Dynamic behavior of a tilting check valve

Valves are an important part of pipeline systems. They are used to regulate the flow and pressure, protect the pipes and pumps from over pressurization, prevent reverse flow through pumps, remove air and perform other functions. Check valve is installed in the suction line of pump arrangement to keep pump primed. Check valves also may be installed in discharge lines to minimize flow reversal, which can damage pumps and motors. Check valves should be open easily for forward flow, so they are stable under forward flow conditions and have a low flow loss coefficient. They close when the flow reverses so as not to generate undesirable transients in pipeline. With no flow in the system the valve remains closed or nearly closed due to the gravitational force and spring loaded disc. Tilting check valve is a type of construction of check valves. The basis of the tilting check valve is lifting a disc, pivoted on the periphery, with flow in one direction. The disc lifts and floats in the stream offering minimum resistance to flow. The disc tilt angle results from the balance of the disc weight and hydrodynamic forces. Wen the tilt angle tends to be very close to zero, the valve closes and in that moment a reverse flow and a sudden pressure rise occurs. The disc of the check valve is subjected to dynamic load due to the fluid striking the disc body. The dynamic load depends upon flow velocity and flow type. The dynamic force affects valve performance, decreases operating life, and increases flow loss coefficient. In this research, the dynamic characteristics of a tilting check valve is studied. A test setup is designed and modem instrumentation including spectrum analyzer, accelerometers, and vibration software are used to measure and analyze valve oscillations at different operating conditions.