned off, no more than five fire hydrants are turned off and water is supplied to consumers who do not allow a break in water supply.

With justification, the length of the repair sections of water conduits can be increased.

8.11. Automatic valves for air inlet and outlet should be provided at elevated breakpoints of the profile and at the upper boundary points of the repair sections of water conduits and networks to prevent the formation of a vacuum in the pipeline, the value of which exceeds the allowable value for the accepted type of pipes, as well as to remove air from the pipeline when it filling.

When the vacuum value does not exceed the allowable one, manually operated valves can be used.

Instead of automatic valves for air inlet and outlet, it is allowed to provide automatic valves for air inlet and pinching with manually operated valves (gates, dampers) or air vents, depending on the flow rate of the air being removed.

8.12. Plungers should be provided at elevated turning points of the profile on the air collectors. The diameter of the air collector should be taken equal to the diameter of the pipeline, the height - 200-500 mm, depending on the diameter of the pipeline.

When justified, it is allowed to use air collectors of other sizes.

The diameter of the shut-off valves that disconnect the air vent from the air collector should be taken equal to the diameter of the air vent connecting pipe.

The required capacity of the vents should be determined by calculation or taken equal to 4% of the maximum design flow rate of water supplied through the pipeline, counting by air volume at normal atmospheric pressure.

If there are several elevated turning points of the profile on the conduit, then at the second and subsequent points (counting in the direction of water movement), the required capacity of the plungers can be taken equal to 1% of the maximum design water flow, provided that this turning point is located below the first or above it by no more than 20 mi at a distance from the previous one no more than 1 km.

Note. When the slope of the descending section of the pipeline (after the turning point of the profile) is 0.005 or less, plungers are not provided; with a slope within 0.005-0.01 at the turning point of the profile, instead of a plunger, it is allowed to provide a tap (valve) on the air collector.

8.13. Water conduits and water supply networks should be designed with a slope of at least 0.001 towards the outlet; with flat terrain, the slope can be reduced to 0.0005.

8.14. Releases should be provided at the low points of each repair site, as well as at the points of release of water from flushing pipelines.

The diameters of the outlets and devices for air inlet should ensure the emptying of sections of water conduits or networks in no more than 2 hours.

The design of outlets for flushing pipelines should ensure the possibility of creating a water velocity in the pipeline of at least 1.1 maximum design.

Butterfly valves should be used as stop valves.

Note. During hydropneumatic flushing, the minimum speed of the mixture (in places of greatest pressure) should be at least 1.2 times the maximum speed of the water, the water flow should be 10–25% of the volume flow of the mixture.

8.15. Water drainage from outlets should be provided to the nearest drain, ditch, ravine, etc. If it is impossible to drain all or part of the discharged water by gravity, it is allowed to discharge water into the well with subsequent pumping.

8.16. Fire hydrants should be provided along highways at a distance of no more than 2.5 m from the edge of the carriageway, but not closer than 5 m from the walls of buildings; it is allowed to have hydrants on the roadway. At the same time, the installation of hydrants on a branch from the water supply line is not allowed.

The arrangement of fire hydrants on the water supply network should ensure fire extinguishing of any mania, structure or part of it served by this network from at least two hydrants at a water flow rate for external fire extinguishing of 15 l / s or more and one - at a hearth flow rate of less than 15 l / s, taking into account laying hose lines with a length not exceeding that specified in clause 9.30 on paved roads.

The distance between the hydrants is determined by a calculation that takes into account the total water consumption for fire extinguishing and the throughput of the installed type of hydrants according to GOST 8220-85 * E.

Head loss h, m, per 1 m length of hose lines should be determined by the formula

where q n — fire jet productivity, l/s.

Note. On the water supply network of settlements with a population of up to 500 people. instead of hydrants, it is allowed to install risers with a diameter of 80 mm with fire hydrants.

8.17. Compensators should include:

on pipelines, the butt joints of which do not compensate for axial movements caused by changes in the temperature of water, air, soil;

on steel pipelines laid in tunnels, channels or on overpasses (supports);

on pipelines in conditions of possible soil subsidence.

The distances between compensators and fixed supports should be determined by a calculation that takes into account their design. When laying underground water conduits, mains and a network line made of steel pipes with welded joints, expansion joints should be provided at the installation sites of cast-iron flange fittings. In cases where the cast-iron flanged reinforcement is protected from the effects of axial tensile forces by rigidly embedding steel pipes in the walls of the well, by installing special stops or by compressing the pipes with compacted soil, compensators may not be provided.

When compressing pipes with soil in front of flanged cast-iron fittings, movable butt joints (elongated socket, coupling, etc.) should be used. Compensators and movable butt joints for underground laying of pipelines should be located in wells.

8.18. Mounting inserts should be accepted for dismantling, routine inspection and repair of flanged shut-off, safety and control valves.

8.19. Shutoff valves on water conduits and lines of the water supply network must be manually or mechanically driven (from mobile vehicles).

The use of shut-off valves with an electric or hydraulic drive on water conduits is allowed with remote or automatic control.

8.20. The radius of action of the water intake column should be taken no more than 100 m. Around the water intake column, a blind area 1 m wide with a slope of 0.1 from the column should be provided.

8.21. The choice of material and strength class of pipes for water conduits and water networks should be taken on the basis of a static calculation, the aggressiveness of the soil and transported water, as well as the operating conditions of pipelines and water quality requirements.

For pressure conduits and networks, as a rule, non-metallic pipes (reinforced concrete pressure pipes, asbestos-cement pressure pipes, plastic pipes, etc.) should be used. Refusal to use non-metallic pipes must be justified.

The use of cast-iron pressure rough is allowed for networks within settlements, territories of industrial, agricultural enterprises.

The use of steel pipes is allowed:

in areas with a design internal pressure of more than 1.5 MPa (15 kgf / cm2);

for crossing the floor by railways and roads, through water barriers and ravines;

at the intersection of the utility and drinking water supply with sewerage networks;

when laying pipelines along road and city bridges, along overpass supports and in tunnels.

Steel pipes should be taken in economical grades with a wall thickness of which should be determined by calculation (but not less than 2 mm) taking into account the operating conditions of pipelines.

For reinforced concrete and asbestos-cement pipelines, the use of metal fittings is allowed.

The material of pipes in domestic and drinking water supply systems must meet the requirements of clause 1.3.

8.22. The value of the calculated internal pressure should be taken equal to the highest possible pressure in the pipeline in various sections along the length (in the most unfavorable operating mode) without taking into account the increase in pressure during hydraulic shock or with the increase in pressure during hydraulic shock, taking into account the action of shockproof fittings, if this pressure in combination with other loads (clause 8.26) will have a greater impact on the pipeline.

Static analysis should be carried out for the effect of the design internal pressure, soil pressure, live loads, the dead weight of the pipes and the mass of the transported liquid, atmospheric pressure during the formation of a vacuum and the external hydrostatic pressure of groundwater in those combinations that turn out to be the most dangerous for pipes of this material.

