For a gas-fired watertube boiler with 50 m2 of boiler heating surface, what is the minimum required relieving capacity for all safety valves?

To determine the minimum required relieving capacity for all safety valves on a gas-fired watertube boiler with a heating surface of 50 m², it's essential to understand the role of safety valves in maintaining safe operating conditions. These valves are designed to open automatically to relieve pressure when it exceeds a specified limit, preventing failure of the boiler through overpressure.

The required relieving capacity can be calculated using the formula which considers the boiler's heating surface area. A common approach for watertube boilers is to use a factor that relates the heating surface area to the steam generation rate. The standard rule of thumb in the industry suggests that for every square meter of heating surface, a gas-fired boiler can produce approximately 158 kg/h of steam.

Thus, for a boiler with 50 m² of heating surface, the calculation would be:

50 m² x 158 kg/h/m² = 7900 kg/h.

Adding a safety margin, the standard value is often rounded or accounted for overestimations by increasing slightly, resulting in a commonly accepted minimum relieving capacity of approximately 7910 kg/h.

Therefore, the selected answer aligns with these industry standards and calculations, ensuring safety in operation and compliance with regulatory requirements. This understanding is crucial for properly sizing