Hollow wall winding pipe installation construction

2017-06-27

I. Introduction

At present, the drainage pipes used in the outdoor drainage pipe network project mainly include reinforced concrete pipes, PVC pipes, cast iron pipes, glass steel pipes and emerging hollow wall winding pipes. The hollow wall winding tube is in the 1990s in the international

A new type of plastic drain pipe that has been developed. The pipe is a new type of energy-saving high-tech product that is resistant to acid, alkali, corrosion, pressure, abrasion, non-toxic and green. It has a service life of 50 years. After comparison

The outdoor drainage pipe network project of Weihai International Commodity Exchange Center selected this pipe, which saved manpower and improved its comprehensive performance.
Second, the technical characteristics and scope of application of hollow wall winding pipe

1. Pipe characteristics

The hollow wall winding pipe uses polyethylene as the raw material for production, and is a plastic-generation steel product advocated by the state. The pipe is a hollow wall structure and is fused to one body, so that it has good impact resistance and pressure resistance. Hollow wall winding

The tube has the following excellent characteristics:

Chemical resistance: It is not corroded by sewage, waste water and chemicals, and is not corroded by decaying substances in the soil.

Impact resistance: the pipe wall is "work" structure, impact resistance, high rigidity; the hollow wall winding pipe is a flexible pipe, the extension is good, and the foundation sinking pipe will not be broken.

Anti-aging: The tube is black anti-UV formula with excellent anti-aging properties.

Light weight: Due to the hollow structure of the pipe, raw materials are saved while maintaining rigidity. At the same diameter, the weight per unit length is 1/8 of the weight of the cement pipe. Convenient construction, no need for large installation equipment, minus

Lighter labor intensity and shorter construction period.

Good drainage performance: the inner wall of the pipe is smooth, the fluid dynamic friction is small, and the flow velocity is fast. The hollow wall winding pipe is selected, and the pipe diameter of the pipe can be 1-2 pipes smaller than the diameter of the reinforced concrete pipe. Economic performance: pipe material price

Low grid, low construction, management and maintenance costs.

Pipe connection: Usually use "electric heating ribbon" or "heat shrink tape" connection technology. The pipe and the pipe are melted together to ensure the strength of the connection and zero leakage of the pipe system. Mining in this project

The "heat shrink tape" connection technology was used.

2. Scope of application

Hollow wall winding pipe can be widely used in municipal sewage, highway, rainwater discharge, farmland irrigation, and also as a buried cable casing. Pipe transportation is convenient for loading and unloading, construction is simple and convenient, and the connection is sealed.

It is an ideal substitute for cement pipes, cast iron pipes and glass pipes.



Third, the principle of the process

The inner wall of the hollow wall winding pipe is smooth, the pipe roughness coefficient is n=0.009. Under the same pipe diameter condition, the flow rate of the concrete pipe is 30% larger than that of the concrete pipe. The hot melt interface technology adopted by the pipe makes the two pipe sections connected completely melted.

One body ensures that the pipe interface will not leak. The pipe is made of 100% high-density polyethylene under hot melt conditions, which makes it have good integrity, chemical stability and long service life.

The advantage of the pipe, the project uses the hollow wall winding pipe as the outdoor drainage pipe, which is also the plastic-made steel product promoted by the state.

Fourth, the hollow wall winding tube hot melt shrinkage belt connection construction process

1. Construction preparation:

1 The design drawings and other technical documents are complete and passed the review.

2 Hollow wall winding pipe system Before the installation, the appearance and joint tolerances should be carefully checked. The dirt and debris inside and outside the pipe and pipe fittings must be eliminated.

3 When the temperature difference between the construction site and the material storage site is large, the pipe and pipe fittings should be placed on site for a certain period of time before installation, so that the temperature is close to the ambient temperature of the construction.

2. Construction process

Construction preparation → excavation and grooving → lower pipe installation → connection → water supply → acceptance

3. Technical points

(1) Excavation and slotting

1 The base elevation should be strictly controlled. Excavation is strictly prohibited. The floating soil above 0.2-0.3 m above the base design elevation should be manually cleaned to the design elevation. If the local over-excavation or disturbance occurs, it can be replaced with a natural particle size of 10-15mm.

Graded sand or medium and coarse sand and tamped.

2 If there are objects such as stones, gravel, bricks, etc. at the bottom of the trench, it should be removed to 0.2 m below the design elevation, and should be equipped with natural grade sand and gravel. The surface layer should be covered with sand; the bottom of the tank should not be soaked by water. Or be frozen.

3 In the rainy season construction, the length of the slot should be shortened as much as possible, so that the groove is fast and the backfill is fast. Once the bubble occurs, the water should be removed, and the surface layer of the base softened by the bubble should be removed, and the sand stone or medium and coarse sand should be replaced.

Do the basic processing and install it.