Pipelines or their sections should be divided according to the degree of responsibility into the following classes:

1 - pipelines for objects of the I category of water supply, as well as sections of pipelines in the zones of transition through water barriers and ravines, railways and roads of I and II categories and in places difficult to access to eliminate possible damage, for objects of II and III categories of supply security water;

2 - pipelines for objects of the II category of water supply availability (with the exception of sections of the 1st class), as well as sections of pipelines laid under improved road surfaces for objects of the III category of water supply availability;

3 - all other sections of pipelines for objects of the III category of water supply availability.

In the calculation of pipes, one should take into account the coefficient of operating conditions of the vehicle, determined by the formula

where m 1 , - coefficient taking into account the short duration of the test to which the pipes are subjected after their manufacture;

T 2 — coefficient taking into account the decrease in the strength characteristics of pipes during operation as a result of aging of the pipe material, corrosion or abrasion wear;

g n - reliability factor, taking into account the class of the pipeline section according to the degree of responsibility.

Coefficient value T 1 should be installed in accordance with GOST or technical specifications for the manufacture of this type of pipe.

For pipelines, the butt joints of which are equal in strength to the pipes themselves, the value of the coefficient m 1 should be taken equal to:

0.9 - for cast iron, steel, asbestos-cement, concrete, reinforced concrete and ceramic pipes;

1 - for polyethylene pipes.

Coefficient value T 2 should be taken equal to:

1 - for ceramic pipes, as well as cast iron, steel, asbestos-cement, concrete and reinforced concrete pipes, in the absence of a risk of corrosion or abrasive wear in accordance with GOST or technical specifications for the manufacture of this type of pipe - for plastic pipes.

The value of the coefficient g n should be taken: for sections of pipelines of the 1st class - 1; 2nd class - 0.95; 3rd class - 0.9.

8.23. The magnitude of the test pressure at various test sections to which pipelines must be subjected before commissioning should be indicated in the construction organization projects, based on the strength indicators of the material and class of pipes adopted for each section of the pipeline, the calculated internal water pressure and the magnitude of external loads acting on pipeline during the test period.

The calculated value of the test pressure should not exceed the following values ​​for pipe pipelines:

cast iron - factory test pressure with a coefficient of 0.5;

reinforced concrete and asbestos-cement - hydrostatic pressure provided for by GOST or technical conditions for the corresponding classes of pipes in the absence of external load;

steel and plastic - internal design pressure with a coefficient of 1.25.

8.24. Cast iron, asbestos-cement, concrete, reinforced concrete and ceramic pipelines must be designed for the combined effect of the calculated internal pressure and the calculated reduced external load.

Steel and plastic pipelines must be designed for the effect of internal pressure in accordance with clause 8.23 ​​and for the combined effect of the external reduced load, atmospheric pressure, as well as for the stability of the round cross-section of the pipes.

The shortening of the vertical diameter of steel pipes without internal protective coatings should not exceed 3%, and for steel pipes with internal protective coatings and plastic pipes, it should be taken according to the standards or specifications for these pipes.

When determining the vacuum value, the action of anti-vacuum devices provided on the pipeline should be taken into account.

8.25. As temporary loads should be taken:

for pipelines laid under railways - the load corresponding to the class of the given railway line;

for pipelines laid under roads - from a column of H-30 cars or wheeled transport NK-80 (for greater force on the pipeline);

for pipelines laid in places where traffic of motor vehicles is possible - from a column of H-18 vehicles or caterpillar vehicles NG-60 (for greater force on the pipeline);

for pipelines laid in places where the movement of road transport is impossible - a uniformly distributed load of 5 kPa (500 kgf / m2).

8.26. When calculating pipelines for pressure increase during hydraulic shock (determined taking into account shockproof fittings or vacuum formation), the external load should be taken no more than the load from the column of H-18 vehicles.

8.27. The increase in pressure during hydraulic shock should be determined by calculation and, on its basis, protective measures should be taken.

Measures to protect water supply systems from water hammer should be provided for the following cases:

sudden shutdown of all or a group of pumps working together due to a power failure;

shutdown of one of the pumps working together before closing the butterfly valve (valve) on its pressure line;

starting the pump with an open butterfly valve (valve) on the pressure line equipped with a check valve;

mechanized closing of the rotary gate (valve) when the water conduit is turned off as a whole or its individual sections;

opening or closing quick-acting water fittings.

8.28. As measures to protect against water hammer caused by a sudden shutdown or start-up of pumps, the following should be taken:

installation of valves on the water conduit for air inlet and pinching;

installation of non-return valves with adjustable opening and closing on pressure lines of pumps;

installation of check valves on the conduit, dividing the conduit into separate sections with a small static pressure on each of them;

discharge of water through the pumps in the opposite direction with their free rotation or full braking;

installation at the beginning of the conduit (on the pressure line of the pump) of air-water chambers (caps) that soften the process of hydraulic shock.

Note. To protect against water hammer, it is allowed to use: installation of safety valves and damper valves, discharge of water from the pressure line to the suction line, water inlet in places of possible formation of flow continuity breaks in the conduit, installation of blind diaphragms that collapse when pressure rises above the permissible limit, device water columns, the use of pumping units with greater inertia of the rotating masses.

8.29. The protection of pipelines from the increase in pressure caused by the closing of the butterfly valve (valve) must be ensured by increasing the time of this closing. If the closing time of the valve with the accepted type of drive is insufficient, additional protection measures should be taken (installation of safety valves, air caps, water columns, etc.).

8.30. Water lines, as a rule, should take underground laying. During the heat engineering and feasibility study, ground and above-ground laying, laying in tunnels, as well as laying of water lines in tunnels together with other underground utilities, is allowed, with the exception of pipelines transporting flammable and combustible liquids and combustible gases. When laying fire lines and combined with fire water pipelines in tunnels, ground or above ground fire hydrants should be installed in wells.

When laying underground, shut-off, control and safety pipeline fittings should be installed in wells (chambers).

Wellless installation of shut-off valves is allowed upon justification.

8.31. The type of foundation for pipes must be taken depending on the bearing capacity of the soil and the magnitude of the loads.

In all soils, with the exception of rocky, peaty and silt, pipes should be laid on natural soil of an undisturbed structure, while ensuring leveling, and, if necessary, profiling the base.

For rocky soils, leveling of the base with a layer of sandy soil 10 cm thick above the ledges should be provided. It is allowed to use local soil (sandy loam and loam) for these purposes, provided it is compacted to a bulk density of the soil skeleton of 1.5 t/m3.

When laying pipelines in wet cohesive soils (loam, clay), the need for sand preparation is established by the project for the production of works, depending on the measures for dewatering, as well as on the type and design of pipes.

In silts, peaty and other weak water-saturated soils, pipes must be laid on an artificial base.

8.32. In cases where steel pipes are used, protection of their outer and inner surfaces from corrosion should be provided. In this case, the materials specified in clause 1.3 should be used.

8.33. The choice of methods for protecting the outer surface of steel pipes from corrosion should be justified by data on the corrosive properties of the soil, as well as data on the possibility of corrosion caused by stray currents.

