Pressure Relief Valves (PRVs) are critical safety devices designed to protect pipelines, vessels, and equipment from dangerous overpressure conditions. When system pressure exceeds safe limits, the valve automatically opens to release excess pressure, preventing equipment damage, process shutdowns, or catastrophic failures such as explosions or fire.

Across industries such as oil & gas, HVAC, power generation, and chemical processing, pressure relief valves must comply with strict engineering and regulatory standards including ASME Boiler & Pressure Vessel Code, API 520/521, and ISO 4126.  These standards form the foundation of best practices for selection, installation, and maintenance.

Best Practices for Selecting Pressure Relief Valves

1. Determine Accurate Set Pressure

Set pressure must match system design pressure and regulatory requirements. Choosing an incorrect set pressure can cause:

• Premature valve opening → process inefficiency

• Delayed opening → equipment risk

Industry standards typically require relief devices on pressurized equipment to ensure safe pressure control.

2. Consider Operating Conditions and Fluid Characteristics

Selection must reflect:

• Fluid type (steam, gas, liquid, corrosive media)

• Temperature range

• Back pressure conditions

• Flow rate and required discharge capacity

For example, pilot-operated PRVs may offer tighter sealing and higher operating-to-set pressure ratios but require cleaner media and more complex maintenance.

3. Ensure Compliance with Certification and Regulatory Requirements

Certified valves are tested for performance and capacity. In the U.S., pressure relief devices may carry National Board certification marks verifying compliance with recognized standards and testing procedures.

Best Practices for Operating Pressure Relief Valves

Routine Inspection and Testing

• Seat sealing integrity

• Spring or pilot mechanism accuracy

• No blockage in discharge lines

Periodic functional testing is recommended to confirm correct lift pressure and reseating performance.

Avoid Improper Installation

• Incorrect discharge piping sizing

• Installing valve in horizontal positions when not designed for it

• Excessive back pressure from long discharge piping