Print this pageValve Closure
Valve operations are one of the most frequent causes of dynamic changes and surge pressures. So it is vital to study valve operations and to determine the impact of valve specification during design and whenever the operation of a system is changed.
The type of valve (globe, gate, ball etc) and the opening and closing speed of valves has a major impact upon the severity of the dynamic changes that are caused by closing and opening.
Changes to existing valves should be reviewed carefully because valve opening/closing speeds are sometimes specified precisely during design to prevent problems. Simply exchanging the valve for a newer model without also reviewing the type of valve selected and the operating speed can introduce problems.
Several ‘rules-of-thumb’ have been adopted in recent years (such as 1 second per inch) that can be as useful as dangerous. These simplified rules do not ensure safety nor do they ensure good control.
