Buildings of pumping stations are built from materials of the 1st-2nd degree of fire resistance - from brick, monolithic or prefabricated reinforced concrete. The building consists of a pumping department and auxiliary premises.
Buildings of pumping departments should be one-story, with large glazing of window openings, since windows serve not only for lighting and ventilation, but also for protecting the building structure from destruction during explosions, that is, they serve as explosive valves. Part of the pumping station with auxiliary facilities can be made in the form of a one-story or multi-story outbuilding. The annex houses the premises: transformer substation with switchboards; workshop; backup power plant; ventilation installations; office and sanitary facilities (dressing rooms, showers, washbasins, toilets, dining rooms) and others.
When installing pump units with explosion-proof electric motors, the pump room consists of one room. When using pumps driven by internal combustion engines or synchronous electric motors, as well as asynchronous electric motors of open design or with a reduced degree of protection, the pump room is built with two sections - pump and motor. In this case, the pump room is separated from the engine room by a fireproof sealed partition - a firewall. Two entrances and exits with vestibules should be provided in the pump room, one doorway with a vestibule is allowed in the engine room.
In cases where the pump room consists of two compartments, the drive shafts from the motors to the pumps pass through firewalls in sealed stuffing boxes. The figure shows one possible way to install a pump driven by a synchronous motor.
To install stuffing boxes in firewalls, openings are made, immured with steel sheets, in which holes are cut and landing flanges with studs are welded, to which gland glands are then attached.
The designs of the through stuffing box devices are mainly of two types:
- in the form of a steel boss with a flange, in which an oil seal is arranged, and bearing assemblies are mounted on special concrete supports.
console - with a cylindrical body and a flange, nodes are mounted in the console body - an oil seal and shaft supports, as a rule, with rolling bearings;
1 - pump, 2 - electric motor, 3 - starting rheostat, 4 - manual rheostat drive,
5 - stuffing box, 6 - outrigger shaft, 7 - partition (firewall)
The figure below shows the layout of a typical station with two compartments.
1,2,3 - auxiliary premises (switchboard, drivers, ventilation), 4 - centrifugal pump,
5 - gate valve, 6 - electric piston pump, 7.8 - open-type electric motors
Technological pump units in the pump room can be located in one or two rows. With a single-row arrangement of pumps, the distance between them must be at least 1.0 m (between protruding nodes). The distance from pumps to blind end and rear walls or firewalls must be at least 0,8 m. If the end walls have openings, then the distance increases and is assumed to be at least 1.0 m. The distance from the front of the pumps to the facade wall with window openings must be at least 2.0 m. A monorail with a manual hoist is usually installed in this gap for moving the units of pumping units during repair work.
With a two-row arrangement of pumping units, the distance between rows is assumed to be at least 2.0 m, the remaining gaps are the same as with a single-row arrangement of units. In this case, a monorail with a hoist is installed in the gap between the rows of pumps.
In pumping stations intended for pumping light oil products of the 1st-2nd classes (LVZH), the premises of the pumping departments are classified according to the degree of fire hazard to category A and B with an explosive zone B-1a, that is, explosive mixtures Moiyr are formed when the equipment is leaking . Therefore, electrical equipment must be used in an explosion-proof design and correspond to the explosion hazard category of the resulting mixture.
Electrical wiring must be carried out with cables and wires with rubber or PVC insulation in sealed pipes with sealed metal fittings. It is allowed to lay cables with a metal sheath openly on special mounting shelves or in metal boxes. In this case, the outer coating of cables made of combustible materials (jute, bitumen, cotton braid) must be removed.
When entering electrical wiring pipes from rooms with a normal environment or outside the building, the pipes must be hermetically walled up in the wall, and when entering an explosive room, they must have special separating fittings, which, after assembling the pipe wiring, must be filled under pressure with a special supercharger with an elastic sealing mastic on a polyethylene basis . Separation fittings, as an exception, if they cannot be installed in an explosive room, may be installed on the side of the room with a normal environment.
