Page 146 - Improving Machinery Reliability

118 Improving Machitiery Relinbiliry

pulsations in the reciprocating pump system at selected locations are given in Figure
3-31. These pulsation levels define the energy in the pump and the piping shaking
forces, and can be used to define the necessary piping supports and span lengths to
achieve acceptable vibration levels. The program can be used to redesign the piping
to reduce the pulsations to acceptable levels.

Summary and Conclusions

Rigorous rotordynamic analyses must be thought of as additional insurance that the
machinery will run without major problems. Many of the analysis procedures and
computer programs that have been developed are being used by both the manufactur-
er and by consultants who offer these design audit services. As with many computer
programs, the interpretation of the computer results is dependent upon the skill and

2

Figure 3-31. Predicted pulsations in pump and piping system for pump speed range of
170-260 rpm.