Kromschroder Gas pressure regulator VGBF25R40-1 86046010

This is a gas pressure regulator for burner and boiler gas trains. It maintains a constant outlet pressure within the set range of 5–350 mbar, even when inlet pressure or flow demand varies. The regulator has a threaded connection of Rp 1" and accepts a maximum inlet pressure of 4000 mbar. Its body is made of aluminum alloy, and the diaphragm is made of perbunan. It includes a safety feature with zero shut-off and a safety diaphragm, as well as a compensation diaphragm for inlet pressure differences. It is intended for ambient temperatures from -15 to 60 °C and requires that the gas must not condense.

Parts of this type are selected by connection size, pressure range (minimum and maximum inlet, adjustable outlet), and flow capacity required by the burner. Before ordering, verify that the connection threads match the existing pipework and that the regulator is rated for the gas type used (natural gas, LPG, etc.). Install the regulator downstream of the gas shut-off valve and upstream of the burner controls, with the flow direction indicated on the body. Ensure the pressure adjustment screw is accessible and, after installation, test the outlet pressure with a manometer.

Common failure modes for this type of regulator include dirt in the seat, which causes outlet pressure drift, and a seized diaphragm due to ageing, leading to unstable pressure or no gas flow. A faulty regulator may cause the burner to fail to ignite or to operate at an incorrect pressure, potentially triggering a gas pressure switch. Check the outlet pressure with a manometer, inspect the seat and diaphragm for contamination or damage, and verify the set-point adjustment.