What is the primary purpose of a Pressure Relief Valve?

• A. To maintain a constant pressure in the boiler
• B. To prevent overpressure in the system
• C. To measure steam output
• D. To regulate feedwater flow

Answer: (B)

The primary purpose of a Pressure Relief Valve is to prevent overpressure in the system. This component is a critical safety device designed to automatically release excess pressure from a vessel or piping system when it exceeds a predetermined limit. By doing so, it helps protect the boiler and associated components from potential damage or catastrophic failure due to excessive pressure buildup.

When the pressure within the system rises to an unsafe level, the pressure relief valve opens, allowing fluid (often steam or water) to escape. This action reduces the pressure back to a safer range, thereby preventing explosions and ensuring the safe operation of the boiler system.

Other options, such as maintaining a constant pressure, measuring steam output, or regulating feedwater flow, are functions typically associated with other devices, such as pressure control valves, flow meters, or water level controls. These devices serve their specific purposes but do not address the critical safety function that pressure relief valves provide in preventing overpressure conditions.