PowerSpout
React Pump Installation
© 2019 EcoInnovation Ltd (NZ) V2.1
Page 84
6. Pipe size selection
PE pipes are the obvious choice for the PowerSpout React pump (and to protect the solar
PV wires) because of the range of available sizes, pressure ratings and lengths and the fact
that they are durable, low cost and commonly available.
6.1. Selecting suitable delivery pipes (from React pump to tank)
Pipe friction (depending on both the flow rate and pipe size) will add to the static pressure
resulting in a higher "dynamic head" at the React pump. Dynamic head is the sum of the
vertical height (static head) and the friction head (due to pipe friction). Your React pump will
self-optimised to produce maximum flow under the conditions it sees as it comes with
electronic maximum power point tracking (MPPT). If more power is available the pump
speed is increased, less power the speed is decreased.
If you get your dynamic head calculations grossly wrong, and you calculate 100m and then
get 160m pressure instead, it is possible that your supply pipe will bust (although there is
some safety factor in the pressure rating). You will have installed 12 Bar pipe when 16 Bar
was required. Such an error will not damage the React pump as it can operate to 300m
head. But pumping flow performance in marginal solar conditions will suffer.
Start by measuring:
the suction lift at your site from water surface up to React pump centre (is it less than
3m?).
the lengths of your suction and delivery pipes.
the height of your header storage tank above the React pump (static head).
Based on the tables provided in this document you will need to select, purchase and install
the correct suction and delivery pipe sizes. Your supplier (and/or Ecoinnovation) will be
happy to help you with this. If in doubt always go up a size to keep your options open for
more future pumping capacity. Pipes will also foul over time with fine sediments and this can
greatly increase the pipe friction head on long pipe runs over time.
Every site is different, so the design process is worth doing, and the measurement of head is
key. However, if you get your site data wrong, the React pump will work just fine so long as
your pipe does not burst.
The difference between internal and outer diameter
6.1.1.
Inside diameter is critical
for calculation of pipe friction
loss since a variation of as little as 1mm can have a very
significant effect on the headloss, which increases the
dynamic head and hence reduces the output flow of the
React pump. Your pipe can rupture if you make a gross
error in pressure calculation.
A given pipe size based on "outer diameter" OD is often
available in a number of pressure ratings and the actual
"inner Diameters" IDs will not be the same. Pipes that
have the same OD but different IDs due to differing wall
thickness are referred to as being in the same NB
(nominal bore) size classification. Bore means inner
diameter but nominal bore is the not the same as actual
ID.
But you need to find out the exact ID of your pipe because this will determine the head loss.