8.34*. In order to prevent corrosion and overgrowth of steel conduits and water supply networks with a diameter of 300 mm or more, protection of the inner surface of such pipelines with coatings: sand-cement, paintwork, zinc, etc.

Note. Instead of coatings, it is allowed to use stabilization treatment of water or its treatment with inhibitors in accordance with the recommended Appendix 5 in cases where technical and economic calculations, taking into account the quality, consumption and purpose of water, confirm the feasibility of such protection of pipelines from corrosion.

Paragraph 8.35 is deleted.

8.36. Concrete corrosion protection of cement-sand coatings of pipes with a steel core from the effects of sulfate ions should be provided with insulating coatings in accordance with SNiP 2.03.11-85.

8.37. Protection of pipes with a steel core against corrosion caused by stray currents should be provided in accordance with the requirements of the Instruction for the protection of reinforced concrete structures from corrosion caused by stray currents.

8.38. For pipes with a steel core, having an outer layer of concrete with a density below normal with an allowable crack opening width at design loads of 0.2 mm, it is necessary to provide for electrochemical protection of pipelines with cathodic polarization at a concentration of chloride ions in the soil of more than 150 mg/l; at normal concrete density and allowable crack width of 0.1 mm - more than 300 mg/l.

8.39. When designing pipelines from steel and reinforced concrete pipes of all types, it is necessary to provide for measures to ensure continuous electrical conductivity of these pipes in order to be able to provide electrochemical protection against corrosion.

8.40. The cathodic polarization of pipes with a steel core should be designed so that the protective polarization potentials created on the metal surface, measured at specially arranged control and measuring points, are not lower than 0.85 V and not higher than 1.2 V using a copper sulfate reference electrode.

8.41. During electrochemical protection of pipes with a steel core using protectors, the value of the polarization potential should be determined with respect to a copper-sulfate reference electrode installed on the surface of the pipe, and when protected using cathode stations, with respect to a copper-sulfate reference electrode located in the ground.

8.42. The depth of laying pipes, counting to the bottom, should be 0.5 m more than the calculated depth of penetration into the soil of zero temperature.

When laying pipelines in the zone of negative temperatures, the material of pipes and elements of butt joints must meet the requirements of frost resistance.

Note. A smaller depth of laying of pipes is allowed to be taken, subject to the adoption of measures that exclude: freezing of fittings installed on the pipeline; unacceptable reduction in the throughput of the pipeline as a result of the formation of ice on the inner surface of the pipes; damage to pipes and their butt joints as a result of water freezing, soil deformation and thermal stresses in the pipe wall material; the formation of ice plugs in the pipeline during interruptions in the water supply associated with damage to the pipelines.

8.43. The estimated depth of penetration into the soil of zero temperature should be established on the basis of observations of the actual depth of freezing in the calculated cold and little snow winter and the experience of operating pipelines in this area, taking into account possible changes in the previously observed freezing depth as a result of planned changes in the state of the territory (removal of snow cover, arrangement improved road surfaces, etc.).

In the absence of observational data, the depth of penetration into the soil of zero temperature and its possible change due to the proposed changes in the improvement of the territory should be determined by thermal engineering calculations.

8.44. To prevent heating of water in the summer, the depth of laying of pipelines of domestic and drinking water pipelines should, as a rule, be taken at least 0.5 m, counting to the top of the pipes. It is allowed to accept a smaller depth of laying water conduits or sections of the water supply network, subject to justification by thermal engineering calculations.

8.45. When determining the depth of laying of water conduits and water supply networks during underground laying, external loads from transport and the conditions of intersection with other underground structures and communications should be taken into account.

8.46. The choice of pipe diameters for water conduits and water supply networks should be made on the basis of technical and economic calculations, taking into account the conditions for their operation during emergency shutdown of individual sections.

The diameter of the pipes of the water supply system, combined with the fire-fighting one, in settlements and industrial enterprises must be at least 100 mm, in rural settlements - at least 75 mm.

8.47. The value of the hydraulic slope to determine the pressure loss in pipelines during the transportation of water that does not have pronounced corrosive properties and does not contain suspended impurities, the deposition of which can lead to intensive overgrowth of pipes, should be taken in accordance with the mandatory appendix. 10.

8.48. For existing networks and water conduits, if necessary, measures should be taken to restore and maintain throughput by cleaning the inner surface of steel pipes and applying an anti-corrosion protective coating; in exceptional cases, in agreement with the state construction agencies of the Union republics, it is allowed to take the actual pressure losses during a feasibility study.

8.49. When designing new and reconstructing existing water supply systems, devices and devices should be provided for the systematic determination of the hydraulic resistance of pipelines in the control sections of water conduits and networks.

8.50. The location of the water supply lines on the master plans, as well as the minimum distances in the plan and at intersections from the outer surface of the pipes to structures and engineering networks, should be taken in accordance with SNiP II-89-80 *.

8.51. When laying several lines of water conduits in parallel (newly or in addition to existing ones), the distance in the plan between the outer surfaces of the pipes should be set taking into account the production and organization of work and the need to protect adjacent water conduits from damage in the event of an accident on one of them:

with an acceptable reduction in the supply of water to consumers, provided for in clause 8.2, - according to table. 35 depending on pipe material, internal pressure and geological conditions;

if there is a spare tank at the end of the conduits that allows interruptions in the supply of water, the volume of which meets the requirements of clause 9.6 - according to table. 35 as for pipes laid in rocky soils.

In some sections of the route of water conduits, including in the areas of laying water conduits in the built-up area and on the territory of industrial enterprises, given in Table. 35 distances may be reduced if the pipes are laid on an artificial foundation, in a tunnel, a case, or when using other laying methods that exclude the possibility of damage to neighboring water conduits in the event of an accident on one of them. At the same time, the distances between the conduits should ensure the possibility of performing work both during laying and during subsequent repairs.

8.52. When laying water lines in tunnels, the distance from the pipe wall to the inner surface of the enclosing structures and the walls of other pipelines should be at least 0.2 m; when installing fittings on the pipeline, the distances to the enclosing structures should be taken in accordance with clause 8.63.

8.53. Pipeline crossings under railways of categories I, II and III, the general network, as well as under roads of categories I and II should be accepted in cases, while, as a rule, a closed method of work should be provided. When justified, it is allowed to provide for the laying of pipelines in tunnels.

Under the rest of the railways and roads, it is allowed to arrange pipeline crossings without cases, while, as a rule, steel pipes and an open method of work should be used.

Notes: 1. Laying pipelines on railway bridges and overpasses, pedestrian bridges over tracks, in railway, road and pedestrian tunnels, as well as in culverts is not allowed.

