In a gas-fired watertube boiler with 70 m2 of boiler surface and one safety valve on the superheater, what is the minimum combined relieving capacity permitted for the safety valves?

In determining the minimum combined relieving capacity for the safety valve on a gas-fired watertube boiler, specific formulas and regulations apply based on the boiler's heating surface area. Generally, the capacity of a safety valve is linked to the size of the heating surface and the type of fuel being utilized.

For watertube boilers, a common rule of thumb is to multiply the total square meters of boiler surface area by a standard factor that reflects the potential steam generation per hour. In this case, given the 70 m² of boiler surface, the calculation likely involves a factor around 116 kg/h per m², typically used for gas-fired boilers to estimate the requirements accurately.

By using the calculation:

70 m² × 116 kg/h/m² = 8120 kg/h

This calculated result rounds up to approximately 8130 kg/h, which aligns with the available answer choice. This ensures that the boiler is equipped with adequate safety measures to relieve steam pressure, preventing potential hazards due to overpressure situations.

Meeting or exceeding this capacity is crucial for operational safety and compliance with industry standards, ensuring that the safety valve can handle the worst-case scenario of pressure buildup effectively. Always following established codes, such as the ASME Boiler and Pressure Vessel