The Development Of Diaphragm Valve For Fixed Roof Tank

Diaphragm valve for fixed roof tanks is an internal and external pressure balance safety device for fixed-roof tanks to adapt all kinds of pressure changes in use. By using the requirements analysis, theoretical analysis, experimental analysis, virtual prototyping simulation and physical prototype testing methods, the construction of diaphragm valve has been designed and optimized, the performance of its core components, the diaphragm, has been analyzed, after synthesizing various factors which leading to gas space pressure change in the top of oil tank, combined with design methods and research ideas of domestic and overseas breathing valve, rupture disc product.The prototype has been developed. The main research is presented as follows:Firstly, requirements and design goals of diaphragm valve are made by analyzing factors affecting the safety of tanks in use; the device construction is determined and aluminum and rubber sheets are selected as the diaphragm used in valve after comprehensively synthesizing the current overpressure relief device.Secondly, the mechanical properties of the membrane which is the core element of the safety valve diaphragm are analyzed, including the pressure- center displacement curves and fatigue life by using the finite element software ANSYS to bulid a rational numerical simulation model, based on the large deformation theory and the theory of fatigue life. The results present that rubber diaphragm has relatively large compressive deformation and good fatigue resistance compared with aluminum sheet.Thirdly, a diaphragm compression deformation test platform is built according to the measurement requirements. Displacement of center point of different thickness diaphragm, including aluminum diaphragm, ordinary rubber diaphragm, rubber diaphragm after simulation environment treated, are measured in different pressure. And ultimately 0.4mm thickness of the rubber diaphragm is chosen as the diaphragm for valve diaphragm by analysising the diaphragm compression deformation capacity and environmental adaptability,.Finally, a new diaphragm valve prototype is developed after improving puncturing device of diaphragm valve by establishing three-dimensional model, checking interference, verifying the mathematical model based on Pro / E.