hp-Technik B-GHG-E/2 bypass oil valve

The hp-Technik B-GHG-E/2 is a bypass oil valve listed under the catalogue category of oil bypass valves. A bypass valve of this type is installed in the oil circuit between the pump and the nozzle assembly, allowing a portion of the fuel to return to the tank or to the pump inlet. This arrangement is necessary in single‑pipe systems where the burner must operate with a recirculation loop, or when the pump’s internal bypass is insufficient to maintain stable pressure across the nozzle. The valve acts as a pressure relief and flow regulator, ensuring that the oil delivered to the nozzle remains within the firing rate set by the burner control. Parts of this class are selected by the intended hydraulic configuration — single‑pipe or two‑pipe — and by the required capacity and pressure range. The connection threads and shaft orientation must match the mounting pattern on the pump body. When replacing a bypass valve, the heating engineer should verify that the valve’s opening pressure and flow characteristics are compatible with the pump’s output and the nozzle’s rating. A mismatched bypass valve can lead to unstable firing rates, poor cut‑off, or pump cavitation. Common failure modes include leaking seals, blocked bypass ports, or a stuck regulating piston, all of which affect the burner’s ability to maintain a consistent oil supply. The valve itself is a discrete component separate from the pump’s integral solenoid; its replacement does not affect the solenoid operation, but the overall system response may change if the bypass setting is altered.