In industrial production, pressure vessel play an indispensable role. They are widely used in chemical, petroleum, pharmaceutical, food processing, and other industries. However, the operation of pressure vessel is accompanied by potential risks. Improper operation may lead to serious safety accidents, resulting in casualties and property losses. Therefore, ensuring the safe operation of pressure vessel is a fundamental principle that every operator must strictly follow. This article provides a detailed overview of the operating standards, safety measures, and emergency handling methods for pressure vessel to help operators better understand and master key operational points, ensuring production safety.
Pressure vessel operation is a highly specialized task. Operators must undergo professional training and obtain the appropriate operation certificate before performing independent operations. This requirement not only ensures the operator’s personal safety but also guarantees the overall safety of the production process. Before starting work, operators should be familiar with the equipment and pressure vessel’s technical characteristics, structure, process flow, and process parameters. They must also understand potential accidents, preventive measures, and emergency handling methods. Only with this foundational knowledge can operators remain confident and prepared during actual operation to handle various situations effectively.
Before starting the equipment, operators must conduct a thorough inspection to ensure the system is in proper working condition. The inspection includes checking for visible abnormalities such as deformation or cracks, verifying that safety accessories and devices meet requirements and are complete, sensitive, and reliable, checking pipeline joints and valves for leaks, and confirming that operation parameters, process indicators, and the specified maximum and minimum working pressures and temperatures are clear. Equipment should only be started after confirming that all safety conditions are met.
The start-up and shutdown of pressure vessel and related equipment must strictly follow the safety operating procedures for the position. During these operations, pressure must be increased or decreased gradually in stages to avoid sudden temperature or pressure changes that may damage the equipment. Operators must strictly control process conditions and closely monitor instruments, devices, and accessories to prevent over-temperature or over-pressure operation. For special pressure vessel, such as those requiring specific wall temperatures during pressurization, pressurization must not begin before the wall temperature reaches the specified value. For liquefied gas vessel, during each refilling from an empty state, operators must strictly control the filling speed to prevent excessively low wall temperatures that can cause brittle failure, and also control filling volume to prevent overfilling or explosion accidents.
Safety measures are of utmost importance during pressure vessel operation. For pressure vessel containing flammable, explosive, or toxic media, operators must take special care to prevent leaks or incorrect charging, ensure good ventilation, and maintain effective fire prevention measures. For reaction pressure vessel with linings or refractory materials, wall temperature should be regularly checked during operation or nitrogen purging; if abnormalities are suspected, reinspection should be performed. Each time materials are added for a reaction, the quantity must be accurately weighed, and the material specifications must comply with process requirements.
Routine patrol inspections should be conducted at fixed times, fixed points, and along fixed routes to ensure stable operation. Additionally, safety valves, pressure gauges, temperature measuring instruments, emergency shut-off devices, and other safety equipment must remain complete, sensitive, and reliable. Each shift should inspect and test them according to regulations. Details of patrols, inspections, and adjustments should be recorded in duty logs and equipment defect records for future management and maintenance.
During operation, if any of the following occurs, the operator has the right to take emergency measures to stop the pressure vessel and must immediately report to relevant supervisors and departments:
The pressure vessel’s working pressure, temperature, or wall temperature exceeds allowable limits and cannot be restored by corrective measures.
Major pressure-bearing components develop cracks, bulging, deformation, or leaks that cannot wait for the next maintenance cycle.
Safety devices or main accessories fail, or connections and fasteners are damaged, making safe operation impossible.
Fire or other accidents directly threaten the pressure vessel’s safe operation.
After an emergency shutdown, restarting the pressure vessel must be approved by the responsible leader and chief engineer. Restarting is strictly prohibited before identifying the cause and implementing corrective measures. During operation or pressure testing, it is strictly forbidden to repair, tighten, dismantle, or weld any pressure-bearing components. For operations such as thermal tightening or adjustments allowed by procedures, operators must strictly adhere to safety specifications. When checking or testing under pressure, personnel should keep their heads away from potential hazard zones and follow predetermined inspection routes.
