Question 57

Shut-off valves on both supply and return are the most suitable placement for periodic internal boiler inspections.

Having shut-off valves on both the supply and return lines allows for complete isolation of the boiler during inspections. This setup is essential for ensuring safety and efficiency while maintaining the system.

A) Shut-off valve on supply only

While a shut-off valve on the supply only can isolate the incoming water, it does not allow for the complete draining or isolation of the boiler system. Without a valve on the return line, it would be difficult to control the pressure and flow, which is crucial during an inspection.

B) Shut-off valve on return only

A shut-off valve on the return line can prevent water from exiting the boiler but does not address the supply side. This placement would not allow for adequate isolation of the boiler for an inspection, as water could still enter from the supply side.

C) Shut-off valves on both supply and return

This option is the most appropriate for periodic internal boiler inspections. Having valves on both lines enables the operator to completely isolate the boiler from the system, allowing for safe maintenance and inspection without risking water flow or pressure issues.

D) No shut-off valves. Drain entire system

Not installing any shut-off valves and opting to drain the entire system is not practical. This method can lead to unnecessary downtime and potential complications in refilling and pressurizing the system post-inspection, making it less efficient than having shut-off valves.

Conclusion

The ideal configuration for preparing a boiler for inspection is to have shut-off valves on both the supply and return lines, as this ensures complete isolation and safety during the process. The other options either fail to provide adequate isolation or introduce inefficiencies that could complicate routine maintenance. Thus, option C is definitively the best choice.