2.4 pipe diameter

The unit of pipe diameter shall be millimeters.

2.4.2 The expression of pipe diameter shall meet the following requirements:

The pipe diameter of water gas transportation steel pipe (galvanized or not), cast iron pipe and other pipes should be represented by the nominal diameter DN (such as DN 15, DN50);

The pipe diameter of seamless steel pipe, welded steel pipe (straight seam or spiral seam), copper pipe, stainless steel pipe, etc. shall be expressed as external diameter D× wall thickness (such as D 108×4, D 159×4.5, etc.). );

For reinforced concrete (or concrete) pipes, clay pipes, acid-resistant ceramic pipes, cylindrical tile pipes, etc., the pipe diameter should be represented by the inner diameter D (such as D230 and D380);

2. 4. 3 1 pipe diameter marking method shall meet the following requirements:

For a single pipe, the pipe diameter shall be marked, as shown in Figure 2.4.3- 1. Plastic pipes, pipe diameter should be expressed according to the method of product standard; When nominal diameter DN is used to indicate the pipe diameter in the design, if there are more than two pipes with nominal diameter DN and corresponding product specifications, the pipe diameter shall be marked as shown in Figure 2.4.3-2.

What kind of pipes should be used for rainwater drainage pipes in high-rise buildings? Code for Design of Building Water Supply and Drainage (GB 500 15—2003) stipulates that:

4.9.26 The selection of rainwater drainage pipes shall meet the following requirements:

1 gravity flow drainage system Multi-storey buildings should use building drainage plastic pipes, and high-rise buildings should use pressure-bearing plastic pipes and metal pipes.

What are the basic principles of layout and laying of building drainage pipes? The distance between sanitary ware and drainage pipe should be the shortest, and the pipe turns should be the least.

The drainage riser should be close to the drainage point with the largest displacement.

Overhead pipelines shall not be laid in production workshops, food and precious commodity warehouses, ventilation rooms, power distribution rooms and elevator rooms with special requirements for production technology or hygiene.

Drainage pipes shall not pass through settlement joints, expansion joints, deformation joints, flues and air ducts.

Buried drainage pipes should not be arranged in the foundation that may be crushed by heavy objects or pass through production devices.

Drainage riser should not pass through bedrooms, wards and other rooms with high requirements for hygiene and quietness, nor should it be close to the inner wall adjacent to the bedroom.

Drains should not go through windows and closets.

Plastic drainage risers should be avoided in places vulnerable to mechanical impact. If it is unavoidable, protective measures should be taken.

Plastic drainage pipes should be avoided near heat sources. If it is unavoidable, and the heating temperature of the pipeline surface is greater than 60℃, heat insulation measures should be taken. The clear distance between the plastic drainage riser and the edge of the household cooker shall not be less than 0.4m

If the external surface of the drainage pipe may be dewed, measures to prevent dewing should be taken according to the nature and use requirements of the building.

—— Excerpted from Zhulong. com

What principles and requirements should be paid attention to in the layout and laying of drainage pipes inside buildings? The layout and laying of drainage pipes in buildings should meet the requirements of smooth drainage, good hydraulic conditions, convenient maintenance, complete production and use, long service life, prevention of water quality and environmental pollution, economy and beauty.

Precautions for internal drainage pipeline:

Pipeline installation: before installation, internal dirt and sundries must be removed to prevent blockage.

2. Fabrication and installation of pipe supports: blanking and welding shall be carried out in strict accordance with the requirements of construction drawings. After anti-rust treatment, the pipe support should be installed on the load-bearing structure, with correct position, flat and firm burial and close contact with the pipe.

3. Installation of water supply and drainage pipes: the horizontal water supply pipe should have a slope, and the slope drainage device: the drainage pipe diameter and minimum slope should be constructed in strict accordance with the design requirements.

4. Pipe connection: the water supply pipe is made of galvanized steel pipe with threaded connection; Indoor drainage pipes and outdoor pipes adopt drainage cast iron pipes and asbestos cement joints.

5. Anticorrosion: Exposed galvanized steel pipe

What are the installation points of water supply and drainage pipes in high-rise buildings? Because there are many stories in high-rise buildings, the building structure is complex, and the hydrostatic pressure in high-rise water supply pipes requires high strength of pipes and fittings, noise prevention and earthquake prevention, so the requirements for pipe supports and pipe interfaces are very strict.