When entering the interior of a pressure vessel for operation or inspection, the following safety precautions must be taken:
Cut off the pressure source and isolate all connected equipment and pipelines with blind plates, clearly marking the isolation points. Valves alone must not be used as isolation.
After disconnecting the power supply, lock the distribution box or cabinet and hang warning signs.
For pressure vessel containing flammable, toxic, highly toxic, or asphyxiating media, operators must perform purging, neutralization, disinfection, and cleaning, followed by sampling and analysis to confirm safety compliance.
Open all manholes and handholes for ventilation and ensure sufficient air circulation.
For idle or standby pressure vessel, maintenance and inspection should be conducted according to regulations. If necessary, the pressure vessel should be emptied, cleaned, and purged to ensure it remains in good standby condition.
Pressure vessel operators bear great responsibility. They must strictly follow operation procedures, correctly use pressure vessel, and ensure safe operation. Operators must also perform maintenance to keep pressure vessel in good technical condition, regularly inspect operation status, make timely adjustments when abnormal conditions occur, and take emergency measures when necessary, promptly reporting to their superiors.
Inspection during operation is an important aspect of dynamic monitoring for pressure vessel. Its purpose is to detect abnormal conditions in operation or equipment in time and take corrective actions to prevent escalation and ensure safe operation. For pressure vessel in operation, three key aspects should be checked:
Check whether operating pressure, temperature, and liquid level are within the specified safe range. Verify that the working medium’s chemical composition, material ratio, and feeding quantity meet requirements, especially components affecting pressure vessel safety.
Inspect pressure vessel connections for leaks or seepage; check components and attachments for deformation, corrosion, or other defects; and observe for vibration or wear in the pressure vessel or connected pipelines.
Check safety devices and related instruments, such as thermometers and weighing instruments for feeding or liquefied gas filling, to ensure proper function. Verify that pressure gauge impulse lines are not leaking or blocked, that spring-type safety valve springs are free from rust or oil adhesion, and that outdoor safety valves show no signs of freezing in winter. Ensure all instruments are within their service period.
Patrol inspections during operation should be conducted at fixed times, points, and routes. Operators should carry inspection tools and carefully follow the established route and checkpoints.
During operation, if any of the following abnormalities occur, the operator must take emergency measures immediately and report to relevant departments according to procedures:
Working pressure, medium temperature, or wall temperature exceeds allowable limits and cannot be controlled.
Main pressure-bearing components develop cracks, bulging, deformation, or leaks threatening safety.
Safety accessories fail.
Connections or fasteners are damaged, compromising safety.
Fire directly threatens pressure vessel safety.
Overfilling occurs.
The liquid level becomes uncontrollable and remains so after corrective measures.
Severe vibration occurs between the pressure vessel and pipelines, endangering safety.
In emergencies, operators must quickly cut off power, stop all feeding equipment such as pumps and compressors, contact relevant posts to halt material transfer, open outlet valves to release gas or material from the pressure vessel, and, if necessary, open vent valves to discharge gas into the atmosphere. For continuous process systems, operators must coordinate emergency shutdowns with upstream and downstream posts. Operators should also immediately contact their supervisors and technical personnel to effectively control the situation and prevent major accidents.
Safe operation of pressure vessel is a critical aspect of industrial production that must not be overlooked. Operators must strictly follow procedures, hold valid certificates, understand equipment characteristics, and perform proper pre-start inspections, start-up and shutdown operations, safety precautions, emergency handling, internal entry measures, operational checks, and abnormal condition management. Only through these measures can pressure vessel operate safely, production run smoothly, and the lives and property of personnel be protected. It is hoped that this guide helps operators better understand and master knowledge of pressure vessel operation, enhance safety awareness, and standardize operational behavior to contribute to the stable and safe development of industrial production.
