Fire pump

We have connected our fire pump (electric) to a static water storage tank (Positive)with in 2 mts away. The diameter of suction and delivery pipes are same (dia 150mm). Please confirm whether we have to increase the suction diameter to one size at least more than the delivery size.

What will happen if both the pipe sizes remain same. The discharge pipe is travelling more than 150 mts from pump connecting to various external and internal hydrants. The maximum elevation of pipe from pump is minimum 20 mts.

Please confirm.