The nominal diameter of the pipeline system is the determining factor when choosing a check valve cartridge . The aim is to reduce the pressure loss through the check valve cartridge to a minimum ( EN 13959 ). The pressure lost through a NEOPERL ® check valve cartridge is very low . Open cage constructions have lower pressure loss than closed body constructions . The valves are available with different springs varying in stiffness in order to comply with international standards . |
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1 Housing
2 External seal
3 Closing system – Spring – Plunger & seal – Guidance
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Operating principle |
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Static state ( no flow ) The check valve is closed . The spring presses the cone into its seat and keeps the valve closed . |
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Dynamic state ( flow ) The pressure of the water is higher than the spring pressure . The cone is pushed out of its seat and allows the water to pass . |
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Backflow ( flow in the opposite direction ) If the direction of flow changes as a result of an increase in pressure downstream of the valve ( backflow ) or a reduction in pressure upstream of the valve ( backsiphonage ), the spring allows the cone to snap back into its original position , closing the inlet side of the valve to prevent water flowing back . |
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38 | Check valves |