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Construction Plan for Water Supply, Drainage, and Heating Pipes 1. Preparation Notes This plan is applicable to the construction of water supply, drainage, and heating pipes for the 120,000-ton/year PVC resin project of XX Chemicals, part of XX Group. 2. Basis for preparation 2.1 \"Code for Acceptance of Construction Quality of Building Water Supply, Drainage and Heating Projects\" GB20242 2.2 \"Code for Construction and Acceptance of Welding Works of Field Equipment and Industrial Pipelines\" GB50236 2.3 \"Code for Construction and Acceptance of Industrial Metal Pipelines\" GB50235 3. Conditions required for construction 3.1 Complete set of construction drawings, installation specifications, standards and other relevant documents. 3.2 The delivered piping materials meet the construction requirements, and all the machinery, tools, instruments, and consumables necessary for construction are available in sufficient quantity. 3.3 The civil engineering works related to the pipelines have been inspected and found to meet the installation requirements, and the handover procedures have been completed. 3.4 Technicians, inspectors, and construction workers should thoroughly familiarize themselves with the drawings as well as relevant specifications, standards, and design requirements. Technicians should provide technical instructions to the personnel involved in the construction. 3.5 Inspect the pipeline components and pipe supports; those that pass the inspection shall be provided with a quality certificate. 4. Installation of water supply pipes 4.1 For the installation of pipes in various well chambers of the water supply system, if the design does not specify otherwise, when the pipe diameter is 450 mm or less, the distance between the well wall and the flange or socket must be at least 250 mm ； When the pipe diameter is greater than 450 mm, it shall not be less than 350 mm. 4.2 After the completion of the water supply pipes, they must be flushed. The drinking water pipes also need to be disinfected after flushing to meet the hygiene requirements for drinking water. 4.3 The paint on pipes and metal supports shall adhere well, without defects such as peeling, bubbling, running, or missed coating. 4.4 Pipe connections shall meet the process requirements, and valves and other components shall be installed in the correct positions. The pipe slope shall be constructed in accordance with the design requirements. 4.5 The pipeline network must undergo a hydrostatic test: the test pressure for water supplied within the plant is 1.0 MPa, while the test pressure for circulating water in the plant area is 0.4 MPa. Under this test pressure, the pressure drop should not exceed 0.05 MPa within 10 minutes; thereafter, the pressure is reduced to the operating level for inspection, and it should remain constant with no leaks. 4.6 The coordinates, location, and bottom elevation of the trench shall meet the design requirements. The bottom layer of the trench should be the original soil layer or compacted fill soil; the bottom of the trench must be level with a smooth slope, and there should be no sharp objects or boulders present. 4.7 For the backfilling of pipe trenches, sand or soil free of boulders and frozen soil clumps shall be used within 200 mm above the top of the pipes; mechanical backfilling is not permitted ； Within 500 mm above the top of the pipe, no rubble or frozen soil blocks with a diameter greater than 100 mm shall be used for backfilling; in the area beyond 500 mm, any such rubble or frozen soil blocks in the backfill shall not be concentrated. When mechanically backfilling the upper part, the machinery must not travel on the trench. 5. Installation of drainage pipes 5.1 The slope of the drainage pipes must meet the design requirements; it is strictly prohibited to have zero slope or a negative slope. 5.2 Before burying the pipes, a water filling test and a water flow test must be conducted; the drainage system must be unobstructed, with no blockages, and the pipe joints must be leak-free. 5.3 The coordinates and elevations of the pipes meet the design requirements. 5.4 The specifications, dimensions, and location of wells and ponds shall be correct, and the masonry and plastering shall meet the requirements. The manhole covers are properly selected and clearly marked, with elevations that meet the design requirements. 5.5 The drainage system shall be subjected to a filling test; there should be no leaks or seepages after 30 minutes, the water flow must be smooth, and it is considered qualified after a ball test. 6. Heating pipeline construction 6.1 The model, specifications, and nominal pressure of the balance valves and control valves shall meet the design requirements. After installation, carry out debugging according to the system requirements. And make a mark. 6.2 The preheating expansion of directly buried, uncompensated heating pipes and the reinforcement of tees shall meet the design requirements. Before backfilling, the integrity of the pre-fabricated insulation layer shell and its joints should be checked. Backfilling is carried out in accordance with the design requirements. 6.3 The position of the compensator must meet the design requirements, and it shall be pre-stretched in accordance with the design requirements or the product instructions. The location and design of the pipe fixing brackets must meet the design requirements. 6.4 The piping layout in the well room and at the user access points should facilitate operation and maintenance; the supports, hangers, and brackets must be secure and meet the design requirements. 6.5 The insulation of directly buried pipes meets the design requirements. When foaming is carried out at the joints on site, the thickness at those joints is consistent with that of the pipe’s insulation layer; moreover, the protective layer at the joints must be integrated with the pipe’s protective layer to meet the requirements for moisture and water resistance. 6.6 When pipes are laid horizontally, their slope shall meet the design requirements. 6.7 The structure of the dirt remover shall meet the design requirements, and its installation location and orientation shall be correct. The internal dirt should be removed after flushing the pipeline network. 6.8 The surface quality of the welds on pipes and pipe fittings shall comply with the following provisions: 6.8.1 The dimensional characteristics of the welds shall meet the requirements specified in the drawings and process documents; the weld height shall not be lower than that of the base material, and there shall be a smooth transition between the weld and the base material. 6.8.2 The surface of the weld and heat-affected zone shall be free from defects such as cracks, lack of fusion, incomplete penetration, slag inclusions, cratering, and pores. 6.8.3 The water supply or steam pipe of a heating pipeline, if not specified in the design, shall be laid on the right side or above the direction of flow of the heat carrier. 6.9 The hydrostatic test pressure for heating pipes shall be 1.0 MPa. Under the test pressure, the pressure drop should not exceed 0.02 MPa within 5 minutes; thereafter, it should be reduced to the operating pressure for inspection to ensure there is no leakage. 6.10 After the pipeline pressure test is successful, it should be flushed, and the test is considered successful if the water remains clear. 6.11 After the pipeline flushing is complete, water should be introduced and heating applied to carry out trial operation and debugging. When heating conditions are not available, it should be postponed. 7. Safety Precautions 7.1 Before entering the site, workers should be familiar with the safety and technical operating procedures. 7.2 When entering the site, wear the necessary protective equipment as required by different types of work. 7.3 Excavate the trench, slope it as specified according to the soil conditions; if the soil on the walls proves unstable, take reinforcement measures promptly. 7.4 When transporting materials using lifting equipment, it is strictly prohibited for anyone to be under the crane arm ； When inserting pipes into the trench manually, the rope-pressing method should be used; pipes must not be thrown into the trench, and no one should be present in the trench while pipes are being inserted. 7.5 Civilized construction practices should be observed at the construction site, with materials stored in designated areas as required.