What are some common operational mistakes when operating pressure vessels?

I. Mistakes in Personnel Qualification and Training

1. Unlicensed Operation or Incompatible Certificates: Operators may operate equipment without a valid special equipment operator certificate (e.g., R1, R2 certificate), or the certificate category may not match the actual equipment being operated. According to the "Special Equipment Safety Supervision Regulations," this is illegal and will result in fines or even criminal charges.

2. Lack of Regular Training and Emergency Drills: Even with a certificate, failure to complete 8 hours of emergency training (including VR simulated accident handling) every two years as required will make it difficult to cope with emergencies and increase the risk of accidents.

II. Typical Errors During Operation

1. Failure to Conduct Pre-Commissioning Safety Inspections: Failure to check the completeness and effectiveness of safety accessories such as safety valves, pressure gauges, and thermometers before commissioning, or continuing to "use first and deal with later" even when the following problems are found:

Safety accessories lack product qualification certificates; No nameplates prevent parameter identification; Overdue calibration; Specifications or performance do not meet requirements.

The above conditions must not be met for use, otherwise, an explosion may occur due to safety device failure.

2. Rapid Pressure/Heating Rates: Rapid loading (pressure/heating) and unloading (pressure/heating) processes can cause excessive thermal or mechanical stress on the container, easily leading to fatigue cracks or structural deformation.

3. Frequent or Significant Pressure/Temperature Fluctuations: Frequent fluctuations in pressure and temperature can induce alternating stress, accelerating material fatigue damage, especially in high-stress areas such as pipes, welds, and openings.

4. Pressurized Tightening or Repair: Tightening bolts or disassembling parts while the container is still under pressure can easily lead to sudden leaks or flying parts causing injury.

5. Incorrect Valve Operation or Switching Sequence: This can cause backflow of the medium, overpressure, or open-pressure operation, potentially leading to physical explosions or uncontrolled chemical reactions.

III. Maintenance and Management Oversights

Overpressure, Overtemperature, and Overload Operation: Blindly increasing operating parameters in pursuit of higher output, exceeding design limits, seriously threatens the structural integrity of the equipment.

1. Neglecting Replacement and Hot Work Management

Failure to thoroughly replace the internal medium before equipment maintenance can lead to the formation of an explosive mixture. Welding operations performed without a hot work permit or blind flange isolation can easily cause a fire or explosion.

2. Using Combustible Gas for Pressure Testing and Leak Detection
Using oxygen or combustible gas to pressurize the system for leak detection in violation of regulations can lead to an explosion upon contact with an ignition source.

3. Feeding Materials Too Quickly or Using Incorrect Materials
Feeding materials too quickly can cause a rapid increase in temperature, or incorrect material feeding can lead to uncontrolled reaction, decomposition, and explosion.

IV. Improper Management of Safety Accessories

1. Safety valves have not been calibrated for a long time or have been disassembled without authorization.

2. Pressure gauges have insufficient accuracy or have exceeded their calibration period.

3. Rupture discs have not been replaced regularly and have lost their protective function.

4. Insufficient quantity or type of protective devices, especially in flammable and explosive environments.