If a boiler in battery has a tube rupture, the automatic nonreturn valve will _______.

If a boiler in battery has a tube rupture, the automatic nonreturn valve will _______.

• A. Prevent steam flow from the steam header into the ruptured boiler
• B. Open to relieve pressure
• C. Shut off the fuel supply
• D. Isolate the feedwater line

Answer: (A)

In a boiler battery, the automatic nonreturn valve on the steam connection is there to prevent reverse flow of steam from the steam header back into a boiler that has ruptured. When a tube fails, the ruptured unit can experience pressure changes and hot steam from the header could be forced back into that boiler. The check valve automatically closes against this backflow, isolating the damaged boiler from the header and helping to protect the other boilers and the overall system. Relieving pressure by opening a valve is handled by separate safety devices, shutting off the fuel supply is controlled by interlocks for the burner, and isolating the feedwater line is done by feedwater valves—not by this steam-line nonreturn valve.

In a boiler battery, the automatic nonreturn valve on the steam connection is there to prevent reverse flow of steam from the steam header back into a boiler that has ruptured. When a tube fails, the ruptured unit can experience pressure changes and hot steam from the header could be forced back into that boiler. The check valve automatically closes against this backflow, isolating the damaged boiler from the header and helping to protect the other boilers and the overall system.

Relieving pressure by opening a valve is handled by separate safety devices, shutting off the fuel supply is controlled by interlocks for the burner, and isolating the feedwater line is done by feedwater valves—not by this steam-line nonreturn valve.