For a single natural gas burner requiring 70,000 BTU/hr input at 3.5" w.c. pressure, what size orifice would you choose?

To determine the correct orifice size for a single natural gas burner requiring 70,000 BTU/hr input at a pressure of 3.5" w.c., one must consider the relationship between the gas flow rate, the burner rating, and the orifice diameter.

In this context, BTU/hr is a measure of the energy output of the burner, while the pressure in inches of water column (w.c.) provides insight into the force driving the gas through the orifice. Each orifice size corresponds to a specific flow capacity at a given pressure.

For a burner with a requirement of 70,000 BTU/hr at 3.5" w.c., an orifice size of #22 is typically selected as it can adequately handle the gas flow needed to meet the burner's specifications. This selection indicates that the #22 orifice will facilitate the right mixture and volume of natural gas combustion for optimal performance, ensuring efficient burning while remaining within safe operation standards.

Choosing the wrong orifice size may either result in insufficient gas flow (leading to incomplete combustion) or excessive gas flow (potentially causing safety hazards due to elevated gas pressures). The #22 orifice strikes the right balance for this specific application, thus confirming