Guide To Pool Heating

Page 48 of 51

EQUIPMENT AND PIPE SIZING FOR A HYDRAULICALLY
BALANCE POOL OR SPA

All calculations are based on the National Hydraulic Institute’s
recommendation of a pipe velocity of 7 feet per second (f.p.s.) or less.

Gallons

Pipe Size

Friction
Loss

Minimum
Size*
Sand Filter
(Sq Ft)

(Per Minute)
GPM

(Inches)

(For 100 Feet
of Pipe)

DE Filter
(Sq Ft)

Cartridge**
(Sq Ft)

301 - 1/411.120
40 1 - 1/28.927
501 - 1/213.533
6025.640
7027.447
8029.553
902 - 1/25.060
1002 - 1/26.167

*Filters calculated at most efficient flow rate.
**Dual Cartridge filters.

2.0
2.7
3.3
4.0
4.7
5.3
6.0
6.7

2 - 20
2 - 26
2 - 33
2 - 40
2 - 46
2 - 53
2 - 60
2 - 66

DETERMINING THE MAX FLOW RATE BY THE SIZE OF PIPING
GALLONS PER MINUTE FLOW RATE (GPM) @
7 FEET PER SECOND MAX FLOW VELOCITY

Pipe Size
(Inches)

Flow Rate
(GPM)

1
1 - 1/4
1 - 1/2
2
2 - 1/2
3

18
33
44
75
110
160