Air/gas ratio regulator
PRG series Hauck

Hauck RRG regulators are carefully factory balanced to maintain a precise gas-air ratio for nozzle mix burners which use low pressure air and gas. When cross-connected to a control air line (see typical piping schematic), these regulators automatically proportion the gas delivery pressure in response to varying air pressure in the air control zone, enabling single valve firing control.

The proper operation of a cross-connected gas regulator requires that the gas supply pressure be equal to the sum of the maximum control air line pressure plus the gas pressure drop through the regulator at high fire. If the gas pressure is high enough, an air bleeder valve is not required. If the gas pressure is too low or the air pressure is too high, an air bleeder valve is required in the air control line.