Page 203 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

174 Applied Process Design for Chemical and Petrochemical Plants
2 N.P.T's for Circulating
Lubrication

- Figure 3-26. Circulating lubrication. (By permission, H. P. Hummer
.!!!
'S and W. J. Ramsey, Bulletin SD 752, O&T, Durametallic Corp.)
0
,::,
c: r---------7-
c:,
- ... Product Recirculating, Flushing, I External Fluid Flushing
or By-pass from Discharge
-=
,:r
c:
0
0
...
-
<...)
0

Figure 3-24. Gland plate cooling. (By permission, H. P. Hummer and
W. J. Ramsey, Bulletin SD 752, O&T, Durametallic Corp.) Figure 3-27. Flushing inside seal. (By permission, H.P. Hummer and
W. J. Ramsey, Bulletin SD 752, O&T, Durametallic Corp.)

I N.P.T. for Dead-End .-------7
Lubrication Product Recirculating, Flushing, I External Fluid Flushing
or By-pass from Discharge
r-----1.'_ I N.P.T. for Flushing
; Connection
,I

Figure 3-25. Dead-end lubrication. (By permission, H. P. Hummer Figure 3-28. Flushing outside seal. (By permission, H. P. Hummer
and W. J. Ramsey. Bulletin SD 752, O&T, Durametallic Corp.) and W. J. Ramsey, Bulletin SD 752, O&T, Durametallic Corp.)

Generally speaking the centrifugal pump has these char- 6. Develops turbulent conditions in fluids
acteristics: 7. Turbine type: (a) offers very high heads al low flows,
(b) self-priming, (c) limited Lo very clean, non-abra-
1. Wide capacity, pressure, and fluid characteristics sive fluids with limited physical properties, (d) clear-
range ances can be problem on assembly and maintenance.
2. Easily adapted to direct motor, V-belt or other drive
3. Relatively small ground area requirements Single-Stage (Single Impeller) Pumps
4. Relatively low cost
5. Difficult to obtain very low flows at moderate to high This type of pump (Figures 3-1, 3-2, 3-3) is the work-
pressures horse of the chemical and petrochemical industry. It also