Vanne de régulation Siemens VXG44.15-2.5
The Siemens VXG44.15-2.5 is a catalogue item listed under gas valves. Parts of this type serve to shut off and meter the gas supply to the burner. They open on command from the burner control and only when the gas pressure switch has confirmed adequate gas pressure; in premix boilers a pneumatic gas/air link ties the valve to the fan. Control valves such as this are selected by brand and series, connection size (typically Rp 1/2" to 2" or flanged versions), coil voltage (common options 230 V or 24 V AC/DC), and function (single or double solenoid, slow opening, servo-regulated, or a multiblock that incorporates a filter and regulator). The coil is often replaceable separately from the valve body, which simplifies servicing. In a boiler or burner system, the gas valve sits between the gas pressure switch and the burner control. During the ignition sequence, the burner control opens the valve after pre-purge and spark initiation, then relies on the ionisation electrode or flame detector to confirm the flame within the safety time. A faulty valve can lead to failure to open, leakage, or unstable outlet pressure, causing lockout or unsafe operation. When replacing a control valve, verify that the replacement matches the original in connection type, voltage, and intended function, and check that the coil is compatible if the body is reused.