Kromschroder Air/gas ratio control VAG115R/NWBE 88000141

The Kromschroder VAG115R/NWBE (SKU 88000141) is an air/gas ratio control with an integrated solenoid valve, designed for modulating and step-controlled burners. It maintains a precise gas/air ratio, typically 1:1, to ensure efficient combustion. The valve has a nominal diameter of 15 mm with a Rp 1/2 connection thread, and it operates with a maximum inlet pressure of 500 mbar. It requires a supply voltage of 230 V at 50 Hz, and its integrated solenoid valve performs shut-off and regulating functions. This model includes a blue indicator and a reduced valve seat, as indicated by the NWBE version.

When selecting a replacement air/gas ratio control of this type, verify the connection size (e.g., DN 15 with Rp 1/2 thread) and the maximum inlet pressure rating to match the existing gas train. The electrical supply (voltage and frequency) must correspond to the burner control system, and the integrated solenoid valve's configuration should be compatible. Check the control range and any adjustment mechanisms, such as external screws or servo motors, to ensure they align with the burner's requirements. Installation involves mounting the valve in the gas train between the main shut-off valve and the burner, and connecting the impulse line from the fan or air damper to the valve's pressure port.

Common failures in air/gas ratio controls include diaphragm fatigue, which causes an offset in the gas/air mixture, leading to incomplete combustion or flame instability. Blockage of the pressure impulse line can result in erratic gas flow or failure to modulate correctly. Seizure of the internal regulator due to debris may cause the valve to stick, preventing proper gas flow control. Symptoms on the equipment include fluctuating flame, increased emissions, or burner lockout. Check the diaphragm, impulse tubing, and internal components for wear, blockage, or damage.