Sizing Guide

Guidelines for Sizing




90°

45°












1-1/4 3.5 1.8 2.3 6.9 11.5 0.9
1-1/2 4.0 2.2 2.7 8.1 13.4 1.1
2 5.2 2.8 3.5 10.3 17.2 1.4
2-1/2 6.2 3.3 4.1 12.3 20.3 1.7
3 7.7 4.1 5.1 15.3 25.5 2.0
Figure 5.

(A) STATIC HEAD
(B)TOTALLENGTHOFPIPING
(C)TOTALFRICTIONFACTORSOFFITTINGS
(D)   TOTAL(B+C)
(E) DIVIDED (D) BY 100
(F)HEADLOSSPER100FT.OFPIPE(fromFigure4)
(G)   FRICTIONHEAD(ExF)
(H)   TOTALHEAD(A+G)

Every centrifugal pump has a unique performance curve. This
curve illustrates the relationship of flow  to pressure
 at any point. The pump will operate at any point
along this performance curve.
Pump capacity is therefore the flow the pump will generate
at any specific pressure. The object is to select a pump whose
performance curve passes either through or close to the
designcondition,preferablyabove.RefertoFigure7.

  requirements may be determined by local
codes and/or by the type of application and types of solids
anticipated. Unless otherwise stated by codes, a sewage
pump should have the capability of handling spherical
solids of at least 2" in diameter in installations involving a
water closet.
Basin Size
Basin selection is best accomplished by relating to required
as determined by the  method.
Figure 6 shows recommended basin diameters, assuming the
normal pump differential (distance in inches between turn-on
and turn-off), and running time ranges from 15 seconds
to 4 minutes. Basin depth, however, shouldbe at least 24"
below basin inlet for most pumps and deeper where greater
pumping differentials are anticipated.
NOTE: Since basin size is directly related to frequency of
pump operation, it is important to select a basin of sufficient
size to ensure that the pump does not short cycle.
The question of whether to use a  or  system
dependsonthetypeofinstallationand/orlocalcodes.Generally,
a determination can be made using the following guidelines.
1. Domestic:  is usually adequate.
 2. Commercial: — Depending on the type of business
and the need for uninterrupted sanitary drainage facilities.
3. Public or Industrial:  is essential.
While you are sizing the system and before you select the
pump, you will need to know and consider or make allowances
for the following:
 • Volts/Phase/Hertz—Whatisavailable?
 • Willthepumpshareacircuit?
 • Doesthehome,business,etc.havecircuitbreakersorfuses?
 • WhatisthebreakerorfuseAmprating?Makesureitisenough.
 • Checklocalorstatecodesfor:
— Solid size requirements
— Amp ratings/circuit cord size/ratings or type
— Pipe material/size/depth to bury
— Tank size/location
 • Are there plans for future expansion? As in, adding
upstairs bath, basement plumbing, washing machine, etc.
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