Ross Mackay Forum Moderator 93 Posts
Re: Why is an expander required on the discharge side of a pump?12 July 2010 at 1:29pm
I would suggest the following answers to your questions.
1. The pipe size needs to be increased from the pump discharge to slow down the velocity of the output and thus reduce the friction losses.
2. As the discharge valve is the pump isolating valve for maintenance purposes, when the NRV is located between the pump and the isolating valve, it too can be maintained.
3. An automatic valve cannot always stop reverse flow through the pump.