2. Cases and tunnels under railways with an open method of work should be designed in accordance with SNiP 2.05.03-84 *.

Table 35

		Type of soil (according to the nomenclature of SNiP 2.02.01-83*)
Pipe material	Diameter, mm	rocky		coarse-grained rocks, gravelly sand, coarse sand, clays		medium-sized sand, fine sand, silty sand, sandy loam, loam, soils mixed with plant residues, peaty soils
		Pressure, MPa (kgf / cm 2)
		£1 (10)	> 1 (10)	£1 (10)	> 1 (10)	£1 (10)	> 1 (10)
		Distances in the plan between the outer surfaces of the pipes, m
Steel
Steel	St. 400 to 1000
Steel
Cast iron
Cast iron
Reinforced concrete
Reinforced concrete
Asbestos-cement
plastic
plastic

Notes: 1. In case of parallel laying of water conduits at different levels, the distances indicated in the table should be increased based on the difference in pipe elevations.

2. For conduits that differ in diameter and material of pipes, distances should be taken according to the type of pipes for which they turn out to be large.

8.54. The vertical distance from the bottom of the rail of a railway track or from the pavement of a highway to the top of a pipe, case or tunnel should be taken in accordance with SNiP II-89-80 *.

Deepening of pipelines at crossing points in the presence of heaving soils should be determined by thermal engineering calculation in order to exclude frost heaving of the soil.

8.55. The distance in plan from the edge of the case, and in the case of a device at the end of the well case - from the outer surface of the well wall should be taken:

when crossing railways - 8 m from the axis of the extreme track, 5 m from the bottom of the embankment, 3 m from the edge of the excavation and from the extreme drainage structures (cuvettes, upland ditches, flumes and drains);

when crossing motor roads - 3 m from the edge of the subgrade or the bottom of the embankment, the edge of the excavation, the outer edge of the upland ditch or other drainage structure.

The distance in plan from the outer surface of the case or tunnel should be taken at least:

3 m - to the supports of the contact network;

10 m - to the switches, crosses and places where the suction cable is connected to the rails of electrified roads;

30 m - to bridges, culverts, tunnels and other artificial structures.

Note. The distance from the edge of the case (tunnel) should be specified depending on the availability of long-distance communication cables, signaling, etc., roads laid in the distance.

8.56. The inner diameter of the case should be taken during the production of works:

open method - 200 mm more than the outer diameter of the pipeline;

closed way - depending on the length of the transition and the diameter of the pipeline in accordance with SNiP III-4-80 *.

Note. It is allowed to lay several pipelines in one case or tunnel, as well as joint laying of pipelines and communications (electric cables, communications, etc.).

8.57. Pipeline crossings over railways should be provided in cases on special overpasses, taking into account the requirements of paragraphs. 8.55 and 8.59.

8.58. When crossing an electrified railway, measures must be taken to protect pipes from corrosion caused by stray currents.

8.59. When designing crossings over railways of categories I, II and III of the general network, as well as highways of categories I and II, measures should be taken to prevent undermining or flooding of roads in case of damage to pipelines.

At the same time, on the pipeline on both sides of the crossing under the railways, as a rule, wells should be provided with the installation of shutoff valves in them.

8.60. The project for crossing railways and motor roads must be coordinated with the bodies of the Ministry of Communications or the Ministry of Construction and Maintenance of Motor Roads of the Union Republics.

8.61. When crossing pipelines through watercourses, the number of siphon lines must be at least two; when one line is switched off, the others must be supplied with 100% of the calculated water flow. The siphon lines must be laid from steel pipes with reinforced anti-corrosion insulation, protected from mechanical damage.

The design of a siphon through navigable watercourses must be coordinated with the authorities of the river fleet of the Union republics.

The depth of laying the underwater part of the pipeline to the top of the pipe should be at least 0.5 m below the bottom of the watercourse, and within the fairway on navigable watercourses - at least 1 m. In this case, the possibility of erosion and reformation of the watercourse channel should be taken into account.

The clear distance between the siphon lines must be at least 1.5 m.

The slope of the ascending part of the siphon should be taken no more than 20 ° to the horizon.

On both sides of the siphon, it is necessary to provide for the installation of wells and switches with the installation of shut-off valves.

The layout mark at the siphon wells should be taken 0.5 m above the maximum water level in the watercourse with a security of 5%.

8.62. At turns in the horizontal or vertical plane of pipelines from socket pipes or connected by couplings, when the resulting forces cannot be absorbed by the pipe joints, stops should be provided.

On welded pipelines, stops should be provided when the turns are located in wells or the angle of rotation in the vertical plane of the bulge is upwards of 30 ° or more.

Note. On pipelines made of socket pipes or connected by couplings with a working pressure of up to 1 MPa (10 kgf / cm2), at angles of rotation up to 10 °, it is allowed not to provide stops.

8.63. When determining the dimensions of wells, the minimum distances to the internal surfaces of the well should be taken:

from the walls of pipes with a pipe diameter of up to 400 mm - 0.3 m, from 500 to 600 mm - 0.5 m, more than 600 mm - 0.7 m;

from the plane of the flange with a pipe diameter of up to 400 mm - 0.3 m, more than 400 mm - 0.5 m;

from the edge of the socket facing the wall, with a pipe diameter of up to 300 mm - 0.4 m, more than 300 mm - 0.5 m;

from the bottom of the pipe to the bottom with a pipe diameter of up to 400 mm - 0.25 m, from 500 to 600 mm - 0.3 m, more than 600 mm - 0.35 m;

from the top of the stem of the valve with a rising stem - 0.3 m, from the handwheel of the valve with a non-rising stem - 0.5 m.

The height of the working part of the wells must be at least 1.5 m.

8.64. In cases of installation of air inlet valves located in wells on water conduits, it is necessary to provide for a ventilation pipe, which, in the case of drinking water supply through water conduits, must be equipped with a filter.

8.65. For descending into the well on the neck and walls of the well, it is necessary to provide for the installation of corrugated steel or cast-iron brackets, the use of portable metal ladders is allowed.

For maintenance of fittings in wells, if necessary, sites should be provided in accordance with clause 12.7.

Appendix 3
Appendix 4
Annex 5

An integral part of any housing construction is design, which provides not only for the layout of the premises, but also for the installation of communication systems. Regardless of whether a private house or municipal real estate will be built, the installation of water supply and sewerage is considered a prerequisite for the operation of the building. These systems are placed inside and outside the structure, taking into account the established norms and rules.

General device and purpose

Water supply and sewerage are a single system that combines a number of measures aimed at providing the building with water and draining wastewater. Thanks to a complex of engineering devices and structures, water is supplied to consumers from natural sources, undergoing preliminary purification.

In order for the water supply to be uninterrupted, the communications necessarily provide for the storage of reserves, this allows you to provide water to various economic facilities and settlements. Therefore, the main tasks of the water supply include: obtaining water from the source, controlling its quality according to the requirements of users and direct transportation to sampling points. Such supply, as a rule, is carried out from local or centralized sources and has its own water supply scheme.

The design of communications depends on the choice of water source. For large and industrial facilities, centralized sources are usually chosen, and special tanks are used for local intake. As for the water supply with hot water, it is most often installed in the form of a closed water intake, where heating and subsequent transportation takes place.

For residential premises, the norm of hot water in the water supply system provides for a lower limit of + 60С and an upper limit of + 75С.

Depending on the operational purpose of the building, the following types of water supply are distinguished:

• industrial;
• fireman;
• negotiable;
• economic and drinking;
• for the supply of hot water.

