Kromschroder Gas pressure switch DG150UG-3 84447520

The Kromschroder DG150UG-3 is a mechanical diaphragm pressure switch with an adjustable range of 30–150 mbar. It is designed for monitoring gas or air pressure, suitable for natural gas, town gas, LPG (gaseous), flue gas, biogas (max. 0.1% by vol. H2S), and air. The switch operates with rising pressure and features a glass fibre reinforced PBT plastic housing with an AlSi 12 lower section, an NBR diaphragm, and IP65 protection. It has screw terminals and an M16 x 1.5 line entrance, and is silicone-free with low gas release. Safety class is 1, and it is suitable for medium and ambient temperatures from -20 to +80 °C.

When selecting a replacement pressure switch of this type, verify the pressure range, connection thread size, and electrical ratings match the original. Check the switching function (rising or falling pressure) and the medium compatibility. Ensure the enclosure rating and safety class meet the application requirements. Measure the line entrance thread and cable gland size to fit existing conduit.

Common failures include diaphragm rupture or leakage, leading to loss of pressure sensing and improper burner operation. Contacts may become worn or corroded, causing intermittent or no switching. Symptoms on equipment include failure to start, unexpected shutdowns, or erratic pressure control. Check for gas leaks, visual damage, and verify switch operation with a manometer.