Pentair Siata V132 SFE Installer Manual page 24

Installer manual Siata V132 - SFE - System sizing
Depending on the inlet water hardness, the service velocity for standard softening has to be between:
Service velocity
[bed volume per hour]
8 - 40
8 - 30
8 -20
A
Note
Failure to respect the service velocity will lead to hardness leakage or even total softener
inefficiency.
Note that the water supply piping size may also be useful when estimating the nominal flow rate, since
the size of the piping allows a maximum flow rate to pass. Assuming the maximum velocity of water
in pipes is about 3 m/s, a good estimation for most common pressure [3 bar] and temperature [16°C]
is:
Piping size (internal diameter)
[in]
0.5
0.75
1
1.25
1.5
2.0
2.5
3.0
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Inlet water hardness
[mg/l as CaCO ]
3
< 350
350 to 450
> 450
[mm]
12
20
26
32
40
50
63.5
76.2
Ref. MKT-IM-003 / B - 19.04.2017
°F
°dH
°TH
<35 <19.6
35 - 45 19.6 - 25.2
>45 >25.2
Max. flow rate
3
[m /h at 3 m/s]
1.22
3.39
5.73
8.69
13.57
21.20
35.2
49.2