As the core component for water retaining and flood discharge functions in engineering projects, the quality of the shielded gate plate is directly related to the safe and stable operation of water conservancy projects. The key factors determining its quality include comprehensive elements such as steel selection, cutting, welding processes and equipment, and surface anti-corrosion treatment. To ensure the safe use of the shielded gate plate, this document elaborates in detail on the design, manufacturing, and technical requirements of the shielded gate plate from aspects such as material selection, performance standards, technical parameters, production processes, and quality assurance measures.

I. Performance Requirements

1. Specification Parameters: The specification of the shielded gate plate is 9960mm × 2900mm × 16mm. This size design is determined based on the actual needs of engineering water retaining and flood discharge, and can meet the application requirements of corresponding water conservancy project scenarios.
2. Material Standards: The gate plate is made of Q345D steel, which is selected through strict screening and meets the engineering requirements for the strength, toughness, and other aspects of the gate plate.
3. Anti-Corrosion Treatment: The anti-corrosion process adopts a multi-layer protection system consisting of hot-dip galvanizing, plus sealant and topcoat. Firstly, the surface of the shield plate is sandblasted to remove rust, reaching the Sa2.5 level standard; the thickness of hot-dip galvanizing should be greater than 120μm, the thickness of epoxy zinc-rich primer (zinc content ≥ 60%) should be ≥ 60μm, the thickness of epoxy micaceous iron intermediate paint should be ≥ 80μm, and the thickness of chlorinated rubber topcoat should be ≥ 80μm. All anti-corrosion links are strictly implemented in accordance with SL105-2007 Code for Anti-Corrosion of Hydraulic Metal Structures, with the requirement of adhesion ≥ 6MPa and the appearance color being silver gray.
4. Mechanical Performance Indicators: The yield strength is ≥ 335MPa, the tensile strength is between 450-630MPa, the elongation is ≥ 17%, and the impact absorption energy is ≥ 34. These indicators ensure that the gate plate can withstand corresponding loads and impacts under various working conditions.
5. Service Life: The designed service life of the shielded gate plate is 30 years, which is determined by comprehensively considering factors such as material performance, anti-corrosion effect, and actual engineering needs.

II. Shield Structure and Material Selection

1. Composition of Shielded Gate Plate
   • The gate leaf is made of Q345D material, ensuring the overall strength and stability of the gate plate.
   • The basic flexible connection in the basic hinge device adopts EPDM high-strength anti-detachment rubber flexible connection, and the basic flexible connection pressing plate is Q345D steel plate, ensuring the flexibility and connection strength of the hinge device.
   • In the water stop system, the side water stop adopts L-type rubber water seal, the water stop between shield plates adopts anti-detachment rubber water seal, and the water stop fasteners are stainless steel bolts, which effectively ensure the water stop effect of the gate plate and prevent leakage.
2. Material Selection Standards
   • All materials purchased for this project must strictly comply with the specifications of the design drawings in terms of type, specification, and total quantity. The mechanical properties and chemical composition of the materials must meet the standards issued by the People's Republic of China, and the factory qualification certificate must be presented to the purchaser before installation.
   • The gate leaf material is Q345D, supplied by Baosteel Group Co., Ltd., ensuring material quality from the source. The performance of this material complies with the requirements of GB/T1591-2008 standard, with good comprehensive mechanical properties, excellent low-temperature performance, and good plasticity and weldability, which can adapt to the complex environment of water conservancy projects.
   • The welding material is E43 type electrode, whose performance complies with the relevant regulations of GB5117, GB5118, GB981, GB984, or GB983, and must have a product quality certificate. The storage and 保管 of electrodes shall comply with the provisions of standard JB3223 to ensure stable and reliable welding quality.

III. Quality Assurance Measures

1. Strictly select high-quality materials, and ensure the first-class quality of the shielded gate plate based on high-quality materials.
2. Strengthen the material incoming inspection link to ensure that the material performance meets the requirements of the construction drawings, and its mechanical properties and chemical composition comply with current national standards and industry standards, and have a factory qualification certificate; materials without a factory qualification certificate, unclear labels, incomplete data, or with questionable data shall not be used, and can only be put into use after passing the inspection; at the same time, if the surface defects of the steel plate exceed the provisions in GB3274-82, they shall not be used for this product.
3. Properly store and use the incoming materials, stack the materials in reasonable categories, place them stably to prevent deformation and damage; label them with type, specification, and batch number for easy management and traceability; store the materials in a dry and ventilated warehouse, pay attention to preventing rust and pollution, and ensure that the materials are in good condition before use.