All types of technological equipment (pumps, pipelines) and electrical equipment (electric motors, switchboards, pipe wiring, lamps, cables, ventilation systems) must be reliably grounded. For grounding, an external ground loop is built around the pump house building, and an internal loop made of strip steel is built inside the pump room. The inner contour should be laid along the walls at a height of 200 mm from the floor, clearly visible and painted black. Both circuits are interconnected by jumpers in two places. The above technological and electrical equipment must be connected to the internal circuit. The resistance of the ground loop should be no more than 10 ohms. Protection of the pumping station from direct lightning strikes can be general from mast supports, pin or in the form of a solid metal mesh, which is laid on the ceiling under a concrete roof screed.
The lighting of the pumping station should be natural and artificial. There are two options for artificial lighting - through window openings and internal. When illuminating through window openings, it must be taken into account that for pumping stations working with oil products of the 1st and 2nd classes (flammable liquids) and belonging to zones B-1, B-1a in terms of the degree of explosion, the outer zone is considered to be explosive within 0.5 m horizontally and vertically from window and door openings. Internal wiring must be carried out in sealed pipes with metal fittings on the thread. Accordingly, indoor luminaires must be explosion-proof with a degree of protection of 1P65, outdoor - 1P64, 1P56.
Pumping stations must be equipped with ventilation, including:
- ground pumping stations working with dark oil products, natural exhaust ventilation with the installation of deflectors.
ground, semi-underground and underground pumping stations specialized in pumping oil and light oil products with forced supply and exhaust ventilation;
In pumping stations operating simultaneously with conventional petroleum products and leaded gasolines, the following shall be provided for pumping leaded petroleum products:
- separate forced ventilation with an air exchange rate of at least k = 13.5.
separate room with autonomous entrance and exit;
specialized pumping units and technological pipelines that are not connected to a common collector;
The values of the coefficients of the air exchange rate in pumping stations with a height of 6 m are taken according to the norms of SNiP 2.11.0-93 (given in the table). When lowering the height of the room, the multiplicity should increase by 16% for each meter of lowering the height of the room. The height of the premises of pumping stations should be at least 3.5 m.
Norms of air exchange rate in pumping stations
Pumping stations must be equipped with stationary fire extinguishing systems - foam extinguishing agents or steam, as well as primary fire extinguishing agents - fire extinguishers, sand, buckets, shovels, etc. Ventilation installations (fans and engines) in pumping stations for oil and light oil products must be explosion-proof execution. At the supply fans, the air intake devices are located outside the explosive zone - in the zone of clean air that is not polluted by oil vapours. The grids of the air intake devices for exhaust ventilation should be placed at the lowest point of the pump room, that is, at the level of the floor or the bottom of the channel in the case of channel laying of pipelines.
5.10.5. If, due to local conditions, it is impossible to provide pumping units with power according to category I from two independent power supply sources, it is allowed to use one source for this, provided that it is connected to different lines with a voltage of 0.4 kV and to different transformers of a two-transformer substation or transformers of two nearest single-transformer substations (with automatic backup switch device).
5.10.6. It is allowed to use a diesel power plant as a second independent source of power supply.
5.10.7. It is allowed to use a pump driven by internal combustion engines as a standby fire pump. Pumps driven by internal combustion engines must not be placed in basements.
5.10.8. The time for the fire pumps to enter the operating mode (with automatic or manual activation) should not exceed 10 minutes.
5.10.9. Pumping stations should be placed in separate buildings or annexes or in a separate room of buildings on the first, basement or first underground floor.
5.10.10. Pumping stations must have a separate exit to the outside or to a staircase with an exit to the outside.
5.10.11. The room of the pumping station must be separated from other rooms by fire partitions and ceilings with a fire resistance limit of REI 45 according to.
5.10.12. The air temperature in the room of the pumping station should be from 5 to 35 °C, relative air humidity - no more than 80% at 25 °C.
5.10.14. The station room must be equipped with a telephone connection with the fire station room.
5.10.15. At the entrance to the station premises there should be a light panel "Fire fighting pumping station" connected to emergency lighting.
5.10.17. When determining the area of premises of pumping stations, the width of the passages should be taken at least:
Between control nodes, between them and the wall - 0.5 m;
Between pumps or electric motors - 1 m;
Between pumps or electric motors and a wall in recessed rooms - 0.7 m, in others - 1 m, while the width of the passage on the side of the electric motor must be sufficient to dismantle the rotor;
Between compressors or blowers - 1.5 m, between them and the wall - 1 m;
Between the fixed protruding parts of the equipment - 0.7 m;
In front of the electrical switchboard - 2 m.