Fire water supply can be combined with other systems, including industrial and drinking water. As for drinking water supply, it cannot be used with facilities that simultaneously transport water that does not meet sanitary standards. In order for communication systems to cope with their tasks, they are provided with the following facilities:

• water intake stations responsible for the intake of water from a natural source object;
• pumping stations that create the required pressure during transportation and supply water to a given height;
• treatment and purification facilities that improve water quality;
• plumbing systems and conduits;
• reserve and control tanks.

outdoor network

Modern plumbing systems are a complex network, the main component of which is considered to be an external pipeline. He is responsible for the supply of water from wells, reservoirs or storage facilities to the consumer, the central water supply system can be laid both on the surface and underground. The first installation option is the cheapest, characterized by quick installation. In this case, the water supply is mounted on elevated supports and additionally covered with insulation. If, when designing a water supply system, main intersections are provided, then pipe laying is carried out in underground tunnels or trenches.

The external network, as a rule, consists of facilities responsible for cleaning, storing water and various pumping equipment. At the same time, filtration is carried out not only in the fence, but also in the outermost water supply system. Depending on where the water will be used, there are several types of outdoor water supply.

• Technical. It is intended exclusively for production facilities. Often, in order to save money, only partial cleaning is installed in technical water pipes, and the processed resource can be reused.
• Fire department. It is used for fire extinguishing systems. Such a network is additionally supplied with special equipment and hydrants. Usually, fire water supply is made dead-end, which allows it to be combined with household and technical supplies.
• Household. The transported water in such a water supply system is used for drinking and is thoroughly cleaned.

internal system

The water supply also has an internal system, consisting of a network of pipes passing inside the building and leading communications to water intake points. Since the external pipeline can have different pressures, internal water supply is arranged in two ways.

• No booster pumps. The water supply in this case is carried out due to the pressure in the external network, and the water supply includes an inlet, a water meter, pipes, a riser and a supply line. This type of supply is ideal for both a private house and city apartments. It is characterized by simplicity, it does not have any additional devices, except for the pipeline.
• With periodic or permanent deposits. Such a system is chosen when the external network is not provided with the necessary pressure for transporting water, or if it is necessary to supply it to high and remote water intake points. As a rule, water supply with pumps is installed in large buildings with a height of more than 50 m, hotels, holiday homes and industrial facilities.

In order for water to flow to consumers uninterruptedly, in addition to pumping units, the water supply system is supplemented with special tanks in which its supply is stored. The volume of tanks is determined depending on household needs, usually their capacity is calculated for 20% of the daily consumption.

Water tanks are the main components of the internal water supply system and are equipped with special pipes and valves. They are recommended to be placed in a well-lit and ventilated room.

If the project provides for zonal supply, then each site must have individual trunk lines, they are usually laid in the technical floors. Inside the building, the water supply network is made open with divorces. In some cases, hidden installation of pipes is also used, located in the shafts and furrows of the walls. To do this, connections are fixed at the installation sites of the reinforcement, and inspection hatches are fixed.

In addition, internal systems must be laid at a slope of 0.002-0.005, this will ensure the withdrawal of water from the mains to suitable pipes and appliances. If the communications are located at the lower points, then it is desirable to make a descender.

During the installation of the internal water supply, attention must be paid to the installation of stop valves. It is placed on connections to faucets, toilet bowls, flush cisterns and wash basins.

Pipe materials

When installing a water pipe, it is important to pay attention to the choice of material from which the pipes are made, since this will not only affect the cost of their installation, but also the service life. In order for the systems to reliably serve for more than a dozen years, during the purchase of pipes, it must be taken into account that they will be subjected to pressure and the chemical effects of water. Therefore, it is recommended to give preference to a durable and reliable material. To date, several types of pipes can be found on sale.

Copper

Such pipes are widely used in various engineering communications, including water supply. The main advantages of copper pipes include:

• high resistance to pressure;
• low and high temperatures;
• no deformation during heating;
• this material provides the line with durability;
• spectacular appearance.

As for the disadvantages, such systems:

• roads in the installation;
• their installation is laborious and requires special soldering technologies;
• if during operation the copper system leaks, then the damaged area must be completely cut out and replaced with a new one.

As a rule, copper water pipes are used for distilled water, as they tend to combine with toxic elements.

Chlorinated water adversely affects the physical characteristics of copper. Copper systems are also rapidly destroyed by stray current.

metal-plastic

They consist of a thin metal tube, covered on the outside and inside with layers of plastic. The advantages of such water pipes are many:

• they have a small diameter;
• easy to repair;
• easy to install;
• tolerate temperature changes very well.

But when choosing the installation of communications from metal-plastic pipes, it is worth considering that they require regular maintenance, are expensive, are afraid of shock and can collapse under the influence of ultraviolet rays.

Steel

Depending on the coating material, products are divided into galvanized and uncoated. The installation of such a water supply system is carried out using special threaded connections, couplings, tees or welding. Steel systems are characterized by high rigidity, strength and long service life. Despite the positive properties of these pipelines, they are subject to the formation of rust and inorganic deposits inside. In addition, their installation is laborious.

Galvanized

Giving preference to this type of pipes, it is important to carefully seal the joints when installing them. This can be done with linen, pre-impregnated with drying oil or paint. Threads must not be processed with synthetic solutions. The advantage of galvanized pipelines is their affordable price and easy installation, the disadvantage is a short service life.

Plastic

They are a good material for the construction of water pipes, as they:

• durable;
• do not corrode;
• have low thermal conductivity;
• light weight.

Plastic systems can be laid with a hidden method. Installation of pipes is quick and easy, but they cannot be used to supply hot water.

HDPE pipes

They are made from low-pressure polyethylene, so they are durable and are excellent for supplying both industrial and drinking water. Such pipes are popular in modern construction, because they have high elasticity and resistance to freezing. At low temperatures, they do not burst and allow you to transport both cold and hot water. In the system, pipes are connected by welding or soldering, installation is easy, since polyethylene bends well.

PVC

Unlike other types of material, these products are characterized by greater rigidity, due to which they are widely used for laying open and closed water supply lines. Pipes are suitable for transporting not only hot and cold water, but also for heating systems, they have a neat appearance and high strength. Pipes are inexpensive, they are connected by gluing and using fittings. There are no visible flaws in polyvinyl chloride.

Polypropylene

In terms of their technical properties, they are in many ways similar to polyethylene pipes, but they are much cheaper and are connected by welding. In addition, such systems are durable, strong, meet all building standards and requirements, but during their joining, you need to pay attention to the quality of soldering, otherwise leakage is possible.

Water treatment facilities

The water pipeline provides transportation of water to the consumer from various natural sources, which may contain organic and mineral elements in a dissolved, colloidal or suspended state. In order for the water quality to meet all standards, during the installation of communications, treatment facilities are additionally built. The most common options are small gravity water treatment plants. Most often they can be found in urban water supply systems.

