Machinery Components |
Click pictures to enlarge: |
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Pressure Reduction Valve |
Click pictures to enlarge: |
These data were collected
from a Linear Variable Differential Transformer (LVDT) which
measures very small linear distances. The LVDT was installed between two mechanical components that were
moving when they should not have been. The
data show that these components moved from +.010" to -.171", when
there should have been no movement at all. This type of relative movement may indicate
that the machine is undergoing stresses beyond its designed levels. |
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These pressure data were collected from
a city water line just down-stream
from a pressure reducing valve (PRV). The data show rapid pressure
fluctuations of as much as 56 PSI. These rapid pressure changes indicate
that the PRV is failing to regulate the pressure properly. They cause
water hammer or
banging in the pipe, and may cause damage to the pipe and joints. |
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A closer look at the data (highlighted
in purple in the picture above) shows very rapid motion. The spikes
in the LVDT readings were occurring as fast as 42 mSec apart. This
is not a periodic vibration, but movement due to operating
conditions. If this condition persists, it can result
in metal fatigue and failure. |
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Zooming in on the middle set of spikes from the
graph above produces this graph. It shows that the spikes are
occurring at approximately 600 ms intervals. |
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