Kromschroder Gas pressure switch DG50H-3 84447620

The Kromschroder DG50H-3 is a mechanical diaphragm pressure switch designed to monitor pressure changes in gas or air systems. It switches or locks off with rising pressure within an adjustable range of 2.5 to 50 mbar. The switch is suitable for natural gas, town gas, LPG (gaseous), flue gas, biogas (max. 0.1% by vol. H2S), and air. It features a glass fibre reinforced PBT plastic housing with a lower section of AlSi 12, an NBR diaphragm, and is silicone-free. Electrical connection is via screw terminals with an M16 x 1.5 cable gland, and the device has an IP54 protection class. The maximum medium and ambient temperatures are -15 to 60 °C, with a storage temperature of -20 to 40 °C. Weight is 0.321 kg.

When selecting a replacement pressure switch of this type, verify the adjustable pressure range, medium compatibility (gas or air), and electrical connection requirements. Check the line diameter (0.5–1.8 mm) and the cable gland size (M16 x 1.5) to ensure a proper fit. The switch must be mounted in the correct orientation and connected to the pressure line according to the manufacturer's instructions. Ensure the ambient and medium temperatures are within the specified limits to avoid premature aging of elastomer components.

Common failure modes for diaphragm pressure switches include diaphragm rupture or leakage, which can cause the switch to fail to actuate at the set point or to leak gas. Symptoms on the equipment may include burner lockouts, inconsistent pressure readings, or failure to detect pressure drops. Check for visible damage to the diaphragm, verify the set point with a manometer, and inspect the electrical contacts for corrosion or wear.