To supply water directly to places of consumption (industrial enterprises, residential buildings, etc.), an external water supply network is equipped. The supply of water to the points of water intake inside the building is carried out through an internal water supply. According to the configuration in terms of the external water supply network, they are divided into ring (closed) and dead-end (branched).

Ring networks provide uninterrupted water supply, but they require a large number of pipes, fittings and fittings than for dead ends.

Dead end networks used for water supply of small objects, as well as during interruptions in water supply and in cases of accidents.

In the external water supply network, main (main) and distribution (secondary) lines are distinguished. A separate water supply is arranged for technical water, because the connection of drinking and technical water supply is not allowed.

Tap water from the external network under pressure enters the internal network through a water inlet laid in the ground. It is a pipeline branch from an external water supply to a water meter unit or shutoff valves inside the building.

External water supply networks are laid in the ground. In some cases (permafrost areas), water supply is carried out on the surface of the earth on supports and is necessarily thermally insulated.

When laying a water pipeline in the ground, the depth of the pipes depends on the depth of freezing of the soil, the temperature of the water in the pipes and the mode of its supply. For main pipelines with a strictly defined mode of operation, the laying depth is calculated. In all cases, the depth of the pipe should be greater than the calculated depth of soil freezing by 0.5 m from the bottom of the pipe, taking into account possible external loads on the ground surface.

Water lines are laid according to the terrain with a constant depth of laying, as well as with a slope on level ground. The slope provides the possibility of emptying the system and the release of air at the highest points of the water supply (through the plungers).

Examination ticket No. 16.

1. Translucent coating structures. Types of coatings, their scope. Examples of architectural solutions.

2. Buildings of catering establishments. The composition and layout of the premises of buildings of catering establishments.

3. Sewer system. Classification. Internal sewerage. External sewerage.

Translucent coating structures. Types of coatings, their scope. Examples of architectural solutions.

Structures enclosing buildings from above refer to coatings, the main types of which are:

a) attic pitched roofs;

b) combined coatings.

Attic pitched roofs are usually made in the form of inclined planes - slopes, covered with a roof made of waterproof materials.

Coverings with a roof slope of up to 2.5% are called flat. Flat coatings, the surfaces of which are used for playgrounds, summer restaurants, cafes, outdoor cinemas, sports grounds, etc., are called exploited flat or terraced coverings. Pitched attic roofs are used in the construction of low-rise buildings of III and IV classes in rural areas, in villages, small and medium-sized cities. Flat terrace coverings are used in buildings of I and II classes and in buildings of increased capital. The terrace covering is decided as an attic or non-attic with a slab floor.

Over buildings of small width are often arranged lean-to roofs. The roof of a building with water flow on both sides is called gable.

hipped roof square or multifaceted in terms of the building has 4 triangular slopes - hips. A gable roof, completed with hips at both ends, is called hip. If the inclined slope does not cut off the entire end of the gable roof, but only its upper or lower part, then the incomplete end slope is called a half-hip, and the roof is called half hip.

In the mass construction of multi-storey residential and public buildings, combined coatings of various types are used:

Non-ventilated combined roofs;

Partially ventilated combined roofs;

Combined roofs ventilated by outside air.

In buildings with rooms on the upper floor that have a normal humidity regime, non-ventilated coatings can be used. Above rooms with high humidity, ventilated and partially ventilated coatings are arranged. Above wet rooms (baths, pools, showers, etc.), combined roofs are not allowed.

To increase the intensity and uniformity of daylight illumination of exposition halls, exhibitions and museums, trading floors, covered landing stages of railway stations and similar public facilities located in buildings of a large area or large width (depth), “overhead light” is arranged in the coatings, i.e. . skylights or entire areas - glazed covers. A completely translucent coating in design, construction and operation is a complex structure. Separate lanterns-superstructures of various shapes in plan and section are used more widely: one-sided and two-sided, "anti-aircraft" lanterns, light shafts and other light openings. Glazing of skylights is installed in bindings or on crates of various types, based on special structures - superstructures, installed, in turn, on load-bearing elements of the coating (beams, trusses, frames, frames of spatial systems, etc.) The only exceptions are windows anti-aircraft lighting, which rest on a frame framing holes in the ribbed deck panels or in the spatial shells of the cover.

External, top, glazing, protecting the room from atmospheric precipitation, is arranged in steel bindings with a slope of 45 to 90 o. ordinary or reinforced glass is supported by edges wrapped in rubber gaskets on steel tauriki and fastened with steel spring clamps, screws and putty or special metal fasteners - glazing beads. In order to avoid water leakage in the horizontal joints, the panes are overlapped and fastened to each other and to the horizontal profiles with clamps made of strips of galvanized roofing steel.

Antiaircraft spotlights arrange in the form of tents and domes made of glass or transparent plastic. Such lanterns usually cover a square opening in the pavement measuring 1.5x1.5m or a round opening with a diameter of 1.5m or an elongated opening 1.5x5m, the size of which corresponds to the dimensions of the decking panel.

Second glazing necessary to create an air heat-shielding layer. With double glazing of light lanterns, the second glass is made with a small indent from the outer one or with a significant indent with a slight slope for the condensate slope to the hanging grooves. The second glazing should be deaf and as tight as possible, which is why it is carefully coated with putty. In skylights, the second glazing can be made flat or in the form of the same cap as the outer one.

third glazing- an element of the architectural solution of the hall, providing light scattering of direct sunlight and protecting the room from condensation drops. The third glazing, according to the constructive solution, is a translucent version of the suspended ceiling with its pendants and guides, supplemented with bindings for laying the filling - glass, which is laid “dry” on the slabs without putty with rubber gaskets so that it does not rattle.

2. Buildings of catering establishments. The composition and layout of the premises of buildings of catering establishments.

Catering establishments (PP) can be designed: - in separate buildings specially designed for catering establishments (from 100 places and more); - as part of public and shopping centers, market complexes, at railway stations; - as built-in or attached to the areas of residential and public buildings, including located in underground spaces. PP are subdivided into blanks with a full technological cycle for processing raw materials and preparing products; pre-cooking - with an incomplete technological cycle. All the types under consideration are divided into two main groups according to the forms and methods of serving visitors: enterprises serving visitors through waiters, and enterprises operating on the principle of self-service.

Accommodation Requirements. The land plot is divided into two zones: for visitors (organization of visitors' recreation and available places for eating outdoors) and utility (unloading areas). It is necessary to provide parking lots for cars on the site, they should be located at a distance of no more than 150 m from the building of the EP enterprise.

Space planning solution. There should be a clear zoning and convenient functional and technological interconnection of production corridors with the exception of human and cargo flows. Production cycle: reception and storage of semi-finished products and raw materials, heat treatment and presentation of dishes, product sales and customer service. The following groups of premises correspond to this cycle:

1. Premises for visitors (a vestibule with a wardrobe; washrooms, latrines; dining rooms; buffet; premises for the sale of meals and semi-finished products at home) These premises can be defined as commercial, and all the rest - non-commercial. The height of the floor is 3.3 m, with a large capacity of the trading floor - 4.2 m. The determining factor in the design of dining rooms is the form of service. With self-service - distributing lines. Distribution lines are recommended to be separated from the dining hall by decorative partitions. Distance 0.9 m when visitors pass in one row; 1.2 m if in 2 rows; the width of the working area behind the technological distributing line is 1 m. The area of ​​the dining room is accepted according to the norms.