Notes:
1. Passages around the equipment, regulated by the manufacturer, should be taken according to passport data.
2. For pump units with a discharge pipe diameter up to DN 100 inclusive, it is allowed:
Installation of units against a wall or on brackets;
Installation of two units on one foundation with a distance between the protruding parts of the units of at least 0.25 m, providing passages around the double installation with a width of at least 0.7 m.
5.10.18. To reduce the dimensions of the station in terms of plan, it is allowed to install pumps with the right and left rotation of the shaft, while the impeller must rotate in only one direction.
5.10.19. In the room of the pumping station for connecting the fire extinguishing installation to mobile fire fighting equipment, it is necessary to provide pipelines with a nominal diameter of at least DN 80 with branch pipes led outside to a height of (1.35 +/- 0.15) m, equipped with GM 80 connecting heads. The pipelines must provide the greatest estimated consumption of the dictating section of the fire extinguishing installation.
5.10.20. Outside the premises of the pumping station, the connecting heads must be placed with the expectation of connecting at least two fire trucks at the same time (i.e. there must be at least two inputs with connecting heads).
5.10.21. Simultaneously with the inclusion of fire pumps, all pumps for other purposes, powered by this line and not included in the AUP, should be automatically turned off.
5.10.22. The axis mark or the pump immersion mark should be determined, as a rule, from the conditions for installing the pump casing under the bay:
In a tank (container, tank) - from the upper water level (determined from the bottom) of the fire volume;
In a water well - from the dynamic level of groundwater at maximum water withdrawal;
In a watercourse or reservoir - from the minimum water level in them: at the maximum provision of the calculated water levels in surface sources - 1% and at the minimum - 97%.
5.10.23. When determining the mark of the axis of the fire pump or the mark of the immersion of the fire pump relative to the minimum level of intake water, it is necessary to be guided by the technical documentation for a specific type of pump.
5.10.24. In buried and semi-buried pumping stations, measures should be taken to prevent possible flooding of the units in the event of an accident within the machine room at the largest pump in terms of productivity, as well as at shut-off valves or pipelines by:
Location of pump motors at a height of at least 0.5 m from the floor of the machine room;
Gravity release of an emergency amount of water into the sewer or onto the surface of the earth;
Pumping water from the pit with special or main pumps for production purposes.
5.10.25. For water drainage, the floors and channels of the machine room should be designed with a slope towards the prefabricated pit. On foundations for pumps, bumpers, grooves and pipes for water drainage should be provided; if gravity drainage of water from the pit is not possible, drainage pumps should be provided.
5.10.26. In pumping stations with internal combustion engines, it is allowed to place consumable containers with liquid fuel (gasoline - 250 l, diesel fuel - 500 l) in rooms separated from the engine room by fireproof structures with a fire resistance rating of at least REI 120 according to.
5.10.27. Vibration-isolating bases and vibration-isolating inserts in fire pumping installations may not be provided.
5.10.28. Fire pump units and modular pump units must be installed on a foundation, the mass of which must be at least 4 times the mass of the pump units or modular pump units.
5.10.29. The number of suction lines to the pumping station, regardless of the number and groups of installed pumps, must be at least two. Each suction line must be sized to carry the full design flow of water.
5.10.30. The placement of shut-off valves on all suction and pressure pipelines should provide the possibility of replacing or repairing any of the pumps, check valves and main shut-off valves, as well as checking the characteristics of the pumps.
5.10.31. The suction piping, as a rule, should have a continuous slope to the pump with a slope of at least 0.005. In places where the diameters of pipelines change, misaligned transitions should be used.
5.10.32. On the pressure line, each pump should be provided with a check valve, a valve and a pressure gauge, and on the suction line - a valve and a pressure gauge. When the pump is operating without back pressure on the suction line, it is not necessary to install a valve on it. 5.10.36. When automatically and remotely turning on fire pumps, it is necessary to simultaneously give a signal (light and sound) to the fire station room or other room with round-the-clock stay of service personnel.
5.10.37. In pumping stations, it is necessary to provide for the measurement of pressure in the pressure pipelines at each pumping unit, the temperature of the bearings of the units (if necessary), the emergency level of flooding (the appearance of water in the machine room at the level of the foundations of electric drives).
