FRED R. SZENASI
CECIL R. SPARKS
J. C. WACHEL
The major concern regarding pump noise falls into two categories:
1. Noise levels that do not meet applicable environmental criteria. Examples range from
personnel noise exposure criteria to overside noise criteria for submarines.
2. Noise signatures that can be used to diagnose faulty pump operation or incipient
The proliferation of industrial noise regulations in recent years has taken much of the
guesswork out of allowable noise levels insofar as personnel and community exposure is
concerned, and various noise standards have specified noise measurement techniques.
Several organizations have developed test procedures and codes for machinery-generated
noise levels.1,2 The Hydraulic Institute code was specifically developed for the measure-
ment of airborne sound generated by pumps (Reference 3).
The most common approach for controlling airborne noise levels from pumps is to
interrupt the paths by which noise reaches the listener. When noise is an indicator of
abnormal pump operation, modification of pump internals or operating conditions is nor-
The measurement of noise for diagnostic purposes is not well prescribed, either for
instrumentation or for interpretation. Even a well-designed and properly operated pump
will of course produce noise. Variations in noise amplitude and frequency that result from
malfunction or improper operating conditions will depend upon the type and design of the
pump and the type of problem causing the noise. Measurement and analysis techniques
for interpreting these signatures will depend upon whether the noise is solid-, liquid-, or
airborne and upon the nature of coexisting noise from other sources.
Determining the source and cause of noise is the first step in evaluating whether noise
is normal or an indicator of possible problems. Noise in pumping systems can be generated
both by the mechanical motion of pump components and by the liquid motion in the pump