2. Production premises (manufacturing workshops: hot (kitchen), cold, meat and fish, confectionery, vegetable, pie; distributing; washing kitchen and tableware; bread slicer) The location of the workshops should ensure the sequence of processing products. from two or more sides - at least 3 m. It is allowed to place in the same room washing canteens, kitchen utensils, containers of semi-finished products: in this case, the washing rooms are separated by barriers at least 1.6 m high. The washing room should have free access from the hall and from the distribution conveyor .

3. Premises for receiving and storing products (loading, storage rooms: a pantry for dry products, vegetables, a pantry for inventory and containers; refrigerated chambers) must be designed as a single unit that has a connection with freight elevators and communication with other premises through corridors. An unloading platform is located in front of the loading room. Warehouses are located in the basement, basement. Premises for storing products should not be walk-through, and should not be located under washing and lavatories. Cooled chambers are placed in the form of a single block with an entrance through a vestibule.

4. Administrative and amenity premises (office premises, office of the director and accountant, staff premises, medical office, dressing rooms, showers and sanitary blocks for personnel). Should be placed separately from other rooms. Stairs for personnel are located taking into account their use for the evacuation of visitors.

Composition schemes: centric (service premises are located in the center of the building, and dining rooms are arranged around the perimeter around them), frontal (retail premises are located along the longitudinal axis of the building parallel to non-retail premises), deep (non-retail premises are located behind the retail premises in the depths of the building, the scheme is used for small businesses) , corner (non-commercial premises, located in one of the corners of the plan, are adjacent to the dining room from two sides, while two options are possible: the dining room occupies the outer or inner corner).

The purpose of external water supply and sewerage networks (abbreviated NVK) is to provide residents and enterprises with water. They are also responsible for the subsequent disposal of waste water resources (liquid household waste, sewage, etc.). External water supply networks are not an integral part of the internal communications of buildings, they are laid outside them, provide access to a water source, a sewer reservoir. In St. Petersburg, the design and subsequent installation, commissioning of the NVK is carried out by North-Western Engineering Center LLC.

In the event that a new building is to be erected, the external water supply and sewerage networks are initially designed together with the internal network. All design work is carried out only in agreement with the state authorities - SUE "Vodokanal" (operating organization). Also, certification of the finished project is carried out by organizations such as the local traffic police, the Office of Gardening and Parks and Rospotrebnadzor.

Design of external plumbing systems

However, water supply and sewerage systems can also be installed in old buildings as part of their repair and reconstruction. If necessary, it is provided, among other things, the removal of NVK outside the zone built up with houses. The company "Engineering Center North-West" carries out all work on the design and installation of external water supply and sewerage, guided by the requirements of the current building codes and regulations (SNiPs). The list of services offered by North-West Engineering Center LLC includes:

1. NVK design works;
2. Their subsequent coordination and certification in the operating organization;
3. Selection and supply of components necessary for the work - equipment, materials, etc.;
4. Works on the actual installation of the NVK system;
5. Subsequent commissioning;
6. Commissioning.

Outdoor water supply networks

The modern water supply system is a complex network, the basis of which is the pipeline. The main task that falls on external water supply networks is the transportation of water from a source (storage, reservoir, well) to the consumer. There are two alternative ways of laying pipes - above ground and underground. The first of them is cheaper, laying works take much less time, earthworks are minimized. The pipeline itself is elevated above the ground on supports, it is necessarily protected from frost by a heat-insulating material. However, if the water pipeline project involves crossing the main, its laying is carried out through an underground trench or tunnel.

The components of the external water supply network are the structure on which the water intake is carried out. It is necessary to equip such components as cleaning products, water storage facilities, pumping equipment. The filtration system is equipped not only with water intake, but also with the external water supply system itself.

Types of outdoor water supply

Depending on the method of using the water transported to the consumer, water supply systems are divided into the following types:

1. Technical - water is intended exclusively for industrial purposes, not suitable for domestic use, drinking. In order to save, often, technical water supply networks are deliberately adapted for partial purification and reuse of waste water resources.
2. Fireman - the supplied water is used in fire extinguishing systems, supplied with a hydrant or other special equipment. There are options when, in order to save on laying work, the fire system is made dead-end or combined with technical or domestic water supply systems.
3. Household - the supplied water is intended for domestic use, including drinking. In this case, water purification is given paramount attention.

External sewer networks

When equipping external sewer networks, the system is formed using a standard set of components - wells, pipelines, collectors. In the event that the system being laid is of an autonomous type, it is also supplemented by a septic tank and other treatment facilities.

Depending on the purpose of the external sewer network, only the functions and performance of an individual element or several change. In total, the following types of networks are distinguished:

• Production (K3);
• Stormy (K);
• Household (K1).

At the stage of designing a sewer network, such features as soil characteristics (depth of freezing, groundwater), terrain features (relief, other laid communications), intensity of its operation (periodic or round-the-clock mode), estimated load on the system are fully taken into account. Last but not least, the cost of designing and building a network, its reliability and durability are taken into account.

Types of external sewer systems

External sewer networks can be of two types: pressure and gravity. The latter variety is much more common, the flow of waste water to the drain is provided by a certain slope of the pipelines, equipment for creating pressure in the system is not needed.

In a pressurized external sewer system, on the contrary, no slope is created, and equipment for creating pressure is required to be installed.

Regardless of the type of sewer network, North-West Engineering Center LLC can lay it in one of two ways - open and closed. The open method is less laborious, it involves excavation and laying of a pipeline (polyethylene, polypropylene, cast iron) on special sand preparation in a trench, followed by backfilling with sand (and its layer-by-layer tamping, which prevents pipe displacement) and soil removed from the trench. The main task when laying an external sewerage system in an open way is to observe the slope, join the segments of the pipeline, seal the sections of the entrances to the wells with protective bushings. It may also be necessary to carry out work on the lining of wells. An alternative closed method (performed by the horizontal and inclined drilling method) is used less frequently, for example, when there are highways, green spaces, roads, etc. on the way.

The device of external sewerage networks

Waste water can enter the external sewer system both through a single (common alloy) and through separate pipelines (sewage, rainwater, etc.). If necessary, pumps called sewage pumping stations (SPS) can be used to create pressure. After that, the waste water is either sent directly to the central sewer, or it is purified through a septic tank and reused (for industrial purposes) or drained into a reservoir.

Water supply and sewerage of construction sites is the most necessary invention of man.

Man is designed in such a way that he cannot do without water. At all times, people inhabited places near rivers, dug wells to gain access to this vital fluid. Subsequently, water supply systems began to be designed, which is necessary for human life, recreation and work. These systems must ensure high-quality uninterrupted supply of water in the required quantities and at any time, and comply with the SP Water supply to external networks and structures.

Simultaneously with water supply systems, sewage systems for receiving and processing water and human waste have also progressed.

