The maximum size bottom blowdown valve on a boiler is what dimension?

The maximum size bottom blowdown valve on a boiler is defined by various codes and standards that govern boiler operation and safety. A bottom blowdown valve is crucial for removing sludge and sediments that accumulate at the bottom of a boiler.

The dimension of 2 1/2 inches is significant because it strikes a balance between effective drainage of the accumulated materials and safety considerations. A blowdown valve larger than this could potentially lead to excessive water release, which might not only cause a rapid loss of water and potentially lead to operational problems but also create hazards due to steam and hot water discharge. Therefore, the specification of a maximum size ensures proper control of the blowdown process while adhering to best practices in steam system safety and efficiency.

In contrast, the other options reflect either smaller sizes that may not adequately handle sediment removal in larger systems or conflicts with safety standards and practical operational limits.