Valve "H" shown in the illustration,...

🔍 Key Concepts

• Study the fuel oil flow path from the pumps through the heaters and to the boiler fronts, paying close attention to where valve H is located in relation to the burners and return lines. • Compare the symbol used for valve H with other valves on the diagram (is it a simple stop valve, a check valve, or a remotely operated/quick-closing type?). • Think about normal fuel control: which components actually regulate fuel flow to the burners versus which components provide safety isolation or recirculation paths.

💭 Think About

• If fuel oil is flowing normally to the boiler burners, what happens if valve H is shut? Where does the fuel flow stop? • Does any piping from valve H lead back to the settling/service tanks, or does it only serve as a barrier between the main fuel header and the boiler fuel manifolds? • In an emergency such as a furnace fire, which type of valve function would be most important to have at the boiler front: flow regulation, recirculation, or rapid isolation?

✅ Before You Answer

• Verify whether any line from valve H goes back to the fuel tanks (this would suggest recirculation). • Verify whether valve H is drawn as a check valve symbol (for backflow prevention) or as a shutoff/operated valve on the supply line. • Confirm where the actual fuel metering/control valves to the burners are located, and whether they appear separate from valve H.

Valve "H" shown in the illustration, functions to __________. Illustration SG-0009

regulate the amount of fuel burned

recirculate fuel oil during start-up

provide a quick shut off of fuel to the boiler

prevent a backflow from the manifold

🔍 Key Concepts

💭 Think About

✅ Before You Answer