Electrical heating insulation construction plan

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I. Project Overview: This project involves high-speed electric heat tracing insulation work. The new pipelines that require electric heat tracing for insulation include: the pipelines in the valve chambers outside the tunnel, the pipelines from the tunnel entrances to the valve chambers, and the pipelines inside the pump house. II. Basis for preparation: 03S401 \"Insulation, dew prevention, and electric heating for pipes and equipment\", 03D705-1 \"Installation of electric heating and heat tracing equipment\". III. Process principle: The working principle of the electric heating system. The purpose of insulating pipes to prevent freezing is to compensate for the heat loss caused by the temperature difference between the inside and outside of the pipe casing. To achieve the purpose of preventing pipe freezing and maintaining insulation, it is sufficient to supply the heat lost by the pipeline, thereby preserving the thermal balance of the fluid inside the pipe and keeping its temperature almost constant. The heating cable pipeline insulation and anti-freezing system provides the heat lost by the pipeline to maintain its temperature relatively constant. The pipeline electric heat tracing insulation system consists of an electric heat tracing box, a power supply system for the heating cables, the heating cables themselves, and insulation materials. In operation, the temperature sensor is installed on the pipe being heated, allowing its temperature to be measured at any time. The thermostat compares the temperature set in advance with the temperature measured by the sensor, and uses the air switch in the heating cable control box along with overcurrent alarm functions to isolate the transmission, thereby cutting off or restoring power supply in a timely manner to achieve heating and anti-freezing effects. IV. Construction process flow: Pipe and valve installation → Wrapping heating cables → Fixing with heat-sensitive tape → Insulation → Commissioning. This pipeline anti-freezing electric heat tracing project mainly includes the electric heat tracing systems for pipelines outside the tunnel and those in the valve chambers. For each one-way tunnel, there is a valve well outside each tunnel opening; each valve well requires an electric heating box, one heating cable (180 meters long) and 50 meters of power supply cable, along with appropriate insulation material. Schematic diagram of the pipeline electric heat tracing anti-freezing system: file:///C:/Users/pc/AppData/Local/Temp/ksohtml6592/wps1.jpg When installing heating cables in pipe fittings, it is necessary to ensure the minimum bending radius of these cables; in principle, this minimum bending radius should be no less than 5 times their thickness ； When installing heating cables on pipeline valves, it is necessary to ensure ease of future inspection and maintenance. Installation of heating cables at pipe bends is shown in the image: file:///C:/Users/pc/AppData/Local/Temp/ksohtml6592/wps2.png. Installation of heating cables at pipe tees is shown in the image: file:///C:/Users/pc/AppData/Local/Temp/ksohtml6592/wps3.png. Installation of heating cables on valves is shown in the image: file:///C:/Users/pc/AppData/Local/Temp/ksohtml6592/wps4.png. When installing heating cables, there should be no kinks or tight bends; the outer coating of the cables must not be damaged during winding, and it is strictly prohibited to step on these cables. The number of locally wrapped heating cables should not be excessive, to prevent the pipes from overheating and damaging the heating cables; if wrapping is necessary, the thickness of the insulation should be reduced accordingly. After the entire system is installed, system debugging is required to ensure its proper and safe operation. Before insulation, first check that all pipes and fittings are properly installed, and that the heating cables are in good condition with no damage. Thereafter, the air circuit breakers for all circuits were turned off, each circuit was tested using a megohmmeter, and the results were recorded. Before powering on, it is necessary to check whether the power cable is connected, whether the heating cable is connected, and to verify that the electric heat tracing sensor is properly connected. Test to check whether the system is functioning properly, and also verify that all switches and indicator lights in the power supply box are working correctly. Conduct a power-on trial run, adjust the operating temperature of the electric heating element, lower or raise the operating temperature 3 times, and check whether the heating cable generates heat properly. Observe 3 heat tracing cycles and record the time for each cycle. V. Main tools and equipment: wire strippers, needle-nose pliers, wire spools, screwdrivers, electric knives, multimeters, megohmmeters, etc. VI. Quality Control: Standards such as \"03S401 Atlas for Insulation, Dew Prevention, and Electric Heating of Pipes and Equipment\", and the standard atlas \"03D705-1 for Installation of Electric Heating Systems and Heating Equipment\"; as well as the \"Code for Construction and Acceptance of Quality in Building Water Supply, Drainage, and Heating Projects\". VII. Safety Measures during Construction: 1. Safety education must be provided to construction workers before they start working on site. Adhere to the principle of \"safety first, prevention foremost.\" 2. Electrical work must be carried out by professional electricians; no one else is allowed to perform it. 3. When using mobile power tools, it is essential to have a leakage protector; the principle of \"one tool, one switch, one leakage protector\" should be followed, and the leakage protector must be sensitive and reliable. 4. Working on live electrical equipment is strictly prohibited; in case of special circumstances, an electrician must be present for supervision.