Kromschroder Diaphragm 74924631

This working diaphragm is a spare part for Kromschroder VGBF 80..40 /B, VAR 80 /B, and GIK 80 /B gas regulators. It converts pressure differential into mechanical force to move the valve, ensuring stable output pressure. Made of Perbunan (NBR), it is compatible with natural gas and liquefied gas (propane-butane) at inlet pressures up to 4000 mbar. The net weight is 0.304 kg; the item is manufactured in Germany and carries a 1-year warranty.

Parts of this type are selected by the exact valve series and the manufacturer's part reference; cross-referencing by the original part number is essential because different series use diaphragms of differing dimensions and material grades. Before ordering, compare the valve series and part reference to the original. During installation, ensure the new diaphragm is seated evenly and that any centering pins or springs are correctly positioned before reassembly.

When a diaphragm of this type deteriorates due to material fatigue, contamination, or overpressure, the valve may show a drifting outlet pressure, fail to open fully, or leak at the seat. In gas pressure and ratio regulators, this can result in lockout from insufficient gas pressure or unstable combustion, especially during modulation. Inspect the valve seat and diaphragm support for scoring or debris when such symptoms appear.