Siphon Drainage Construction Plan
Comparison between the Siphon Roof Drainage System and Gravity Drainage System
1.1 The water in the siphon discharge system's pipeline is in full-tube flow, which can quickly and thoroughly drain the surface area. The gravity discharge system relies on gravity for force, with the water in the pipeline flowing along the walls, resulting in slow drainage speed and posing potential safety hazards to the building.
The horizontal pipe of the siphon discharge system does not require an incline, saving installation space; the gravity discharge system relies on gravity for flow, necessitating a certain incline in the horizontal pipe, which wastes installation space.
The siphon drainage system requires only a minimal number of rainheads and downspouts, thus saving on construction materials; in gravity drainage systems, the number of rainheads connected to a single downspout typically does not exceed two, necessitating a large quantity of rainheads and downspouts.
The piping for the 1.4 siphon discharge system is made of high-density polyethylene (HDPE) pipes, which are lightweight, shock-resistant, corrosion-resistant, and do not deform under heat, making them the optimal choice for rainwater discharge systems. The thermal expansion coefficient of the pipes is only 0.86%; in gravity discharge systems, the piping is typically PVC, which has drawbacks such as being non-abrasive, prone to scratching, poor welding, and high shrinkage rate. Although commonly used in general engineering projects, it has received numerous customer complaints.
The 1.5 Siphon Discharge System significantly reduces the pipe diameter of materials, easing construction challenges; whereas the Gravity Discharge System requires larger diameter pipe materials, making construction more difficult.
Construction Plan
The roof rainwater drainage system utilizes HDPE piping materials, welding techniques, and the siphon principle for its drainage system, which is at the international forefront in terms of material selection, installation processes, and system principles.
Construction Process
Construction Process Diagram
Pre-construction preparations
Measurement, Layout, Positioning
Pipe welding, pipe clamp fixation, on-site prefabrication, rainwater head installation
Pipe Filling Test
Completion of construction and acceptance inspection
2. Pre-construction preparation
2.1 The company is well-equipped with personnel and operation staff, establishing a dedicated project department for construction management.
2.2 Select high-quality workers with experience in installing siphon rainwater discharge systems for the project department and provide them with technical training by application engineers prior to their employment.
2.3 Thoroughly study engineering drawings, closely collaborate with designers and engineers, and meticulously consider construction plans.
2.4 Set up temporary facilities and arrange for the reasonable stacking of materials and machinery.
2.5 Arrange for the arrival of equipment, machinery, and auxiliary materials.
2.6 Enhanced supervision over construction personnel regarding engineering quality and the promotion of safe and civilized construction practices.
2.7 Welders and other工艺操作 personnel must hold valid certifications to perform duties.
2.8 Conduct on-site measurements strictly according to the construction drawings provided, and perform a re-inspection before the pipeline installation to ensure full compliance with the construction drawings and acceptance standards. (Note: If the pipeline mounting brackets are positioned on the steel structure, operations should be conducted according to the on-site positioning.)
Pipe Connections and Installation
The HDPE pipes for the siphon rainwater drainage system are connected using either焊接 (welding) or electrically welded pipe clamp fittings. The pipe welding is conducted strictly according to the pipe butt joint operation procedures, ensuring the quality of the pipe joints is straight and even, with the weld seams aligned in the same axial direction, with an axial difference error not exceeding 1 millimeter.
4. Welded Connection
4.1 Ensure cleanliness of the welding area and the tool plate during welding.
4.2 Adjust the welding plate temperature based on the weather conditions during construction
4.3 Apply correct and uniform force during the welding connection process.
4.4 The weld cross-section must be perpendicular at a 90° angle.
The following are the allowable thicknesses for the weld face—nearly half the thickness of the pipe.
