Pumping & Pipe Friction Losses

Pressure Pump Systems

Extract from

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Many people have a rain water tank below the level of the plumbing in the house. Even if the tank is above this level it may not be high enough to supply water under sufficient pressure for household requirements. You may also need to have an on demand watering system for drinking troughs for animals or for irrigation.

There are four ways to supply water under increased pressure:

1. Solar array (one or more photovoltaic panels) connected direct to a low voltage pump to fill a header tank. This way there are no switches or batteries needed although an optimiser (or maximiser) is required. The pump only works when there is sufficient sunlight falling on the solar array to provide enough electricity.

2. Pump connected to the battery bank with a manual switch. If you already have a battery bank with charging system to hook into, this is the cheapest alternative. If your water outlet is above the water level in the tank you don't even need a tap. All you need is an open pipe with a switch near it.

3. Pump to a header tank with battery power. You can use a manual switch, a switch with a timer incorporated, a float switch which switches the pump on when the water in the header tank is low, or by using a pressure pump (option 4) and a float valve on the header tank so that the water is replaced in the header tank as it is used.

4. A pump to supply constant pressure with the use of a pressure tank and pressure switch. As soon as any tap is turned on the pressure tank releases some of its pressure to start the water flowing. At the reduced pressure the pressure sensitive switch then switches to turn on the pump. The pump then supplies the water and re-pressurises the pressure tank.

Important:

  1. You need to ensure that the pump never runs dry.
  2. It is recommended to use an accumulator tank on all pumps with a built-in pressure switch (unless the manufacturers advise otherwise).
  3. Avoid damage due to grit and dirt by using an appropriate filter.
  4. Pumps make noise: take this into consideration when locating your pump.

Water Consumption Table

ApplicationConsumption
Shower 15 litres per minute
Fill Bath 130 litres
Flush Toilet 4.5 to 14 litres
Lawn Sprinkler 800 litres/hour
Cattle 45 to 90 litres/day
Milking Cows 135 to 180 litres/day
Sheep & Pigs 4.5 to 9 litres/day

Pipe Friction Losses - Steel Pipe

in feet per 100 feet of pipe or metres per 100 metres of pipe.

Friction loss can be in any units per 100 units of pipe. Allowance has been made for the normal number of pipe fittings.

Ltrs.
/Min
½"¾"1"1 ¼"1 ½"2"2 ½"3"
9 12 3.8 1 - - - - -
18 40 10 3 1 - - - -
27 79 20 6 2 0.9 - - -
36 - 35.5 10.7 3.1 1.4 - - -
45 - 53 16.2 4.5 2 0.6 - -
55 - 75 23.5 6.1 2.7 0.8 0.4 -
68 - - 34.8 9.2 4 1.2 0.5 -
82 - - 48 12.5 5.5 1.9 0.7 -
90 - - 59.2 15.5 7 2.4 0.8 -
114 - - 89 23 10.5 3.6 1.4 0.4
136 - - - 34 15.8 5.3 1.7 0.7
159 - - - 45 21 7.2 2.3 0.9
182 - - - 57 27 9.2 3.2 1.2
205 - - - 70 33 11 4.1 1.5
227 - - - 85 39.8 14 4.6 1.9
250 - - - - 48 16 5.9 2.2
273 - - - - 56.5 19.5 6.8 2.6
295 - - - - 65 22.8 7.7 3
318 - - - - 75 26 9 3.4
341 - - - - 85 30 10.3 3.8
364 - - - - 95.7 33.5 11.5 4.4
386 - - - - - 37.2 13 4.9
409 - - - - - 42 14.5 5.5
432 - - - - - 46 16.2 6.1
455 - - - - - 46.8 17.8 6.8
500 - - - - - 60 21 8
546 - - - - - 71.5 24 9.3
591 - - - - - 83.8 28 11
636 - - - - - 95 32 12.4
682 - - - - - - 37 14.2

Pipe Friction Losses - Poly Pipe

in feet per 100 feet of pipe or metres per 100 metres of pipe.

Friction loss can be in any units per 100 units of pipe. Allowance has been made for the normal number of pipe fittings.

- English Size Inside (Diameter) -
- ½" ¾" 1" 1 ¼" 1 ½" 2" 1 ½" 2" 2 ½" 3"
- Metric Size Outside -
Ltrs.
/Min
162532405063PVC Pipe Class B
11 25 3 1 - - - - - - -
23 90 12 3 1 0.5 - 0.4 - - -
45 - 40 10 4 1.5 0.3 1.2 0.5 - -
68 - 80 20 8 3 0.7 2.1 0.6 0.2 -
90 - - 30 13 5 1.3 3.2 1 0.4 0.2
114 - - 50 20 8 2 4.2 1.6 0.6 0.3
136 - - 60 25 10 3 6 2.1 0.8 0.4
159 - - - 30 14 4 8 2.8 1 0.5
182 - - - 40 18 5 10 3.8 1.2 0.7
227 - - - 60 27 7 20 5.2 1.7 1
273 - - - - 38 9 22 7.4 2.5 1.3
318 - - - - 50 12 25 9.5 3.3 1.7
364 - - - - - 16 31 13 4.2 2
409 - - - - - 20 40 20 5.1 2.2
455 - - - - - 24 48 22 6.4 3
546 - - - - - 34 62 26 8.4 3.9
636 - - - - - 46 81 33 12 5.1
727 - - - - - - - 40 15 7
818 - - - - - - - 50 25 9
910 - - - - - - - 60 27 10

We install solar systems in Northern NSW and Southern QLD.


QLD:
Gold Coast (from Coolangatta to Southport), Nerang and Hinterland (Beaudesert) and out West (Warwick, Stanthorpe, Killarney)


NSW:
Northern NSW (Tweed Heads to Yamba, including Evans Head, Byron Bay and Ballina); the Far North Coast Hinterland (Grafton via Lismore to Murwillumbah) and out West (Casino to Tenterfield, including Drake and Tabulam, as well as Woodenbong and Bonalbo)

For larger system we also go up to Brisbane or down to Coffs Harbour and even Glen Innes. Other places by arrangement.