5.10.38. A visual level gauge to control the level of fire extinguishing agent in fire tanks should be located in the pumping station. In case of automatic replenishment of the tank, only automatic measurement of emergency levels with alarm output to the fire station and the pumping station is allowed.
5.10.39. Pump units and control units in accordance with GOST 12.4.009, GOST R 12.4.026, GOST R 50680, GOST R 50800 and GOST R 51052 must be painted red.
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The layout of pumping units in a pumping station depends on the number of pumps, their type, the depth of the machine room and are discussed in the following sections for specific pumping stations. However, there are general principles for the location of units and pipelines: the width of the passages between the protruding parts of the pumps is taken at least 1 m, between the units and the wall - 1 m (in buried stations - 0.7 m), between the protruding parts of the pumping units and pipelines - 0.7 m, between pipelines - 0.7 m.
The layout of the machine room is carried out in the following sequence:
1. The layout of pumping units is selected, some of which are described below in the relevant sections. Reserve units are placed according to the general rules with the workers. It is convenient to use symmetrical layouts of pumps and pipelines.
2. A scheme is drawn up for tracing intra-station pipelines: suction and pressure conduits, collectors, suction and pressure pipelines of pumps.
3. The diameters of all intra-station pipelines are determined according to the highest flow rate for each section. To determine this flow, all possible options for the operation of pumps are considered, including standby ones.
4. The locations of the fittings and fittings are outlined, then their dimensions are found according to, or adj. 6.
5. Starting from the outermost pump, a wiring diagram of the pipelines connected to it is drawn up to scale. Mounting inserts are not initially installed on these pipelines. Observing the minimum distances between units and pipelines, a wiring diagram for other pumps is built. For pumps of different brands, the length of the pipelines will be different. In order for the connecting manifolds to be located on the same axis, mounting inserts are installed on some pipelines in accordance with Fig. 3.1.
Rice. 3.1. Scheme of mutual arrangement of pumps and pipelines in the engine room: 1 - pumping unit; 2, 5, 9 - transition; 3, 6 - mounting insert: 4 - elbow; 7 - check valve; 8 - valve; 10 - tee; 11 - pressure manifold; 12 - underground channel
6. Leaving the necessary minimum distances between pumps, pipelines and walls (see above), approximately determine the dimensions of the machine room. At the same time, the position of the mounting site, the location of auxiliary equipment, for example, a vacuum pump, a drainage pump, etc., is outlined. If auxiliary premises are located in the same building as the machine room, their area should be taken into account. The resulting minimum dimensions of the pumping station should be linked to the modular system of industrial building structures described in Sec. 3.5. If the dimensions of the pumping station, taking into account the modular system, turn out to be larger in width or length than the approximate ones, the space between the pumps should be increased, which creates ease of operation. In this case, mounting inserts on pipelines are used.
When finalizing the dimensions of the pumping station, it is necessary to take into account the mutual placement of pipelines and structural elements of the building, for example, columns (Fig. 3.2).
Rice. 3.2. Scheme for determining the size of the machine room, taking into account the placement of pumping equipment and a grid of columns
7. The floor marks of the engine room and auxiliary rooms are linked. If necessary, stairs, passages, platforms are arranged. To ensure passage to any part of the machine room, transitions through pipelines are provided. Near gate valves with high flywheels, service platforms are provided at a convenient height.
The layout of the equipment should provide convenient and safe maintenance of this equipment with the minimum dimensions of the room. The following schemes for placing pumping units in the engine room are used (Fig. 4.71, a -G):
single-row with the arrangement of the axis of the units parallel to the longitudinal axis of the building;
single-row with the direction of the axis of the units, perpendicular to the longitudinal axis of the building;
double row chess;
double row symmetrical.
Rice. 4.71. Layouts of pumping units
in the engine room
The first scheme allows you to reduce the transverse dimensions of the building; at the same time it increases its length. This scheme is expedient for a small number of large units (with pumps of the type D, SE, etc.). The second scheme makes it possible to reduce the length of the building. This scheme is the most common; recommended for an increased number of large units and when installing cantilever type pumps (type K).
In the case of a large number of large units, schemes with a two-row staggered or symmetrical arrangement of these units are used.
Make-up and drainage pumps are recommended to be located in free areas of the machine room so that they do not increase the dimensions of the room.
