Centrifugal Pumps Design and Application 2nd ed - Val S. Lobanoff, Robert R. Ross (Butterworth-Heinemann, 1992)

Chemical Pumps Metallic and Nonmetalllc 285
Figure 15-2. ANSI vertical in-line overhung single-stage pump with rigid coupling
(courtesy of ingersoll-Rand Company).
The specifications also stipulate that the pumps have centerline discharge
casings and should be pulled from the rear rotor design that allows
disassembly without disconnecting the suction or discharge nozzles.
To maximize mechanical seal life, the specifications require a .005-inch
shaft deflection limit at the impeller centerline due to dynamic deflection
and a maximum full indicator run out at the stuffing box face of .002
inches.
The specifications also require that there be a minimum bearing life of
17,500 hours due to the defined maximum imposed hydraulic loads and
that the suction and discharge flange pressure-temperature limits comply
to a minimum of ANSI B16.5 Class 150 (Figures 15-6 and 15-7).