(1) Installation of pipeline in tube well

There are many water supply and drainage pipes in high-rise buildings, including domestic water supply pipes, fire water supply pipes, sewage drainage pipes, ventilation pipes, hot water pipes, return pipe pipes and reclaimed water pipes. The risers of these pipelines are mostly laid in the tube well and vertically fixed in the tube well through supports, supports and pipe clamps. , each layer is connected with branch pipes or horizontal pipes.

Generally, the pipe installation in the tube well is carried out from bottom to top, and the elevation and direction of the branch pipe (outlet) on the riser should be accurate to ensure the connection of the branch pipe. The installation of all kinds of pipes should be carried out in the order of coarse before fine, small diameter to large diameter, pressure pipe to gravity pipe.

There are many floors in high-rise buildings, and the workload of pipeline installation is heavy. In order to speed up the construction progress, prefabrication and on-site assembly can be adopted. Before pipeline prefabrication, the actual installation size must be measured on site, and the pipeline processing diagram should be drawn before prefabrication. Usually, a model room can be installed on the standard floor first as the standard for pipeline prefabrication and installation.

(2) Installation of water supply system

High-rise buildings usually need to be equipped with pools, pumps, pneumatic tanks and other devices.

When the pipe diameter of water supply pipeline in high-rise building is DN≤ 100mm, galvanized steel pipe shall be used for threaded connection; DN> 100mm, which can be connected by seamless steel pipe flange. The branch pipe can be a water supply plastic pipe or a copper pipe.

When installing risers, each floor should be equipped with pipe supports. The installation is firm and reliable, preventing the pipeline from sinking and causing dislocation and water leakage.

(3) Installation of drainage system

High-rise building drainage riser is long, and the water flow speed is fast, so the pipeline should be installed firmly to prevent accidents such as water leakage caused by pipeline displacement and sinking.

1. Installation of drainage cast iron pipe. When the drainage riser is located in the tube well, a firm bracket and bracket should be set up, so that the weight of the upper pipe of the pressure vessel can be transferred to the pipe wall through the bracket and bracket. Concrete piers should be set at the bottom of the joint between the riser and the outlet pipe to prevent the riser from sinking.

Drain pipe interface should be selected according to design requirements. For buildings exceeding Shang Ceng or ground instruments with seismic fortification of more than eight degrees, when the height of drainage riser exceeds 50m, Yuej flexible seismic drainage cast iron pipe interface should be selected. Please refer to the relevant installation atlas for its form.

2. Installation of rigid PVC drainage pipe. The drainage system of high-rise building adopts rigid PVC plastic pipe. The following technical problems should be solved:

(1) pipe support. Due to the high height of the riser, each floor should be equipped with a solid fixed bracket and two sliding supports.

(2) The riser dissipates energy. Because the plastic wall is smooth and the water flows fast. In order to reduce the impact of water flow in the riser and protect the water seal of sanitary ware, energy dissipators should be used.

(3) Selection of pipe fittings. Generally, the pressure resistance of rigid PVC pipe fittings is lower than that of pipes, so the drainage system of high-rise buildings should adopt glass steel pipe reinforced composite pipe fittings.

What requirements should be put forward for civil engineering specialty in the layout and laying of indoor drainage pipes? What principles and requirements should be paid attention to in the arrangement and laying of indoor drainage pipes in buildings? The layout and laying of drainage pipes in buildings should meet the requirements of smooth drainage, good hydraulic conditions, convenient maintenance, complete production and use, long service life, prevention of water quality and environmental pollution, economy and beauty.

Layout and laying requirements of drainage pipes

1, with the shortest pipeline and good hydraulic conditions. (2) The drainage riser should be located at the drainage point with the dirtiest, most impurities and the largest displacement. The drain pipe should lead to the outside in a short distance. (3) Pipes and drains should be arranged in a straight line as far as possible. When restricted by conditions, 45-degree elbow or B-shaped pipe should be adopted. (4) Sanitary ware drainage pipes and rows

The horizontal branch pipes of water shall be connected by 90-degree oblique tee. (5) Horizontal pipes and horizontal pipes Horizontal pipes and vertical pipes should adopt 45-degree tee (four-way) or 90-degree tee (four-way), and fittings such as right-angle tee or right-angle tee can also be adopted.

