Kromschroder Gas pressure switch DG50B-3 84447200

The Kromschroder DG50B-3 is a diaphragm pressure switch designed to monitor pressure fluctuations in gas or air environments, responding to rising positive pressure. It has an adjustable pressure range of 2.5 to 50 mbar and is suitable for use with natural gas, town gas, LPG (gaseous), flue gas, biogas (max. 0.1 %-by-vol. H2S), and air. The switch features a glass fibre reinforced PBT plastic housing with a lower housing section of AlSi 12, an NBR diaphragm, and is silicone-free with low gas release. It has screw terminals, an M16 x 1.5 line entrance, and a line diameter of 0.5 to 1.8 mm. The device is IP54 rated, safety class 1, and weighs 0.321 kg. It complies with EN 13611:2015+AC:2016 and EN 1854:2010 standards, with CE product ID CE-0085AP0467 and notified body 0085.

When selecting a replacement pressure switch of this type, verify the pressure range, electrical connection type (screw terminals), and line entrance thread (M16 x 1.5) match the existing installation. Ensure the switch is suitable for the medium (gas or air) and that the enclosure rating (IP54) meets the environmental requirements. Mounting is typically via a threaded connection; check the line diameter (0.5–1.8 mm) and clamping range (4–10 mm) for the cable gland. Confirm the switch is set to the correct trip point before installation.

Common failure modes for diaphragm pressure switches include diaphragm rupture or leakage, which can cause the switch to fail to actuate or to actuate at incorrect pressures. Symptoms on equipment may include burner lockout, erratic operation, or failure to start. Check for gas leaks around the switch, verify the diaphragm integrity, and test the switch operation against a known pressure source.