Two Common Problems of Pressure Vessels in Air Compressor Systems – Does Your Facility Have These Risks?

As an important source of energy, air compressors are widely adopted in various production and daily scenarios. Many electronic manufacturing enterprises in Wujiang extensively utilize compressed air on production lines.
Most air compressor systems in enterprises are equipped with oil separators and air receivers. Both items belong to pressure vessels, which require registration for usage and periodic inspection.
Pressure vessels are special equipment with high inherent hazards. The original operating conditions of such equipment shall not be altered arbitrarily. Please check whether your enterprise has the following two common violations:
1. Random sealing of flange connections with blind plates during pipeline modification

Standard blind flanges shall be used for pressure vessel flanges, as they are designed with adequate strength, rigidity and other performance requirements. However, 

operators often neglect this requirement and seal flange openings randomly, which inevitably creates potential safety hazards.

Case Example

Recently, inspectors from the Pressure Equipment Division of Wujiang Branch conducted an inspection at a user site. They found that non-standard blind plates were used to seal the pipe flanges of pressure vessels, 

and fastening bolts were not fully installed, which seriously violated design specifications. The inspectors immediately issued rectification requirements for the enterprise, eliminating a potential accident risk.

2. Misconception: Equipment can run without safety valves due to safety interlock protection devices

As overpressure relief devices, safety valves play a vital role in the safe operation of pressure vessels. When the vessel exceeds the design pressure, 

interlock devices cannot directly and rapidly discharge internal pressure, which may lead to vessel rupture and explosion caused by overpressure. 

Therefore, safety interlock protection devices cannot replace pressure relief devices for pressure vessels.

Case Example

During a recent inspection of pressure vessels at one enterprise, our inspectors discovered that the air receiver was not fitted with safety valves as specified in technical documents. 

The original valve connection port was directly sealed with a pipe plug. Operation under overpressure conditions would pose severe risks.

Friendly Reminder

If the pressure vessel can only be shut down temporarily due to production demands, the user may prepare a spare safety valve of identical model and specification. 

Carry out calibration first, then replace the valve to minimize downtime.