🔍 Key Concepts

• Function of a guarding valve in a boiler bottom blow system • Normal flow path of water/steam during a bottom blow and when valves are shut • What happens to idle vs. steaming boilers if a valve in the blow line leaks

💭 Think About

• Think about which component is closest to the boiler itself and which is closer to the ship’s shell or overboard discharge. Where is the guarding valve usually located? • If the main bottom blow valve starts leaking when the boiler is in service, what extra protection does the guarding valve provide? • Consider what risks exist both to a steaming boiler and to an idle boiler that shares the same blow line. Which one is the guarding valve primarily meant to protect?

✅ Before You Answer

• Be clear on the direction of possible leakage: from the boiler out, from the line back in, and from seawater inboard • Visualize a simple piping diagram: boiler → bottom blow valve(s) → guarding valve → ship’s side valve/overboard • Check which options describe distinct hazards and whether the guarding valve’s position could realistically prevent each one