Abstract Direct spring operated pressure relief valves are regular elements of high-pressure hydraulic systems; however, valve vibrations may still occur endangering the and protected system. The damping these is a crucial issue, whereas external viscous at cannot be increased boundlessly based on safety aspects. emerge via Hopf bifurcations either super- or subcritical type, nonlinear characte...

Water-hammer is a transient condition which may occur in a network as a result of rapid or slow valve closures, pump failures, changes in turbine loading, etc. It creates high and low pressure waves which travel along the system and decay as a result of wall shear stress. Comparison o experimental and theoretical results revealed the failure of steady or quasi-steady models in correctly predict...

Calcific aortic valve disease encompasses a range of disease severity from mild leaflet thickening without valve obstruction, called “aortic sclerosis,” to severe aortic stenosis. It is intuitive that severe obstruction in blood flow at the valve level results in poor clinical outcomes and that relief from the obstruction by valve replacement corrects the problem. However, we now recognize that...

Water-hammer is a transient condition which may occur in a network as a result of rapid or slow valve closures, pump failures, changes in turbine loading, etc. It creates high and low pressure waves which travel along the system and decay as a result of wall shear stress. Comparison o experimental and theoretical results revealed the failure of steady or quasi-steady models in correctly predict...

The relation between the size of the balloon used for dilatation of the pulmonary valve and the extent of relief of pulmonary stenosis both immediately after and at intermediate term follow up was studied. Sixty four balloon dilatation procedures in 56 patients were divided into group 1-12 in which the ratio of the diameter of the balloon to that of the pulmonary annulus was less than or equal ...

In water supply systems, One of the most important components as safety unit and the current controller (Switching flow and regulate the amount of flow) used in the arrangement of lines of water. In this study, according to multiple ponds in Tanguiyeh dam water pipeline to industrial and mining company Gol Gohar Sirjan Butterfly valve used in these ponds using Fluent software simulation has bee...