🔍 Key Concepts

• Recognize valve symbols on piping diagrams, especially globe, gate, check, and stop-check valves • Understand that "downstream of point A" means following the direction of steam flow away from the boiler toward the soot blowers • Differentiate between valves used for isolation/flow control and those used for non‑return (check) or drain/gauge functions

💭 Think About

• Trace the line from point "A" toward the soot blowers and count how many distinct valve symbols appear, noting any that indicate non‑return (check) action • Compare the shapes of the valve bodies: which ones look like standard stop (shutoff) valves, and which (if any) have the hinged or spring symbol used for check valves? • Ask yourself whether this branch to soot blowers would logically need backflow protection, simple shutoff, or small connections for gauges/drains

✅ Before You Answer

• Confirm which symbol in the diagram represents a swing check valve versus a stop (globe or gate) valve from your valve‑symbol sheet or memory • Verify that downstream of "A" you are only including valves in the soot‑blower branch, not those connected to other services • Make sure the answer you choose matches both the symbol shapes you see and the most reasonable functional requirement of the soot‑blower supply line