Kromschroder Gas pressure switch DG500UG-4 84447040

The Kromschroder DG500UG-4 gas pressure switch, SKU 84447040, is a diaphragm-type pressure switch designed to monitor pressure changes in gas or air environments. It operates with positive, negative, or differential pressure and has an adjustable range of 100–500 mbar. The switch features gold-plated contacts, screw terminals, and a glass fibre reinforced PBT plastic housing with a lower housing of AlSi 12. It is silicone-free, has low gas release, and meets safety class 1. The diaphragm is made of NBR, and the line entrance thread is M16 x 1.5.

When selecting a replacement pressure switch of this type, ensure the pressure range, electrical connection type, and thread size match the original. Verify the medium compatibility (e.g., gas or air) and the required pressure type (positive, negative, or differential). Check the mounting orientation and available space for the housing. Confirm the electrical ratings and that the switch is suitable for the system's safety requirements.

Common failures of diaphragm pressure switches include diaphragm rupture or leakage, which can cause the switch to fail to actuate or to actuate at incorrect pressures. Electrical contact wear or contamination may lead to intermittent or no signal. Symptoms on equipment include burner lockout, erratic pressure readings, or failure to start. Check for physical damage, verify the setpoint with a manometer, and inspect the electrical continuity.