Guidelines for Safety Valve Selection and Installation in Pressure Vessels
On this page
When it comes to pressure vessels in industrial production, safety valves play a crucial role. Pressure vessels not only withstand critical pressures and risks but also directly impact the stability of production processes and personnel safety. In this context, safety valves serve as pivotal devices ensuring the safe operation of pressure vessels, making their correct selection and precise installation paramount.
Regular Inspection and Pressure Setting
Before installation, safety valves should undergo periodic inspections by experienced professionals to ensure their performance meets requirements, with inspections ideally conducted at least annually. The set pressure of safety valves typically ranges from 1.05 to 1.10 times the maximum working pressure of the pressure vessel, not exceeding the design pressure (excluding transportable pressure vessels).
Correct Installation of Safety Valves
The installation position of safety valves directly affects their effectiveness in providing safety protection. Specific installation requirements include:
1. Vertical Installation
Safety valves should be installed vertically to ensure proper operation and timely response to pressure anomalies.
2. Vapor Space Installation
They should be installed in the vapor space above the liquid level of the pressure vessel or directly connected to vapor space piping.
3. Connection and Orifice Requirements
The cross-sectional area of connecting pipes and fittings should not be smaller than the inlet area of the safety valve to ensure proper pressure relief.
4. Multiple Valve Installation
When multiple safety valves are installed at one connection, the inlet area should be at least equal to the sum of all safety valve inlet areas to ensure effective pressure relief.
5. Use of Stop Valves
It is not recommended to install intermediate stop valves between the pressure vessel and safety valves. However, for specific conditions (e.g., flammable medium vessels), stop valves should be installed between the safety valve and the vessel for ease of safety valve replacement and cleaning.
Special Requirements for Closed Safety Valves
Special requirements for closed safety valves typically revolve around ensuring safe discharge of gases and preventing hazards related to discharge and maintenance. Here are some key considerations.
1. Discharge Pipe Arrangement
They must be equipped with discharge pipes to safely release gases outdoors or to other designated safe areas. The effective diameter of the discharge pipe should not be less than the outlet diameter of the safety valve and should be reliably supported to prevent vibration or additional stress on the vessel when the safety valve opens.
2. Electrostatic Grounding
Conductive grounding is necessary for discharge pipes handling flammable media to prevent static buildup and associated safety hazards.
3. Drain Pipe Arrangement
If discharge pipes may accumulate condensate or rainwater, drain pipes should be installed at the lowest point to ensure timely liquid discharge and prevent backpressure affecting the safety valve's discharge effectiveness.
Convenience of Inspection and Maintenance
The installation position of safety valves should facilitate regular inspections and necessary maintenance to ensure they remain in optimal working condition. This includes checking the sealing, pressure relief performance, and the clear passage of discharge pipes.
Response Measures After Safety Valve Operation
Following safety valve activation, it is crucial to promptly identify the cause of increased vessel pressure and take effective measures to prevent further escalation, thereby avoiding disruptions to equipment operation and ensuring personnel safety.
In summary, the selection and installation of safety valves involve various technical requirements and operational details that must strictly adhere to relevant standards and regulations. Proper management of these aspects not only ensures equipment safety and long-term stable operation but also directly impacts the safe operation of pressure vessels and personnel health. In practical applications, prioritizing the functionality and quality of safety valve installation is essential to maintain their optimal performance at all times.
