Kromschroder Air pressure switch DL4K-3TZ 84444701

The Kromschroder DL4K-3TZ (SKU 84444701) is an air pressure switch designed for monitoring overpressure, vacuum, and pressure drop in air or flue gas systems. It features a glass fibre reinforced PBT plastic housing and a tempered LSR diaphragm system. The switch operates within a temperature range of -20 to +80 °C and weighs 200 g. It meets safety class II to VDE 0106-1 and is compliant with EN 61058-1 for the micro switch, as well as EN 13611 and EN 1854 standards. The designed lifetime is 10 years from the manufacturing date.

When selecting a replacement pressure switch of this type, ensure the medium (air or flue gas) and the pressure range match the application. Verify the electrical ratings and switching function (normally open or closed) required by the control circuit. The mounting orientation and connection size must be compatible with the existing piping. Always check the ambient and medium temperature limits to ensure suitability.

Common failure modes for air pressure switches include diaphragm rupture, contact welding, or loss of calibration. Symptoms may include burner lockout, failure to start, or erratic operation. Check for leaks in the pressure lines, verify the switch actuation point with a manometer, and inspect the diaphragm for damage or debris.