What are the key points for antifreeze checks?

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Freezing prevention inspections are an extremely important part of winter freezing prevention efforts. Conducting such inspections on a regular basis allows for the timely detection and resolution of issues that arise during the freezing prevention process, thereby effectively preventing further escalation of freezing-related problems. The anti-freezing inspection primarily aims to assess the effectiveness of anti-freezing and anti-condensation measures, identify any gaps, and further improve these measures. The main inspection items and methods are as follows: 1. Regularly inspect the drainage function of the steam tracing pipelines’ traps; if abnormal drainage is detected, it should be investigated and addressed promptly. In cases where it is not possible to directly observe the drainage situation (such as when it is directed to a drainage recovery station), a temperature gun or touch can be used to check the valve body of the drain valve (an inspection hole must be left available when insulation is in place). Generally, a temperature of over 30°C or a feeling of heat indicates normal operation; however, a warm sensation obtained through touch does not necessarily mean that the drainage is functioning properly, especially in situations where the drainage is sent to a recovery station, as heat conduction from nearby normal drainage pipelines can lead to misleading conclusions. 2. Use hot water for heating; use a flow indicator to check the flow of water, or employ a temperature gun or touch the designated inspection points on the electric heating tape to verify that the temperature of the electric heating tape is normal ； When the heat-traced hot water pipelines are collected together, experience should also be used to avoid interference from the heat conduction of the regular hot water pipelines, which could affect inspection and judgment. 3. For electric heating elements with temperature indicators, it is necessary not only to check the temperature readings regularly, but also to use a thermometer or touch the designated inspection points on the heating element to prevent inaccurate temperature readings and ensure that the temperature of the heating element remains within the normal range. Electric heating elements without temperature indicators still require temperature monitoring. 4. Enclosed workshops should be equipped with thermometers; the sealing of doors and windows as well as the temperature of the heating system should be checked regularly, and the heating level in the room should be adjusted according to the indoor temperature ； Inspect the insulation and sealing of the valve chamber, and monitor its internal temperature if necessary. 5. Regularly check whether there is any material flowing out or freezing and blockage at the low points of the emptied equipment and pipelines; alternatively, use a wrench to tap on the pipelines to assess the situation. If freezing and blockage is detected, identify the source of the material promptly and take appropriate action. 6. Regularly inspect the anti-freezing circulation systems of equipment and pipelines; if there are flow indicators or sight glasses, check whether the indications are normal ； In the absence of flow indicators or sight glasses, a temperature gun or by touching the device itself or the relevant anti-freezing wiring can be used to determine the temperature; when it is difficult to make such judgments based on temperature, a listening rod can also be used to assess the flow of material within the device or pipelines. For materials that use a small amount of external circulation for anti-freezing, regularly check whether the external discharge volume is normal. 7. Instrument heating: Regularly check the sealing condition of the instrument heating box as well as the temperature inside it. Also, in accordance with the heating method used, inspect the instrument heating following the aforementioned procedures ； Additionally, a comparison can be made using on-site and remote instruments, and the normal readings of these instruments can be used as a reference to determine whether the instrument is frozen or blocked. 8. Whether used on a long-term basis or as spare equipment, rotating the machinery regularly is necessary to detect in advance any signs of freezing or blockage ； For equipment that cannot be rotated (such as shielded pumps), in addition to ensuring proper anti-freezing circulation, a spot check should be carried out before starting; the temperature of areas prone to freezing (such as the back seat of the shielded pump) should be measured, and only after everything is normal should the equipment be started. 9. For drain valves at the ends of gas (vapor) pipelines, drain valves at the lowest points of U-turns, and valves at hose stations, maintain an appropriate degree of opening or conduct regular drainage checks to prevent material from accumulating in low-lying areas and causing pipeline blockages due to freezing. 10. For instrument air, in addition to regularly draining water from the ends of the main pipelines and at the lowest points, it is also necessary to check the dew point to prevent excessive moisture content from causing the instruments to freeze, which could lead to malfunctioning of the control systems. 11. Regularly check the outlets of the drainage facilities to ensure that water is not flowing out or that there is no freezing blockage at the low-point drainage valves. If any issues are detected, clear them promptly and verify that the valves at the source are properly closed. 12. Regularly inspect the system’s vent and breathing exhaust ports, such as the storage tank’s breathing valve and flame arrester, emergency vent ports for pressure relief, the air compressor’s vent port, and the boiler’s safety valve vent port, to ensure that these vents remain unobstructed. 13. Regularly check the protective nets and filters at the inlet of outdoor fans, as well as those at the inlets of the cooling fans of motors and other equipment, to ensure there is no freezing and blockage. Blockages are likely to occur if steam is released in the vicinity of such equipment or during snowy weather. 14. Regularly check whether the liquid in the outdoor water seal groove or liquid seal tank has frozen and caused blockages; address any abnormalities promptly to ensure its proper functioning. 15. In the event of a significant drop in temperature or at night, inspections should be intensified, and the amount of heat supplied, as well as the heating capacity of the factory buildings and the volume of fluid used in anti-freezing systems, should be adjusted according to the temperature conditions. A one-time solution is not sufficient to prevent freezing and blockages.