What are some common operational errors involving pressure vessels?

I. Personnel Operation Violations (Primarily Human Factors)

1. Unlicensed Operation or Lack of Professional Training: Operators without a valid "Special Equipment Operator Certificate" and lack basic knowledge of equipment structure, process parameters, and emergency response procedures pose a significant safety hazard.

2. Operation Under Pressure or Improper Tightening: Unauthorized disassembly of flange bolts or maintenance work while the vessel is under pressure can easily lead to a sudden release of high-pressure media, causing physical injury.

3. Operation Over-Temperature/Over-Pressure, Blindly Pursuing Output: Intentionally disabling safety interlock devices or operating equipment beyond limits to increase efficiency can easily lead to explosions if safety valves fail.

4. Failure to Properly Handle Hot Work: Welding without hot work analysis, blind flange isolation systems, or a hot work permit during maintenance may ignite residual flammable gases, leading to an explosion.

5. Valve misoperation or incorrect opening/closing sequence: Incorrect valve operation or delayed valve closure can lead to gas backflow, equipment overpressure, or uncontrolled reactions, causing physical or chemical overpressure.

II. Equipment Management and Maintenance Errors

1. Failed or uncalibrated safety accessories: Failure to calibrate safety valves and pressure gauges on schedule (safety valves annually, pressure gauges semi-annually) prevents timely release or alarm response in case of overpressure.

2. Arbitrary sealing of flange interfaces with blind flanges: Using non-standard blind flanges to seal pipe openings, with incomplete bolt assembly and insufficient strength, poses a serious risk of leakage or bursting.

3. Failure to install safety valves or sealing them off: Misconception that "interlock protection eliminates the need for safety valves," but interlocks cannot replace pressure relief. Once overpressure occurs, there is nowhere to release pressure, which is extremely dangerous.

4. Operating equipment with defects: Continuing to use equipment knowing that safety interlock devices are malfunctioning, such as forcibly starting an autoclave when protection fails, has resulted in multiple injuries and fatalities.

III. Errors in Process Handling and Emergency Response

1. Incomplete Replacement Before Trial Run or Maintenance: Failure to effectively replace the container or incorrect replacement sequence allows residual flammable gas to mix with air, creating an explosive environment that will explode upon ignition.

2. Feeding Too Quickly or Using the Wrong Material: Feeding too quickly causes a sharp increase in temperature; feeding the wrong material may lead to uncontrolled chemical reactions, generating large amounts of gas and causing overpressure.

3. Improper Emergency Response: Failure to promptly shut down the machine, cut off the source, or organize evacuation when leaks or overpressure occur; instead, blindly attempting rescue, exacerbating the consequences of the accident.

4. Neglecting Daily Inspections and Records: Failure to adhere to the daily inspection system results in the failure to promptly detect leaks, vibrations, corrosion, and other problems, missing the window of opportunity for hazard mitigation.