Kromschroder Gas pressure switch DG500U-6 84447551

The Kromschroder DG500U-6 is a diaphragm pressure switch with a pressure range of 100–500 mbar. It is designed for monitoring pressure in gas or air systems, suitable for natural gas, town gas, LPG (gaseous), flue gas, biogas (max. 0.1% by vol. H2S), and air. The switch operates with rising positive pressure (gas/air), negative pressure (air), or differential pressure (air-air). It features a glass fibre reinforced PBT plastic housing with low gas release, an NBR diaphragm, and a lower housing of AlSi 12. The electrical connection is via a 4-pin plug with socket, and it includes screw terminals. This silicone-free device has safety class 1 and is suitable for medium and ambient temperatures from -20 to +80°C, with storage temperature from -20 to +40°C.

When selecting a replacement pressure switch of this type, verify the required pressure range, electrical connection type (e.g., plug or terminals), and line entrance thread (e.g., M16 x 1.5). Ensure the switch is compatible with the medium (gas or air) and the pressure direction (rising, falling, or differential). Check the enclosure rating (IP54 or IP65) and safety class to match the application. Before installation, confirm the line diameter and clamping range for the cable, and ensure the switch is silicone-free if required.

Common failure modes for diaphragm pressure switches include diaphragm rupture or leakage, leading to loss of pressure sensing or false switching. Symptoms may include the burner failing to start, unexpected shutdowns, or erratic operation due to incorrect pressure readings. Check for leaks around the diaphragm and housing, and verify the switch operation by testing with a manometer. Regular maintenance, including annual tightness and functionality checks, is recommended to ensure proper operation.