Rules for laying communications

In order for people to live comfortably, household amenities should be located in the room where they are. Therefore, in addition to piping inside the building, the object must be connected to external communication networks. As in any locality where the construction of the facility is taking place, SNiP are a prerequisite for providing water and sewerage. Water supply external networks and structures:

• permission and project for this type of construction work with the laying of external communications and water supply entry points to the house for connection to the internal plumbing network, as well as the sewerage outlet connected to the cleaning system;
• compliance with the requirements for earthworks, control over hidden works and execution of technical supervision acts;
• compliance with the requirements for network materials, their quality; networks must guarantee trouble-free operation of water supply and sanitation, correcting faults will lead to additional costs for the developer.

Such serious requirements are due to:

• compliance with high-quality installation of networks and subsequent safe operation;
• financial savings and trouble-free operation of the external water supply and sanitation network;
• protection against damage to other communications laid in the ground, where work is carried out on laying networks;
• the terms of environmental laws that aim to protect groundwater;
• compliance with sanitary standards that do not allow polluting the areas where the construction site is located;
• building regulations.

Main stages of work

The general stages of installation of external engineering networks for supplying water and draining waste water after the execution of project documentation and permits include:

1. Ground works for laying pipes.
2. Foundation device for laying pipes, backfilling the bottom with sand.
3. Installation of pipelines in trenches.
4. Installation of pipes by piercing the soil and horizontal drilling if it is impossible to dig a trench (under the road).
5. Installation of reinforced concrete, brick wells, chambers.
6. Installation of control and shut-off valves, fire hydrants and columns.
7. Backfilling the network with safe material, sand with compaction.
8. Restoration of the territory in the area of ​​construction works, landscaping.
9. Registration of acts of work at all stages.
10. Preparation and connection to the central communications network or to internal plumbing wiring in the house with individual water supply and sanitation.
11. Preparation of a package of technical documentation and delivery of a construction site.

External water supply networks

Water supply systems are centralized in the form of an extensive city network, and autonomous if there is no central network for supplying water to houses. They must meet the requirements of SNiP External water supply networks.

Central networks consist of the following elements:

• water intake (reservoir, lake, river, well);
• stationary complex;
• pumping station to provide the necessary pressure;
• wells, places of connection of objects and shutoff valves.

Types of autonomous water supply

If there is no central water supply network nearby, and there is no connection to it, then water supply can be provided as follows. Drinking water can be delivered in containers for cooking and drinking. This is a temporary option for a transitional period until a permanent reliable water supply to the building is established.

You need to know that there is water everywhere in the earth. It does not depend on the location of your place. The only question is the depth of the layers of water and its quality. To get water and raise it to the surface, it is necessary to build a well or a deep well.

Outdoor systems - water supply and sewerage

There are many types of sewer networks used to drain wastewater from structures and buildings. When developing a project for a construction site, it is necessary to take into account SNiP Water supply and sewerage external networks:

• purpose of the object: economic object or residential building;
• seasonal, episodic, continuous operation of the house and sewerage networks;
• system load, volume of drains, number of plumbing fixtures installed in the house, number of people living;
• the terrain where the building is located;
• system cost;
• system design together with the outlet pipeline;
• a system for processing, receiving and utilizing wastewater;
• ratio of productivity, quality and price;
• equipment, components and materials;
• wastewater treatment quality;
• service and guarantee of reliable operation.

Types of receiving sewage equipment

For an occasional or seasonal stay in the house, it is often enough to mount a dry closet. But this system is not able to ensure the removal of drains from the laundry room, shower room and kitchen. To do this, mount different containers for collecting wastewater. The advantages of such receivers include mobility, compactness and low maintenance.

For a long stay in the building, external sewage systems are installed - a cesspool, a waste tank, a septic tank, a deep cleaning system.

Cesspool for sewage and waste

The type of external sewage used earlier in the form of a cesspool was a good device where the construction of buildings was carried out, and there was no central sewerage. Today it is difficult to obtain permission to connect a new house to the existing sewerage system in a community. Therefore, such a device as a cesspool worked for a long time due to the simple structure, cheap maintenance and long-term operation.

In the modern period, a cesspool is sometimes built outside the city, near houses where people live seasonally. With the emergence of a large number of plumbing fixtures in homes and significant water consumption for various needs, the cesspool can no longer cope and needs to be cleaned frequently.

An alternative to pits - septic tanks

These are autonomous treatment plants and facilities, both industrial and home-made.

The following types of septic tanks have become the most popular:

1. Purifying type. They make it possible to collect and process wastewater, defending them in chambers with the help of bacteria.
2. Cumulative. They are made in the form of ordinary large tanks of different volumes, accumulating and storing wastewater until it is removed by special machines.

Homemade septic tanks are a system of several chambers in which solid waste is settled. According to the number of chambers, they are two or three-chamber. Tanks are made of concrete rings, bricks or monolithic. A mandatory requirement for septic tanks is tightness to prevent the entry of microorganisms into the soil and into the external environment.

Arrangement of septic tanks

For self-arrangement of a septic tank, the following factors must be considered:

• type of soil in the territory;
• the smallest distance from water intake on clay soils, as well as heavy soils - not less than 30 meters;
• on sandy and sandy soils, the distance from the water intake is at least 60 meters.

Work is carried out in the following order:

• 1. Digging a pit of the required size.
  2. Spilling the bottom with layers of rubble and sand.
  3. Reinforcing mesh laying, concrete pouring.
  4. Arrangement of receiving chambers, formwork, pouring of the wall with reinforcement, installation of concrete rings.
  5. Sealing seams and joints.
  6. Connecting pipes to a septic tank from an external sewer.
  7. Arrangement of the locking device of the cameras.

Often a septic tank is equipped with a wastewater treatment device; only partial cleaning takes place in the sedimentation tanks. A filtration system is installed, consisting of drainage pipelines under a slope. Water through these pipes from the septic tank is distributed through the filter, and penetrating through the soil, it is purified.

Industrial cleaning

Such systems are made in such a way that they are easy to install, they are reliable in operation and do not pose a danger to the external environment. The industry produces a large number of different designs, according to the degree of purification, cost and other characteristics. Usually, firms install and configure their products themselves, and also give warranty certificates for equipment.

In areas where groundwater is at a shallow depth, it is impossible to install conventional septic tanks. Otherwise, you will often have to pump out drains with a special machine. In such a situation, the best option would be to install a deep cleaning system.

Such stations are highly efficient compared to a septic tank, and serve for large buildings. This equipment assumes a continuous supply of their electrical energy for the normal functioning of high-quality cleaning. The stations make it possible to purify wastewater by 98%, use reliable membranes and comply with SNiP Water Supply and Sewerage.

A good indicator of wastewater treatment equipment is that the system is a short time without drains. With a new intake, the process of biochemical reactions is restored for deep purification of wastewater coming from the public sewer.

List of pipes and accessories

Conclusion

In regulatory documents, you can find all the necessary provisions on external and internal communications and pipelines. This document makes it possible to prevent various errors in the construction of important facilities.