Implications of this chapter

I think that I have made a case for engineers to regard pressure transients other than slow ones to be virtually unpredictable and therefore best eliminated at the design stage. This raises the question of what methods can be used to deal with applications where it is essential to be able to reduce a flow quickly in, say, a pipe feeding a water turbine.

 

There are three ways to the best of my knowledge. They have one aspect in common. A pressure relief system is fitted close to the machine to separate the short pipe supplying the machine from the long pipe from the reservoir from which the water flows. Then the water from the pressure relief system either goes to a surge tank, to a air pressure vessel or is discharged through some device like a swirling nozzle to dissipate the energy. I will deal with this topic in connection with reciprocating pumps and with turbines but it is appropriate to refer to the basic methods at this point.