(6) Two 40-degree elbows or 90-degree elbows with a bending radius not less than 4 times the pipe diameter 1. 1.7 shall be used for the connection between the drainage riser and the end of the drainage pipe. When the drain pipe is connected to the outdoor drain pipe, the top elevation of the drain pipe is not

Should be lower than the top elevation of the outdoor drainage pipe, and the water flow angle at the connection point should be not less than 90 degrees. When the drop is greater than 0.3m, it is not limited by the angle. (7) When the minimum drainage inspection branch pipe is connected with the drainage pipe or drainage inspection branch pipe, the horizontal distance between the connection point and the bottom of the drainage riser should not be less than 3. O. m .(8) When the drainage riser is only provided with a top extension vent pipe (no special vent pipe), the minimum vertical distance between the horizontal drainage pipe and the riser is specified in the specification. (9) When the building height exceeds 10 floor, the lower sewage shall be discharged to the outside through a separate pipeline.

2. Easy installation, maintenance and cleaning (1). Try to avoid the drain pipe from crossing with other pipes or equipment. (2) In general, pipelines should be buried underground or laid under the ground or floor. If there are special requirements for construction or technology, it should be hidden in pipe trough, pipe well, pipe trench or ceiling, but it should be convenient for installation and maintenance. (3) The distance between the drainage riser center and the site shall be set according to the specifications.

3. Safety in production and use (1) The location of the drainage pipeline shall not interfere with production, transportation or the use of buildings. (2) The sewage outlet pipeline shall not be set on raw materials, products and devices that are burned, blown or damaged by water. (3) Overhead pipes shall not be arranged above the main and non-staple food operation rooms in bedrooms, canteens and kitchens; Nor can it be distributed in food storage rooms, halls, libraries and factories with special requirements for hygiene. (4) Overhead pipelines shall not be hung in food warehouses, precious commodity warehouses, ventilation rooms and power distribution rooms.

4. Protect the pipeline from damage (1). Buried drainage pipes should not be arranged where they may be pressed by heavy objects or pass through the foundation of production equipment. Under special circumstances, it should be handled in consultation with relevant majors. (2) The drainage pipeline shall not pass through the settlement joint, flue and wind.

Road, and shall not pass through expansion joints. When it is necessary to pass due to conditions, corresponding technical measures should be taken. (3) The clearance size should not be less than the building settlement, and generally should not be less than 0. 15m. See 4 "stagnant water" for its practice.

Drainage standard atlas S3 12, effective anti-settlement measures should be taken for drainage pipes of high-rise buildings. (4) When the drainage riser crosses the floor, casing shall be set. Cast-in-place floor slab should be reserved with holes or embedded sleeves, and the hole size should be measured.

Inches are required to be 50- 100 meters larger than the pipe diameter. (5) The minimum buried depth of the drainage pipe in the plant should be set according to the specifications. Steel pipe or cast iron pipe should be used under the rail, and the minimum buried depth should not be less than1m. (6) Cast iron drainage pipes shall be equipped with flexible interfaces under the following circumstances. (a) High-rise buildings and buildings with a building height exceeding 100m. (b) The height of drainage riser is above100m or in the seismic fortification zone of 9 degrees. (c) If conditions permit, other buildings can also use flexible interfaces. (7) Buried drainage pipes should be treated with anti-corrosion. (8) The water supply riser shall be fixed with pipe clamps, and the distance between the pipe clamps shall not exceed 3.0. The pipe clamp shall be fixed at the pipe joint with supports and hangers, and the spacing shall not be greater than1.0m.

5. Prevent water pollution

(1) The following devices and containers shall not be directly connected with the sewage (waste) water pipeline system, and indirect water pollution shall be adopted. (a) Drains and overflow pipes for rice storage (ponds) for domestic drinking water. (b) Overflow of food devices and washing devices in the kitchen. (c) Water pollution caused by medical disinfection equipment. (d) Drainage of hollow devices such as evaporative coolers and air cooling towers. (e) The basic water of the cold storage room and the moon ice in the cold storage room for storing food or drinks and the defrosting water tray of the air cooler. Indirect drainage means that the outlet pipe (mouth) of sanitary ware or water-using device cannot be directly connected with the water pipe, and there should be an air partition in the middle, so that the outlet of the drainage pipe can be directly connected with the atmosphere to prevent water quality from being polluted.

