Vanne de régulation Siemens VXP47.20-4

The Siemens VXP47.20-4 control valve, catalogue article 884.322.002, belongs to the category of gas valves. Parts of this type shut off and meter the gas supply to the burner. They open only when the burner control issues a command and the gas pressure switch confirms that the pressure is within safe limits. In premix burners, a pneumatic gas/air link ties the valve to the fan, ensuring the correct air‑to‑gas ratio. These valves are installed in the gas train, typically downstream of the gas filter and upstream of the burner nozzle or mixing unit. The coil is often replaceable separately from the valve body, which can simplify servicing. When selecting a replacement gas valve of this class, the key parameters are the brand and series, the connection size (commonly Rp 1/2" to 2" or flanged), the coil voltage (230 V or 24 V AC/DC), and the specific function required – single or double solenoid, slow‑opening, servo‑regulated, or a multiblock that also incorporates a filter and pressure regulator. The valve must be matched to the burner’s control system and the gas type (natural gas, LPG, etc.). A mismatch in voltage, connection size, or function will prevent correct operation or make installation impossible. Typical failures in gas valves of this type include coil burnout (often due to voltage spikes or overheating), leakage past the valve seat, drift in the outlet pressure setting, or a seized servo regulator. Before replacing the valve, confirm that the coil is receiving the correct voltage and that the gas pressure switch is functioning. If the valve body seats properly and the coil is intact, the servo regulator may be cleaned or replaced rather than the entire valve. Always observe gas safety regulations when working on the gas train.