In the case of pumping units with electric motors up to 1000 V with a discharge pipe diameter of up to 100 mm, it is allowed to install two units on a common foundation without a passage between them, as well as placing the unit against a wall without a passage between the wall and the unit.
For the installation and repair of pumping units, auxiliary equipment, pipelines and fittings, an installation site is provided in the machine room. When determining its dimensions, the dimensions of the largest of the pumping units, the dimensions of the transport for transporting cargo, the width of the passage around the unit or transport located on the installation site (at least 0.7 m), the possibility of approaching the hook of the lifting device to the unloaded equipment are taken into account.
Rice. 4.72. Determination of the minimum height of the pumping station:
H n - height of the pumping station; H mouth - the height of the installed equipment; Well - the distance from the bottom of the transported node to the point of attachment of the slings (or to the top of the node); H c - vertical projection of the length of the lines; H to - the height from the hook to the bottom of the building structure of the floor; H kr - crane height; h p - height of crane rails; h str - the distance from the top of the crane rails to the bottom of the floor building structures; h 3 - gap between the installed equipment and the transported unit
The height of the above-ground part of the turbine hall (Fig. 4.72) is determined taking into account the height of the platform of vehicles for transporting equipment and the largest dimensions of the assembled unit being transported (pumping unit, pump or electric motor). In this case, the length of the slings (at least 0.5 - 1 m), the conditions of transport of the moved unit (above the floor or above the installed equipment) should be taken into account.
The minimum distance from the moving unit to the floor or installed equipment is recommended to be at least 0.3 - 0.5 m. The distance from the hook of the lifting device to the bottom of the crane beam should also be taken into account.
The above-ground part of the engine room is made at least 3 m high.
The dimensions of the household premises of the pumping station are taken in accordance with SNiP II-92-76 "Auxiliary buildings and premises of industrial enterprises".
The dimensions of the gates (or doors) for the entry of vehicles are determined by the largest overall dimensions of the equipment or transport. The minimum width of the gates (doors) for the exit of vehicles is 2 m.
Mounting openings are provided for the installation of large blocks in the walls or in the ceilings of the pumping station. Mounting openings are made in the end wall, from the side of the possible expansion of the pumping station. The dimensions of the mounting openings are determined by the dimensions of the largest of the blocks (assemblies) of equipment and pipelines.
An example of the layout of a booster pumping station is shown in fig. 4.73.
Rice. 4.73. An example of the layout of a booster pumping station:
a - engine room; 6 - switchgear room; in- transformer; G- bathroom; 1 - booster pump; 2 - booster pump electric motor; 3 - make-up pump; 4 - feed pump electric motor; 5 - sump; 6 - suspended single-girder crane; 7 - control panel; 8 - pump house assembly; 9 - power supply cabinet for control circuits; 10 - make-up pump control cabinet; 11 - KRU cabinet; 12 - power transformer; 13 – capacitor unit
Pipeline connections are welded. Flanged connections are used at the points of connection of pipelines to pumps and flanged fittings.
The location of pipelines in the pumping station should provide free access to equipment and fittings, ease of maintenance and repair.
When laying pipelines above the floor surface, to enable passage over the pipelines, catwalks are provided.
Laying in underground channels is used in cases where the placement of pipelines above the floor causes great complications.
When laying above the floor and in the channels, the movable supports of the pipelines must be installed on reinforced concrete support pads.
The placement of movable and fixed supports should be carried out taking into account the need to unload the pumps from the forces arising from temperature deformations of pipelines, as well as from weight loads.
In places where pipelines are connected to pumps (with pipeline diameters exceeding the diameters of pump nozzles), transition pipes should be provided to ensure a smooth change in water velocity.
Length L transition pipes are recommended to be taken equal to
L = a(D1 - D2 ), (4.14)
where D 1 - pipeline diameter; D2 - pump nozzle diameter; a - constant coefficient, a = 5 ÷ 6 .
The nozzles must be installed in such a way as to prevent the formation of air pockets.
All pipelines of network water in the building of the pumping station are isolated. In this case, the temperature on the surface of the insulation should not exceed 45°.
Drainage valves are installed at the lower points of the pipelines, and valves for air release are installed at the upper points.
The fittings should be located in places convenient for maintenance. When placing reinforcement at a height of 1.4 m or more from the floor, platforms and bridges should be provided.
