صمام تجاوز الزيت hp-Technik B-PP-Pro-2

An oil bypass valve of this type is installed in the oil supply circuit between the pump and the nozzle, or as a return line from the pump to the tank. Its function is to regulate the pressure at the nozzle by diverting excess oil back to the tank when the burner is operating. In two-pipe systems, this valve is often integrated into the pump or fitted externally; in single-pipe systems, a bypass plug or valve may be used to simulate a return line. The valve ensures a steady pressure for correct atomisation and prevents the pump from dead-heading when the burner shuts down. When selecting a bypass valve of this class, consider the pressure range it is designed to maintain, the connection thread size (for example, G1/4 or G1/8 depending on system), and the flow capacity. The valve may be preset or adjustable. During replacement, verify that the thread type, seal face, and mounting orientation match the existing port on the pump or pipework. Also check fuel compatibility if a preheater is used for heavier oils. Common failure modes include a stuck poppet, a leaking diaphragm, or spring fatigue, which cause pressure fluctuation at the nozzle and result in poor combustion or unstable flame. The bypass valve works together with the oil pump's internal pressure regulator and, in some burner layouts, with an integrated solenoid valve that the burner control energises to close the bypass during firing. When replacing, ensure that the valve does not obstruct access to the pump, preheater, or solenoid for service. Correct installation is essential for reliable cut-off and pressure stability across the firing range.