Nordyne 661021R Natural Gas Main Burner Orifice #21

The Nordyne 661021R Natural Gas Main Burner Orifice is a precision-machined flow control component to regulate natural gas delivery to the main burner assembly. It is installed in furnace burner manifold where it meters fuel through a calibrated #21 opening to maintain consistent flame feature. Within HVAC systems, it is used in gas-fired heating equipment to ensure controlled gas-air mixing at the burner stage supporting stable combustion inside the heat exchanger section. The orifice direct fuel flow into the burner ports maintains uniform ignition, and steady heat output during system operation.