When designing platforms and bridges, the height above the floor of manual and electric drives of valves and other fittings should be taken into account.
All gate valves with a diameter of 500 mm and above must be electrically operated. In the case of remote control of shut-off valves, an electric actuator should be installed on this valve, regardless of its diameter.
For the use of industrial methods for the manufacture of pipelines at a plant or in procurement workshops, it is necessary to provide for the breakdown of pipelines into separate units (blocks).
Breakdown of pipelines into blocks is carried out taking into account the dimensions of the platform of railway or road transport; maximum mass of cargo moved by lifting and transport equipment of pumping stations; dimensions of mounting and door openings; the need to ensure sufficient rigidity of the block structure; conditions for performing welding work in the places where the blocks are joined.
To carry out the installation of equipment, fittings and pipelines after the erection of building structures and carrying out repair work, lifting and transport equipment is installed at pumping pumping stations.
When choosing handling equipment, the maximum weight of the installed equipment (pump, electric motor) or the weight of the unit in the assembled state is taken into account, depending on the terms of delivery. It should also take into account the possibility of increasing the weight of the cargo in case of replacing the installed equipment with a more powerful one.
With a machine room length of up to 18 m and lifting a load to a height of up to 6 m, the following types of manual handling equipment are recommended: with a load weight of up to 1 t - a fixed beam with crampons or an overhead single-girder crane; with a cargo weight of up to 5 tons - an overhead single-girder crane; with a cargo weight of more than 5 tons - an overhead crane.
In cases where the length of the machine room is more than 18 m and the height is more than 6 m, electric handling equipment should be used.
Portable tripods with hoists can also be used for mounting equipment weighing up to 500 kg.
General instructions
Pumping and blower stations
8.1.1 Pumping stations are divided into three categories according to the reliability of action, indicated in the table 17 .
8.1.2 Basic requirements for the layout of pumping and blower stations, determining the size of machine rooms, handling equipment, placement of units, fittings and pipelines, service devices (bridges, platforms, stairs, etc.), as well as measures against flooding of machine rooms halls to be accepted according to SP 31.13330.
Requirements for the layout and arrangement of sewage pumping stations with submersible pumps must be adopted in accordance with this set of rules, taking into account the specific features established by pump manufacturers.
In particular, it is allowed not to provide for the installation of backup units with their storage in the premises of the pumping station, provided that they can be replaced within 2-4 hours.
8.2.1 Pumps, equipment and pipelines should be selected depending on the estimated inflow and physico-chemical properties of wastewater or sediment, lifting height and taking into account the characteristics of pumps and pressure pipelines, as well as the order of commissioning of the facility.
The layout and piping of equipment should provide the possibility of replacing units, fittings and individual components without stopping the operation of the station. The number of standby pumps should be taken from the table 18 .
Notes
1 The capacity of pumping stations for pumping rainwater must be taken into account that low areas are not flooded with a set period of a single overflow of the network, flow regulation and an allowable pumping period.
2 In pumping stations of the first category of operation reliability, if it is impossible to provide power from two sources, it is allowed to install standby pumping units with internal combustion engines, thermal engines, etc., as well as autonomous sources of electricity (diesel power plants, etc.).
3 If it is necessary to increase the productivity of buried pumping stations in the future, it is allowed to provide for the possibility of replacing them with pumps of higher productivity or the construction of reserve foundations for installing additional units.
Table 18 - Requirements for the number of standby pumping units at pumping stations of various categories and types of pumped liquid
| Domestic and related industrial wastewater | Aggressive wastewater | ||||
| Number of pumps | |||||
| workers | reserve at the category of reliability of action | workers | standby for any category of operation reliability | ||
| first | second | third | |||
| 1 and 1 in stock | 1 and 1 in stock | ||||
| 1 and 1 in stock | 2 - 3 | ||||
| 3 or more | 1 and 1 in stock | ||||
| - | - | - | - | 5 or more | Not less than 50% |
| Note 1 As a rule, reserve pumps are not required in storm water pumping stations, unless emergency discharge into water bodies is not possible. 2 During the reconstruction associated with an increase in the productivity of pumping stations for pumping domestic wastewater of the third category of reliability of operation, it is allowed not to install standby units with their storage in a warehouse. 3 In pumping stations of domestic and industrial wastewater close to them in composition, equipped with submersible pumps of submersible and (or) dry installation of 3 or more, it is allowed to store the second standby pump in a warehouse. |
8.2.2 Pumping stations for pumping domestic and surface sewage should be located in separate buildings.
Pumping stations for pumping industrial wastewater may be located in a block with industrial buildings or in industrial premises of the corresponding category of production processes.
