Thread Content
Safe operation of pressure vessels: Proper and rational operation of pressure vessels is an important measure to ensure their safe operation. Even if a vessel is designed in full compliance with requirements and manufactured and installed to high standards, improper operation can still lead to accidents involving that pressure vessel. As a key piece of equipment in the petrochemical production process, pressure vessels must be operated safely by ensuring the following: 1. Steady operation – Frequent changes and large fluctuations in pressure during operation are detrimental to the vessel’s resistance to fatigue damage. The operating pressure should be kept stable as much as possible. At the same time, during operation, the container should also avoid sudden changes in shell temperature to prevent excessive thermal stress. When loading (increasing pressure or temperature) and unloading (decreasing pressure or temperature) a pressure vessel, the process should not be carried out too quickly, in order to prevent rapid changes in pressure or temperature from having adverse effects on the vessel. II. Preventing Overloading Preventing overloading of pressure vessels mainly involves preventing excessive pressure. In reaction vessels, the feed rate and reaction temperature must be strictly controlled to prevent the reaction from getting out of control and causing overpressure in the vessel. When filling storage vessels with feed, precise measurement is essential to avoid overfilling, thereby preventing the material’s thermal expansion from leading to overpressure in the vessel. III. Status Monitoring Pressure vessel operators must continuously monitor the operating condition of the vessel during its operation, detect any abnormalities that may arise, and take appropriate measures to ensure safe operation. The supervision and control of the container’s operating status are primarily carried out in terms of process conditions, equipment status, safety devices, etc. (1) Process conditions Check whether the operating pressure, temperature, liquid level, etc. are within the ranges specified in the operating procedures ； Whether the chemical composition of the working medium inside the container meets the requirements, etc. (II) Equipment condition The main focus is on checking whether there are any deformations, cracks, leaks, corrosion, or other defects or suspicious signs in the container itself and in the parts that are directly connected to it, such as manholes, valves, flanges, and the connections for pressure, temperature, and level instruments ； Check whether there is vibration or wear on the containers, pipelines connected to them, and other related equipment ； Whether the equipment’s insulation (cooling) is in good condition, etc. (III) Safety devices Mainly check the condition of various safety accessories and measuring instruments, such as whether any of the instruments are inaccurate or clogged ； Whether interlocks and alarms are operating reliably, whether they are within their allowable service life, and whether outdoor equipment freezes in winter, etc. IV. Emergency Shutdown When a pressure vessel exhibits any one of the following abnormal conditions, the operator must immediately take emergency measures and report to the relevant departments within the organization in accordance with the prescribed procedures. These phenomena mainly include: (1) work pressure, sudden changes in the medium, medium temperature or wall temperature exceeding allowable values, and the situation not being effectively controlled despite taking measures ； (2) Safety-threatening defects such as cracks, bulging, deformation, and leakage in the main stressed components ； (3) Failure of safety accessories ； (4) Damage to the fittings and fasteners, making it difficult to ensure safe operation ； (5) A fire occurs, directly threatening the safe operation of the pressure vessel ； (6) Overfilling ； (7) Liquid level out of control ； (8) Severe vibration in pressure vessels and pipelines, posing a threat to safe operation, etc.