Which factor is not used to size gas regulators?

Which factor is not used to size gas regulators?

• A. Type of gas
• B. Inlet pressure
• C. Required flow
• D. Type of ignition system

Answer: (D)

Regulator sizing is determined by what the appliance needs in normal operation: the type of gas being used, the available inlet pressure, and how much gas the appliance must flow to meet its rating. The regulator must maintain a specific outlet pressure and supply the maximum expected flow even as inlet pressure varies. The type of ignition system doesn’t set these steady-state requirements; it mainly affects how the flame is started and, at most, any brief startup gas demand. Those startup transients are not the basis for sizing the regulator, so ignition system type isn’t used in the sizing calculation.

Regulator sizing is determined by what the appliance needs in normal operation: the type of gas being used, the available inlet pressure, and how much gas the appliance must flow to meet its rating. The regulator must maintain a specific outlet pressure and supply the maximum expected flow even as inlet pressure varies. The type of ignition system doesn’t set these steady-state requirements; it mainly affects how the flame is started and, at most, any brief startup gas demand. Those startup transients are not the basis for sizing the regulator, so ignition system type isn’t used in the sizing calculation.