=+10-26.

A secondary pump located in the basement of a 20-story building circulates water throughout There is 25 ft (8 m) of lost head in the riser to the twentieth floor. The pump produces 60 6

(18.3 m) of head.

(a) What pressure must be established at the pump suction by the expansion tank to insure a positive pressure in the circuit on the twentieth floor with the system in ope.

ation?