(2) Lower tube installation

1 The lower tube can be carried out by hand or by crane. To keep the balance of the pipe evenly distributed into the groove, it is strictly forbidden to roll the pipe into the groove from the groove side.

2 The length of the pipe can be adjusted by electric saw, but the end face should be vertical and should not be damaged.

(3) Pipe connection

The pipe connection is made by a hot melt shrink band connection. The specific construction operations are as follows:

1 Put the pipeline strictly according to the requirements of the drawings and only the slope.

2 preheating. Before the butt joint, the two pipe sections are each extended to a certain free length, and the pipe section is preheated by a special heating tool.

3 Attach the connecting tube to the tube and slowly heat it from the upper end of the tube to the tube. Heating should be heated from the middle to the periphery to avoid air bubbles.

4 gradually heat a circle, gently smooth with your hands, and stick. Then heat it again and still stroke the ring.

5 hollow wall winding pipe diameter ≥ Φ500 or more need to take two layers with outer belt, pipe diameter ≤ Φ400 only need to take a layer.

(3) The irrigation test is required after the pipeline connection is completed.

(4) Backfill

Pipe installation and backfilling after laying. Before backfilling, the debris in the trench must be cleaned up, and should be backfilled symmetrically from both sides of the pipeline, inspection wells, etc., to ensure that pipelines and structures do not generate bits.

shift. Backfills on both sides of the pipeline and within 0.5m above the top of the pipe shall not contain gravel, bricks, frozen blocks and other hard objects. After the pipeline is laid, it is necessary to build a high-grade pavement or other required pavement immediately. Correct

The requirements for backfilling compactness shall be in accordance with the relevant technical regulations or specifications provided by the manufacturer.

V. Construction precautions

1. The heating time of the pipeline and the shrinkage belt should be moderate, otherwise the connection will not be dense or charred.

2. The pipes and shrinkage belts should be heated evenly. Bake from the middle to the sides. Do not bake from both sides to avoid air bubbles.

3, the type of shrinkage belt should correspond to the pipe diameter, and the model of the belt has an impact on the quality of the interface.

4, the pipe mouth should be aligned, the pipe connection process should be careful, and avoid the interface is contaminated. It is not allowed to move the pipe within 30 minutes after the pipe connection.

Sixth, engineering cost analysis

The advantage of the hollow wall wound pipe as the drainage pipe network pipe is obvious. However, at the same time of superior performance, price is also an important factor in the selection of pipes. The hollow wall winding pipe is lower in price than the glass steel pipe; compared with the small pipe diameter PVC pipe, it is lower than the PVC reinforced pipe, slightly higher than the PVC double wall corrugated pipe, but the PVC double wall corrugated pipe has a small pipe diameter range (≤500). The performance of all aspects is slightly worse than the hollow wall winding tube; the hollow wall winding tube is higher than the reinforced concrete tube, but the selection of the tube should be comprehensively selected from the technical and economic aspects. Now compare the comprehensive cost of the Φ1000 reinforced concrete drainage pipe and the DN700 hollow wall winding pipe used in a project as follows:
It can be seen from the above table that the installation of the hollow wall winding pipe saves more than 20% of the total cost of installing the reinforced concrete pipe, and the performance is much higher than that of the reinforced concrete pipe (especially the interface is good, avoiding leakage).


VII. Environmental safety measures

1 Use hot melt connection tools to pay attention to fire prevention to avoid fire.

2 The waste generated during construction should be concentrated and cleaned in time to prevent pollution.

3 Pay attention to personal protection during construction and avoid burns and burns.


Eight, quality requirements

1 The heating temperature and the required time and pressure should be in accordance with the regulations of the pipe and pipe fitting manufacturers.

2 The pipe and fittings are required to have the same melt index and the same manufacturer‘s product should be used.

3 Hot-melt pressure holding and cooling time shall comply with the regulations of pipe and pipe fitting manufacturers. During the cooling time, the connecting parts shall not be moved or external force shall be applied to the connecting parts.


Nine, engineering examples

In the Weihai International Commodity Exchange Center and other projects, this new type of pipe was used in combination with the specific conditions of the project and has been successfully installed and constructed. Because Weihai is located on the coast, the foundation of sandy soil, the foundation is easy to sink, choose

The pipe can successfully overcome the phenomenon that the drainage pipe joint is loose and the pipeline leakage occurs due to foundation settlement. And the excellent performance of the pipe also brings convenience to construction and management. Realized construction workers

The short period and high construction quality.


X. Conclusion

The successful application of hollow wall winding pipe in Weihai International Commodity Exchange Center and other projects shows that in the municipal sewage pipe network project, the hollow wall winding pipe is an ideal new pipe. With people on the quality of engineering

The increasing importance of quantity and the acceleration of the pace of plastic-removing steel in the pipeline industry, the hollow-walled winding tube has high strength, good water conservancy conditions, good sealing performance, convenient construction and installation, short engineering period and moderate construction cost.

Its characteristics will be widely promoted and used in the drainage pipe network project.

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