PowerSpout
TRG installation 2018
Last revised July 2018
© 2018 EcoInnovation Ltd (NZ)
Page 13
2.1.3.
Pressure Gauge
Supplied with turbine.
Thread is 1/4" BSP male.
To be mounted on penstock or the manifold pipework upstream of the valves.
Normally this is done with a saddle, reducing bushes, (and optionally a valve), as shown
below right. (These fittings are not supplied).
Can also be mounted in a hole (drilled and tapped) in pipe or fittings.
Convert the units of pressure:
9.8kPa = 1 metre of head
43 PSI = 100 feet of head
The pressure gauge is absolutely essential for commissioning, troubleshooting and flow
management, so you must install it.
The gauge is slightly affected by temperature changes, so for maximum accuracy you
should vent it by pushing the rubber bung aside with a thumbnail. This allows air to enter or
leave the casing. Or snip off the nipple on the top of the plug, if plug is uppermost.
Measure the static pressure (valves closed) and compare this with the design calculation. If
it is low then check for air trapped in the supply pipeline (called penstock). If it is high then be
ready for more power than expected (for a given size jet). Your circuits and equipment need
to be fit to carry this extra load or you need to use smaller jets.
Measure the dynamic pressure (valves open) and compare this with static pressure to
calculate the pipe efficiency percentage. Does this match the calculation?
If turbine output is low then the pressure gauge helps you find the cause.
Low pressure could mean blocked filter, lack of water flow, or trapped air in the pipe.
Higher than usual running pressure could mean an obstructed jet.