|
Pipe diameter mm |
32-75 |
90 |
110 |
125 |
160 |
200 |
|
Surface weld mm |
3 |
4 |
5 |
5 |
7 |
7 |
Here is the direct reference for welding operation pressure:
|
Pipe diameter Fmm |
50 |
56 |
63 |
75 |
90 |
110 |
125 |
160 |
200 |
|
Pressure: Kg |
7 |
8 |
9 |
10 |
15 |
22 |
28 |
45 |
57 |
Here are the reference values for welding heating time and welding time:
|
Pipe wall thickness mm |
2 |
4 |
6 |
8 |
10 |
12 |
|
Heating Time m |
0.5 |
0.9 |
1.5 |
1.8 |
2.4 |
2.9 |
|
Welding Time m |
1.2 |
1.7 |
2.4 |
3.0 |
3.8 |
4.7 |
4.5 Welding Pipe Clamp Connector
Welding clamp connections are used for on-site welding, modification, supplementary installation, and repairs. This connection employs Shanghai Aikang's unique tool set—the welding kit. Before installation, both sides of the pipe must be sanded with sandpaper, then the welding clamp is fitted, power is connected, and the welding kit's red light illuminates. Press the yellow triangular button to initiate welding until the "V" button turns green, and the yellow label pops out, indicating the welding is complete.
5. Pipeline Fastening System Installation
The fixed pipe clips are installed with precision, ensuring a perfectly vertical alignment from top to bottom on the vertical plane of the pipeline. The position of the pipe clips forms a straight line on the horizontal plane.
5.1 Level Fixing Device
The project utilizes piping with diameters less than 250mm.
1) Please note the following rules regarding fixed points: Each Y-type fitting requires an anchor pipe clamp. On pipes with the maximum diameter, if the spacing between two Y-type fittings exceeds 5 meters, additional anchor pipe clamps must be added to ensure that the distance between adjacent anchor pipe clamps does not exceed 5 meters.
Siphon System Mounting Device
If the square steel is intermittent, two anchoring pipe clips need to be installed.
Every 2.5 meters, a connector is required to connect the roof to the wall.
4) Check that wedge fasteners have been inserted into each hoist and bracket.
The setting of guide tube clips refers to the table below.
If the distance between the rigid square steel guide rail and the ceiling exceeds 50 cm, we must implement measures to prevent horizontal displacement every 10 meters and at points where the direction changes.
5.2 Vertical Fixed System
Every 5 meters, there is an anchor pipe clip, and every 15 times the pipe diameter, there is a guide pipe clip. A fixed point is required before reaching the concrete road surface.
If the pipeline is exposed to direct sunlight, it must be installed according to the following method:
1) Solid Point:
Each Y-shaped tee requires one securing point. For larger pipe diameters, if the distance between two Y-shaped tees exceeds 3 meters, we must increase the securing points to ensure that no two securing points are more than 3 meters apart. There must be a securing point where the end rain tray and horizontal pipe (suspended pipe) connect to the vertical pipe.
2) Guide Tube Clamp
For pipe diameters over 125MM (including 125MM), a securing point is required every 0.8M. For diameters over 160MM, a securing point is needed every 1.2M.
6. Roof Rain Gutter Installation
Ensure proper connection methods and that the chosen rain leader matches the design. Rain leaders must be installed horizontally, and the pipes must be free of debris. Remove the cover plate to inspect the interior of the rain leader. If the rain leader was not factory-assembled complete, it is necessary to check that the internal piping lines and the gray connection lines of the rain leader align in a straight line. The quality of rain leader installation on the roof must achieve a seal, be level, and be firmly secured, with the rain leader surface at the same level as the roof eave gutter. The position of the rain leaders is evenly spaced in a straight line. The connection between the leak trap and the eave gutter, as well as the connection to the pipe, must be securely sealed and leak-proof.
This project includes both steel gutters and concrete gutters.
6.1 Concrete gutter installation with rainhead
The installation dimensions are as follows:
The waterproofing treatment for asphalt roof rain gutters requires close collaboration with a professional waterproofing manufacturer. The installation diagram is as follows:
6.2 Steel traffic canopy with rain collector
The installation dimensions are as follows:
During installation, an opening is made in the steel gutter according to the size of the rainwater installation sheet, followed by the use of TIG welding to attach the rainwater collector sheet to the gutter. This ensures the highest quality and appearance of the installation.
7. Overflow System Installation
This project implements overflow through the creation of overflow outlets in the gutters.
Overflow Port
8. System Filling Test
The pipeline installation is now complete, having been rigorously inspected to international and DIN standards, ensuring that every joint is leak-proof and watertight, with leak tests conducted.
