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

82 Centrifugal Pumps: Design and Application
Suction Layout (End View)
See Figure 1-2 for a diagram of the layout.
1. Draw a circle DI at point O.
2. Locate Sections 1 through 7 from Table 7-1.
3. Locate Section A-B perpendicular to flow, approximately D s dimension
from O. For length of A-B use Table 7-1.
4. Locate nozzle dimensions L and S and mark off nozzle diameter.
Dimension L should be only long enough for gradual area progression
and clearance behind the flange bolting. This clearance becomes
more critical on horizontally split pumps, where nozzle bolting
may interfere with the parting flange,
5. Connect all points freehand.
6. Locate Section C-D somewhere between A-B and nozzle.
7. Layout volute metal line.
8. Lay in chords PI, Pa, and P 3 to mid point of A-B, C-D, and nozzle
respectively.
Suction Layout (Profile)
See Figure 7-3 for a diagram of the profile.
!. Layout impeller shape, including shaft and sleeve.
2. Layout volute shape and metal line at intersection of chord Pa-
3. Layout volute shape in dotted lines at location X to observe maximum
blockage.
4. Curve metal line around volute sections into the impeller eye,
maintaining minimum metal thickness.
5. Mark off chord lengths PI, ?2, and P 3 .
6. Locate nozzle diameter.
7. Approximate width of A' - B' and C' - D' to satisfy area progression
from Figure 7-4.
8. Connect outer wall points freehand with ample curvature into impeller
eye.
9. Lay in Sections 1 through 7. In this example only Section 1 is
shown.
10. Develop Sections A-B and C-D as surfaces of revolution (Figure
7-5). Sections can be divided into any number of increments (e.g.,
PA and PB). Transfer these chords from the end view to the profile,
measure dimensions P' - A' P' - B' and transfer to section
layout.