A water system has a pump that delivers

500(m^(3))/(h)

at a rotational speed of

1200rpm

and 80 percent efficiency. The pump operates at an elevation of

1000m

above sea level (use an atmospheric pressure head of

9.19m

) and the temperature is

20\\\\deg C

. The total dynamic head is

40m

and the pump manufacturer's required net positive suction head is

NPSH_(R)=5

. What is the allowable suction head for the pump? The vapor-pressure head at

20\\\\deg C

is

0.25m

, the entrance loss is

0.0001m

, the bend losses add up to

0.17m

and the sum of head losses due to friction in the suction piping is

1.1m

.

A water system has a pump that delivers 500m3/h at a rotational speed of 1200rpm and 80 percent efficiency. The pump operates at an elevation of 1000m above sea level (use an atmospheric pressure head of 9.19m ) and the temperature is 20C. The total dynamic head is 40m and the pump manufacturer's required net positive suction head is NPSHR=5. What is the allowable suction head for the pump? The vapor-pressure head at 20C is 0.25m, the entrance loss is 0.0001m, the bend losses add up to 0.17m and the sum of head losses due to friction in the suction piping is 1.1m