🔍 Key Concepts

• Purpose of a boiler safety valve – what is it designed to protect against? • How a safety valve reseats – does it close only when all pressure is gone, or at some safe margin below set pressure? • Difference between gradual opening and a rapid, “pop” action at set pressure

💭 Think About

• Think about what would happen to boiler operation if the valve stayed open until all pressure was gone – would that be practical or safe for plant operation? • Ask yourself whether you want the valve to creep open slowly or to open quickly once the set pressure is reached to relieve excess pressure effectively. • Consider how the valve should behave after opening: does it need to shut as soon as pressure dips slightly, or stay open until pressure has dropped by a certain safe amount?

✅ Before You Answer

• Verify which choice describes protection against overpressure while still allowing normal boiler operation afterwards. • Check which option mentions behavior relative to a set pressure and a pressure drop, not complete loss of pressure. • Eliminate any option that would clearly cause instability or damage to the boiler or valve, such as continuous chattering.