Brochure

Fisher
®
Cavitation-Control Technologies | 5
Emerson engineers conduct noise
and vibration tests on cavitating
applications in many different
ways. Transparent pipe allows
visualization of the cavitation
field. Cavitation demonstrations
can be arranged with your local
Emerson Process Management
sales office.
Excessive Noise and Vibration
Cavitation can cause unacceptable noise and vibration.
Although the noise associated with a cavitating liquid can be
quite high, it is usually a secondary concern when compared
to the material damage that can exist. Cavitation is frequently
described as sounding like gravel in a pipe, but the character of
cavitation noise can vary widely.
Damaging cavitation can take place without noise, and the
level of noise and vibration from a control valve may not
always coincide with the cavitation damage level.
Vibration resulting from cavitation may be more prevalent
than cavitation damage. It can affect the valve positioner,
linkage, tubing, and adjacent pipe.
Emerson Innovation
Fisher
®
Technology Development
The Emerson Innovation Center for Fisher Technology in
Marshalltown, Iowa, USA, is home to the world’s largest flow
lab used to evaluate control valves. It incorporates flow testing
capabilities up to NPS 36 and 240 bar (3,500 psig). Final
control elements are tested in conformance to IEC and ISA
standards in real-world plant conditions to ensure production
reliability, efficiency, environmental compliance, and safety.
Emerson engineers conduct tests that analyze cavitation,
materials, fatigue, wear, high and low temperatures, valve
actuators, valve instrumentation, seismic requirements,
reliability, loop variability, leakage, hydrostatic forces, gaskets,
seals, and control system compatibility. In the controlled lab
environment, special tests are commonly performed to answer
customers’ questions.
Normal, turbulent ow in a transparent pipe.
Cavitation and turbulent flow vary with pressure drops.
Note the variation in flow fields between this
image and the second image, despite identical
service conditions.