Grundfos SQE 2 - 55 (96510151) [15/420] Well system pressure overload

English (GB)

8.3 Well system pressure overload

In order to provide protection against overpressure,

install a pressure relief valve downstream of the well

head. The setpoint of the pressure relief valve must

be at least 30 psi above the pressure setting.

If you install a relief valve, we recommend that you

connect it to an appropriate drainage point.

Using Pmin and Qmax, the minimum diaphragm

tank size, precharge pressure and pressure switch

settings can be found in the guideline table below:

Example

Pmin = 35 m head, Qmax = 2.5 m

/h.

On the basis of this information, the following values

can be found in the table:

Minimum diaphragm tank size = 33 litres.

1 m head = 0.098 bar.

Ppre = 31.5 m head

Pcut-in = 36 m head

Pcut-out = 50 m head

Pmin

[m]

Qmax [m

/h]

Ppre

[m]

Pcut-

[m]

Pcut-

out

[m]

0.6 0.8 1 1.2 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8

Diaphragm tank size [litres]

25 8 8 18 18 18 18 24 33 33 50 50 50 50 80 80 80 80 80 22.5 26 40

30 8 8 18 18 18 24 33 33 50 50 50 50 80 80 80 80 80 27 31 45

35 8 181818182433335050508080808080 31.5 36 50

40 8 1818181824335050508080808080 36 41 55

45 8 18181824333350505080808080 40.5 46 60

50 8 181818243350505080808080 45 51 65

55 18 18 18 18 24 33 50 50 50 80 80 80 49.5 56 70

60 18 18 18 18 24 33 50 50 80 80 80 80 54 61 75

65 18 18 18 24 24 33 50 50 80 80 80 80 58.5 66 80