Kromschroder Gas pressure switch DG30U-6T 84447294

The Kromschroder DG30U-6T is a mechanical diaphragm pressure switch designed to monitor pressure changes in gases or air, responding to rising or falling pressure relative to a setpoint. It features a pressure range of 2.5–30 mbar and switches via a microswitch with a switching contact when the trigger level, adjusted by a handwheel, is reached. The switch is silicone-free, with an NBR diaphragm and a housing made of glass fibre reinforced PBT plastic, while the lower housing section is AlSi 12. It has a 4-pin plug with socket, screw terminals, and a blue pilot lamp for 220/240 V AC, with a line entrance of M16 x 1.5. This model is safety class 1 and suitable for natural gas, town gas, LPG (gaseous), flue gas, biogas (max. 0.1% H2S), and air.

When selecting a replacement pressure switch of this type, verify the pressure range, switching function (rising or falling), and electrical connection (e.g., plug type, voltage) match the original. Check the process medium compatibility and ensure the switch is suitable for the gas or air application. Mounting typically involves connecting the pressure line to the appropriate port and securing the electrical connections; confirm the line entrance thread size and clamping range for the cable. Always compare the setpoint adjustment range and any safety approvals with the system requirements before installation.

Common failures of diaphragm pressure switches include diaphragm rupture or leakage, leading to loss of pressure sensing and failure to switch at the setpoint. This may cause the burner or boiler to operate outside safe pressure limits, potentially triggering lockouts or erratic operation. Electrical contact issues, such as worn or corroded contacts, can result in intermittent switching or no switching at all. Check for physical damage, leaks, and verify the switch operation by applying pressure and measuring continuity.