9. Completion and Acceptance of the Project
Our company is coordinating with the general contractor for the final acceptance inspection of the project.
10. Construction Measures
On October 1st, a dedicated rainwater siphon system engineer will be responsible for converting design drawings into construction plans. They will also provide on-site construction guidance, address various operational issues, and supervise the workers' standard construction practices.
On October 2nd, the installation project of the roof rainwater pipeline in Exhibition Hall 10.2 was carried out with the aim of safety and quality assurance. The construction of a stable scaffolding was chosen, allowing workers to perform pipeline welding, pipe clip installation, and overall pipeline assembly operations on a solid working platform. This not only ensures the quality but also significantly enhances the safety coefficient of the project.
The construction of the scaffolding will be strictly implemented according to the construction specifications on October 3rd.
Construction Progress
In accordance with the overall construction progress requirements of the grand theater, we are specifically executing the engineering progress plan for the rainwater system. We are coordinating with subcontractors and the general contractor to ensure the timely completion of the construction task for the installation of roof rainwater drainage pipes.
Section 3: Quality Control
3.1 Our quality control system operates under a four-tier management structure:
(1) The Quality Supervision Department conducts inspections on the project department.
(2) Project Department for teams
(3) Between work teams (i.e., downstream processes for upstream processes).
(4) Team Self-Inspection.
3.2 Quality Assurance System
Installation and construction were strictly carried out in accordance with design requirements and construction specifications, with thorough technical handover, review of drawings, and technical confirmation. During construction, each process was subject to self-inspection by the work teams, and self-inspection records were meticulously maintained.
Ensure proper handover and acceptance between upstream and downstream processes. Construction of the next process can only be initiated after the upstream process is confirmed as qualified and signed off by the project quality officer.
Ensure thorough inspection of materials and finished products, guaranteeing that all pipe materials used during construction meet quality standards.
· Take meticulous records of construction activities, organize documents in accordance with technical file requirements, and assign a dedicated person to manage drawings and technical materials.
· Strictly enforce the quality punishment system for engineering projects, striving for top-quality projects
Section 4: Security Assurance
·Safety helmets must be worn on-site, and safety shoes and gloves must be worn during construction operations.
·Safety guidelines and penalty regulations are clearly written on warning signs and placed in prominent locations.
· Workers must wear safety belts when working at heights, and safety nets must be set up around the scaffolding.
·Construction workers are strictly adhering to the safety operation procedures, and professional engineering staff must hold certifications to work.
· Equipment operation requires dedicated personnel for maintenance to ensure optimal performance. Strictly prohibit damage to equipment caused by improper daily maintenance or inadequate operation.
·Exercise electrical safety precautions; strictly prohibit unqualified personnel from operating the power distribution system. The use of equipment in the power distribution system must comply with national regulations.
·Be vigilant about fire safety, especially at HDPE pipe material storage and welding sites. Strengthen fire awareness, ensure proper equipment allocation, and manage safety. Smoking is strictly prohibited at construction sites.
·In case of rush work and overtime night construction, ensure sufficient lighting brightness.
Civil Construction
Maintain an orderly construction process at the flag site and ensure the cleanliness of the construction site for surplus staff.
·Employees are prohibited from smoking and spitting at will; a penalty system is in place for unhygienic behavior.
Operators living on-site at the factory must comply with the arrangements and requirements of the construction site at the entire factory and the general contractor.
VI. Temporary Measures
Temporary measures on the construction site include a warehouse (for storing materials and equipment), an office (for the management and operation of the project department), and a rest room (for the rest of the construction workers), with the decision to reside, cook, and comply with unified regulations on the site being subject to specific provisions.
Be mindful of fire safety measures, particularly in warehouse storage areas, and increase the configuration of temporary facilities.
Enhanced management of temporary facilities, including material and equipment storage, personnel rest period management, and safety measures.
Section 7: Key Machinery and Personnel Equipment
1. Main Machinery:
· 1 Welding Machine
· 1 Pipe Cutting Machine
· Welding kit - 1 set
·And so on
2. Staffing
·Electrician 1 person
·Pipe Installer 5 Employees
·Assistant Personnel 1 Person
Note: Personnel allocation is tentative and will be adjusted according to the actual progress of the project.
