Identify the device described as opening during emergencies to prevent a rise in internal pressure.

• A. Pressure relief device
• B. Preservice test
• C. Relay Pumping
• D. Slow operating valve

Answer: (A)

A pressure relief device is designed to open automatically when the internal pressure exceeds a set limit, venting fluid or gas to prevent overpressure. This keeps the system safe from rupturing or sustaining damage. It’s typically spring-loaded (or otherwise biased) so that once the pressure reaches the crack point it opens, and it closes again once pressure drops to safe levels.

Preservice test isn’t a device but a pre-service check of equipment. Relay pumping is a method for supplying water using multiple pumps. A slow operating valve is meant to dampen pressure surges by opening gradually, not primarily to prevent sustained overpressure.