Emergency relief systems include: which component is commonly used to vent overpressure?

• A. Pressure/vacuum vent valves
• B. Rupture disks
• C. Large-diameter piping
• D. Trained personnel

Answer: (A)

Emergency relief systems rely on devices that actively release gas or vapor when pressure climbs above safe levels. A pressure/vacuum vent valve is designed to open at a set pressure to vent excess gas, protecting the equipment and maintaining safe pressure, while also letting air in if a vacuum forms to prevent collapse. This reusability and dual function make it the standard choice for venting overpressure in relief systems. Rupture disks, by contrast, typically provide a one-time burst and require replacement after venting, so they’re not used as the regular venting component. Large-diameter piping is simply a conduit, and trained personnel, while essential for safety, is not a venting device.