$5$ A process requires the precise control of the flow of a fluid to a reactor operating at $100$ bar pressure $(\frac{1}{b}ar=100$kPa $).$ The flowrate may need to change to match the required reactor output. The flow should be relatively non$-$pulsating.

$($a$)$ Suggest a suitable pump for this duty. Give reasons for your choice.

$($b$)$ Describe, with the aid of a suitable diagram, the construction and operation of your chosen pump.