Submittal Sheet

Pump and system sizing instructions
Unilift CC, KP, AP
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6. Simplex or duplex System
Local plumbing codes will often determine whether a
wastewater pumping system must be duplex (two
pumps), or whether a simplex system (one pump) is
sufficient. Most commercial applications are of the
duplex type, however - not necessarily for the
increased capacity offered by two pumps, but more for
the standby safety factor that many municipalities
require (public health concerns). In most residential
installations, a simplex system is adequate - but be
sure to check the local plumbing codes.
Additional information on pipe volume and flow
velocity:
Storage of water in pipes of various sizes
Minimum flow rate to maintain 2 ft/sec* flow velocity in
various pipes
* Failure to maintain or exceed this flow velocity will result in clogged
pipes. Information is based on Schedule 40 nominal pipe.
Pipe size
[inches]
Volume
[gallons per
foot]
Pipe size
[inches]
Volume
[gallons per
foot]
1.25 0.06 6 1.4
1.25 0.09 8 2.6
2 0.16 10 4.07
3 0.36 12 5.87
4 0.652
Pipe size
[inches]
Minimum flow
rate
[GPM]
Pipe size
[inches]
Minimum flow
rate
[GPM]
1.25 9 6 180
1.25 13 8 325
2 21 10 500
3 46 12 700
4 80