CALCULATION OF NET POSITIVE SUCTION HEAD TECHNICAL

CALCULATION OF NET POSITIVE SUCTION HEAD



 hsv : Net Positive Suction Head [m]
 Pa : Pressure of suction Water level (Absolute pressure) [kg/㎡]
 Hs : Suction Head [m] in case of suction (-),and in case of inlet pressure (+)
 Hl : Suction Loss Head [m]
 Pvp : Vapor Pressure at the water temperature [kg/㎡]
 r : Fluid weight of unit volume [kg/㎣]

For example :

① Wter temperture25℃, suction head-6m When loss in the suction pipe is ignored,

Pa = 10,330kg/㎡, Pvp = 323kg/㎡
Hi = 0, γ= 1000kg/㎥
hsv = 10.33-6-0.323 = 4.01m

② in case that water temperture is 60℃

γ= 983kg/㎥, Pvp = 2031kg/㎡
hsv = 10.52-6-2.07 = 2.45m

③ Hs = 4m inlet pressure, water temperture 100℃

γ= 958kg/㎥, Pvp = 10,330kg/㎡
hsv = 10.78+4-10.78 = 2.45m