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In a piping system, butterfly valves are often used as a
flow controller to either modulate the flow throttling range or
control the flow's on/off positions. Because butterfly valves
are usually light-weighted and low cost, they have a wide range
in size selection and possess a small flow resistance,
therefore, they are widely accepted in many industrial
applications. After a certain period of service, a
butterfly valve and its downstream pipe wall may be damaged by
erosion. The elimination or mitigation of this kind of erosion
problem is actually the most important issue for a valve user.
An experiment setup is used in this study to investigate the
erosion problem. The water tunnel is 3 inches in diameter and
the pipes are made by transparent PE for the ease of flow
visualization and photograph purpose. At certain key positions,
the pressure and flow vibration level are also measured to
support the observation of possible erosion phenomena. The
results indicate the most serious erosion problem may occur when
the valve open angle is between 20-40 degrees. In this
paper, five different valve disks are used to perform the tests,
the results shows the model 5 have the smallest vibration level
both on the valve stick and its downstream pipe wall under the
critical valve opening angle. These results implies that a
suitable buffer attached on the back side of disk surface near
the orifice side could mitigate the erosion phenomena.
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