(2) The interior of the drain pipe should be kept clean. When leaving reserved holes, try to choose clean sealing materials, such as transparent glue and wooden boards. If it causes blockage, it should be cleaned up to reduce unnecessary trouble for future projects.

(3) Funnels or containers used for indirect drainage shall not spill or overflow, and shall be arranged in a position that is easy to check and clean.

(4) When the drainage pipe is buried with other pipes, the minimum horizontal clear distance is 1.0m-3.0m, and the vertical clear distance is about 0.15m-0.20m. The drainage pipe is arranged above the water supply pipe in parallel, and when the clear distance is higher than 1.5m, the horizontal clear distance should not be less than 5.0m..

How to lay 1 water supply and drainage pipes in high-rise buildings? The drainage of roof rainwater should be communicated with the architectural profession to clarify the drainage form of roof rainwater, whether it is internal drainage or external drainage. The internal drainage is designed according to the Code for Design of Water Supply and Drainage in Buildings, and the external drainage is completed by the architectural specialty.

2, domestic cold water system, need split water tank water supply, water supply pressure is usually 0.3-0.4MPa as the boundary, greater than 0.3-0.4MPa will split water tank. Piping should pay attention to the same water supply to avoid uneven water supply.

3, indoor fire hydrant system, it should be noted that when the pressure of the hydrant bolt mouth is greater than 0.5MPa, decompression measures need to be taken, and indoor pressure regulating fire hydrant can be selected. In addition, when a temporary high-pressure water supply system is adopted, a start button for directly starting the fire pump shall be set in each fire hydrant box.

4, indoor drainage, as soon as possible out of the house, indoor turn less, less confluence. Discharge the sewage into the outdoor inspection well at the first time. For the ventilation riser, it is recommended to use the annular ventilation pipe, and the first floor will drain water independently. We should also pay attention to whether there is a canteen in this kind of building. If there is a canteen, we should also consider the problem of oil separation of canteen sewage.

How to arrange and lay indoor domestic drainage pipes? The composition of the internal drainage system of the building shall meet the following three basic requirements:

First of all, the system can discharge sewage and wastewater to the outside quickly and smoothly.

Secondly, the air pressure of the drainage pipeline system is stable, and toxic and harmful gases do not enter the room to keep the indoor environment clean.

Third, the pipeline layout is reasonable, short and straight, and the project cost is low. Pay attention to the following points in the layout and laying of drainage pipes:

(1) The distance between the sanitary ware and the drainage pipe should be the shortest, and the pipe turns should be the least.

(2) Plastic drainage pipes should be avoided to be arranged near heat sources. The clear distance between the riser and the edge of the household cooker shall not be less than 0.4m

(3) It shall not be placed on the raw materials, products and devices that cause combustion and explosion when meeting water.

(4) The vertical connection between the drain pipe of sanitary ware and the horizontal drain pipe shall be 90. Inclined tee. For connections between horizontal pipes and risers, 45. Inclined tee or 45. Inclined tee, downstream tee or downstream tee should be adopted. Two 45-degree elbows or 90-degree elbows with a bending radius of not less than 4 times the pipe diameter shall be used for the connection between the riser and the end of the drainage pipe.

(5) A water seal device shall be set at the joint between the indoor drainage ditch and the outdoor drainage pipeline.

(6) The standard slope of horizontal drainage branch pipe of drainage plastic pipe should be 0.026.

(7) The minimum pipe diameter of the toilet drainage pipe shall not be less than100 mm. ..

(8) The minimum diameter of the drainage pipe in the building shall not be less than 50 mm. ..

(9) Toilets, bathrooms and other rooms that need to drain water to the ground frequently should be equipped with floor drains at the lowest place.

Why should the drainage pipes of high-rise buildings have slopes? The horizontal drainage pipes of buildings must have slopes, and different pipe diameters require different slopes. If there is no slope, how to ensure smooth drainage and no backflow?