In the common engine room, it is allowed to install pumps designed for pumping wastewater of various categories, except for those containing combustible, flammable, explosive and volatile toxic substances.
It is allowed to install pumps for pumping wastewater in the production facilities of wastewater treatment plants.
In the machine rooms of pumping stations, the width of the passages should be taken at least:
between pumps or electric motors - 1 m;
between pumps or electric motors and a wall in recessed rooms - 0.7 m, in others - 1 m; at the same time, the width of the passage on the side of the electric motor must be sufficient for dismantling the rotor;
between fixed protruding parts of the equipment - 0.7 m;
in front of the electrical switchboard - 2 m.
Notes
1 Passages around the equipment, regulated by the manufacturer, must be taken according to passport data.
2 For units with a discharge pipe diameter of up to 100 mm inclusive, it is allowed: installation of units against a wall or on brackets; installation of two units on the same foundation with a distance between the protruding parts of the units of less than 0.25 m, providing passages around the double installation with a width of at least 0.7 m.
8.2.3 On the inlet collector of the pumping station, a locking device with a drive controlled from the surface of the earth should be provided.
At automated pumping stations, it is necessary to provide for the power supply of drives from batteries or uninterruptible power supplies.
Note - In order to avoid flooding the nearby territories of the pumping station with sewage, it is necessary to provide for an emergency discharge with an organized sewage disposal for the time of the accident to water bodies, special tanks, etc., in agreement with the sanitary supervision authorities. Actuators on shut-off valves must be sealed.
8.2.4 The design and dimensions of the receiving tanks of pumping stations should ensure the prevention of conditions for the formation of eddies (turbulence) in the flow of the pumped liquid. This can be ensured by deepening the suction pipe relative to the minimum liquid level by at least two of its diameters, but by more than the required NPSH set by the pump manufacturer, as well as by ensuring the distance from the suction pipe to the point where the liquid enters the receiving tank, or to gratings, sieves, etc. - at least five pipe diameters. When groups of pumps operate in parallel, each with a flow rate of more than 315 l / s, it is recommended to provide flow-guiding walls between them.
8.2.6 The number of pressure pipelines from pumping stations of any reliability category must be taken on the basis of technical and economic calculations, taking into account the possibility of an emergency release (bypass), control capacity, use of the storage capacity of the supply network, the allowable reduction in water consumption according to SP 31.13330.
If the number of pressure pipelines from the pumping station of the first category of reliability is two or more and if their length is more than 2 km, switching between them should be provided, the distance between which is taken based on the gap in the event of an accident at one of them 100%, and in the presence of an emergency release - 70% of the calculated expense. In this case, the possibility of using standby pumps and switching between pipelines should be taken into account.
Note - Pipe fittings, devices for damping hydraulic shocks, plungers must be designed for the passage of wastewater of the appropriate composition.
8.2.7 The pumps should be installed under the filling of the pumped liquid or with the liquid boost (according to the pump rating data). If the pump housing is located above the design level of wastewater in the tank, measures must be taken to ensure the start-up and cavitation-free operation of the pumps. Installation of pumps for pumping sludge and sludge should be only under the bay.
8.2.8 The speed of movement of sewage or sediments in the suction and pressure pipelines must exclude the deposition of suspensions in them. For domestic wastewater, the lowest velocities should be taken at least 1 m/s.
8.2.9 In pumping stations for pumping sludge and sludge, it is necessary to provide for the possibility of flushing suction and pressure lines.
In some cases, it is allowed to provide mechanical means for cleaning the sludge lines.
8.2.10 Pumping stations with submersible pumps of a submersible installation must be designed in accordance with the recommendations of manufacturers, taking into account their design and technological features, as well as the requirements SP 31.13330.
8.2.11 To protect pumps from clogging in receiving tanks (or in front of them), the following should be provided:
devices for retaining large suspended components transported by sewage (grids of various types, strainers, nets, etc.);
equipment and mechanisms for grinding large suspensions in the wastewater stream;
forced mixing through the use of submersible mixers and / or supply of part of the pumped wastewater into a receiving tank;
grates with manual cleaning, baskets, etc. - at pumping stations of low productivity.
