The size and strength of the pressure pipe going from the intake tank to the turbine is determined by the volume of water and pressure that will be used. Again, high efficiency pays off in lower cost.
At our demonstration site we can use low cost, lightweight 4" plastic tubing because we have only 60 ft. (18.3 m) of pressure to manage. Four inch pipe gives us plenty of flow capacity for either of our Watermotor models.
Manufacturers' charts will indicate how much water can flow through any size and type of pipe. Trying to exceed the pipe's capacity will result in unacceptable pressure loss through friction. Generally, we use 4" pipes with our Watermotors, or in some cases 3" pipe with the smaller model 90.
The pressure pipe is always laid out as straight as possible to avoid unnecessary friction loss as the water goes around bends in the pipe. We have found that short sections of flexible rubber couples and metal hose clamps are very useful to join pipe sections or to provide angles when needed.
At the bottom of the pressure pipe there is a 4" gate valve, and a pressure gauge. The pressure gauge tells the operator if there is a shortage of water or if a filter needs cleaning.
On reaching the turbine, the manifold separates the water flow from the pressure pipe into four smaller tubes, each going to one of the four jets driving the turbine wheel. This system gives the Watermotor great adaptability because it can be run efficiently on anywhere from one to four jets, and the jets themselves can be of various sizes.
This means that the Watermotor can continue in operation during periods of low water, natural in any small stream, or when others are using the water source.