Kromschroder Air/gas ratio control GIK20R02-5 03155122

This air/gas ratio control, model GIK20R02-5 (SKU 03155122), is a pressure ratio regulator that maintains a 1:1 gas/air ratio. It has an Rp ¾" internal thread connection (nominal diameter 20 mm) and a maximum inlet pressure of 200 mbar. The outlet pressure range is 0.2–119 mbar, with a turndown of 1:10. It is suitable for natural gas, liquefied gas, and air, and is certified to EN 88 and CE. The superseded number for this item is 03155068.

Air/gas ratio controls of this type are selected by matching the burner manufacturer's design, connection size (threaded from Rp 1/2" to 2" or flanged), and the required pressure range. Before ordering, measure the existing connection thread and compare the rated inlet and outlet pressures. Verify whether the unit is purely pneumatic or includes an electronic actuator, and check that features such as zero-pressure regulation or proportional band adjustment match the original configuration. During installation, ensure the gas supply is clean and the incoming pressure does not exceed the control's maximum rating.

Common failures in air/gas ratio controls include diaphragm perforation or stiffness, spring fatigue that alters the set point, and debris blocking the pressure-equalising passages. A drifting ratio can lead to incomplete combustion or flame instability. The control body is usually replaced as a whole; internal parts are seldom serviced separately. Check for these issues if the burner exhibits unstable flame or elevated CO emissions.