8.2.12 When installing equipment, aisles with a width regulated by the supplier should be provided.
8.2.13 Retained shredded waste may be discharged back into the wastewater stream, or dewatered in appropriate equipment and transported in sealed containers to landfill or disposal.
Note - Crushed waste can be used as a filler for composting.
8.2.14 The receiving tank, combined in the same building with the machine room, must be separated from it by a blank watertight partition. Communication through the door between the machine room and the grate room is allowed only in the non-buried part of the building, provided that measures are taken to prevent sewage from entering the machine room when the network is flooded.
Notes
1 The level of door thresholds should be calculated based on the conditions for the possibility of flooding of the supply collectors when the facility is de-energized and its location on the ground.
2 To increase the degree of reliability of the pumping station, it is allowed to install submersible (hermetic) pumps in a "dry" design in the engine room and submersible pumps for emergency pumping of water from the engine room.
8.2.15 The capacity of the underground tank of the pumping station should be determined depending on the inflow of wastewater, the performance of the pumps and the permissible frequency of switching on the electrical equipment and the cooling conditions of the pumping equipment.
In the receiving tanks of pumping stations with a capacity of more than 100 thousand m 3 / day, two compartments must be provided without increasing the total volume.
The capacity of the receiving tanks of pumping stations operating in series should be determined from the condition of their joint operation. In some cases, this capacity may be determined based on the conditions for emptying the pressure pipeline.
8.2.16 The capacity of the sludge station tank when pumping sludge outside the wastewater treatment plant must be determined based on the condition of 15-minute continuous operation of the pump, while it is allowed to reduce it due to the continuous release of sludge from the treatment plant during pump operation.
Receiving tanks of sludge pumping stations can be used as water tanks when flushing pipelines.
8.2.17 Devices for sediment agitation and tank washing should be provided in receiving tanks.
The slope of the bottom of the tank to the pits is taken at least 0.1. For tanks with decreasing depth in plan and for pits, the slope of their walls to the horizon should be taken at least 60 ° for concrete and at least 45 ° for smooth surfaces (plastic, polymer-coated concrete, etc.).
8.2.18 In reservoirs for receiving wastewater, the mixing of which can cause the formation of harmful gases, precipitating or toxic substances, and also, if it is necessary to maintain independent wastewater flows, separate sections for each flow must be provided.
8.2.19 Tanks for industrial wastewater containing combustible, flammable, explosive or volatile toxic substances must be separate. The distance from the outer wall of these tanks should be at least: 10 m - to the buildings of pumping stations, 20 m - to other industrial buildings, 100 m - to public buildings.
8.2.20 Reservoirs of industrial aggressive wastewater should, as a rule, be separate. They are allowed to be placed in the engine room.
The number of tanks must be at least two with a continuous flow of wastewater. In case of periodic discharges, it is allowed to provide for one reservoir, provided that it is possible to carry out repair work.
8.2.21 It is recommended to provide for the diameter of the suction pipeline, as a rule, larger than the suction pipe of the pump.
The distance from the suction pipe of the pump to the nearby fitting (outlet, armature) must be at least five pipe diameters.
Transitions for horizontal suction lines must be eccentric with a straight top to avoid air pockets. The suction pipeline must have a continuous rise to the pump of at least 0.005.
The laying of suction pipelines between separate tanks and buildings of pumping stations should be provided in channels or tunnels with an ascent to the pumps.
8.2.22 In pumping stations, pipelines should be laid, as a rule, above the floor surface, or in channels under the floor with access to maintenance and valve control.
Laying in the channels of pipelines transporting aggressive wastewater is not allowed. The number of valves should be kept to a minimum.
8.2.23 To reduce the estimated flow rates of wastewater supplied to pressure pipelines, as well as to accumulate the flow of wastewater during accidents on them, it is allowed to install control or emergency control tanks. The optimal value of the regulated design flow should be determined by a feasibility study.
8.2.24 The design of control and emergency control tanks shall provide for the pumping of regulated flow to treatment facilities, collection and removal (or non-sedimentation) of suspended solids, washing out of settling sand, non-decaying of sewage, as well as purification of ventilation emissions.
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