CENTRIFU GAL
PUMP TER MS
ABSOLUTE PR ESSUR E
VACUUM
SPECIF IC GR AVITY
PRESSURE AND LIQUID HE IGH T
RELATION SHIP S(H EAD)
VAPOUR PRESSURE
SUCTION HEAD
SUCTION LIFT
TOTAL DYNAMIC HE AD
ABSO LUTE
PRESSURE
Absolute Pressure is the sum of the
available atmospheric pressure and
the gage pressure in the pumping
system
Absolute Pressure(PSIA) = Gauge
Pressure + Atmospheric Pressure
ATM OSP HERI C
PRES SURE
VAC UUM
The ful l or part ial
el imi nation of Atmospheric
Pressure
Atmospheri c Pre ssu re on
the Moon = 0 = Ful l V ac uum
1 Inch Hg Vacuum = 1. 13 Ft
of Water
SPECI FIC GRAVI TY
The ratio of the weigh t of
anythi ng to the wei ght of
water.
Exampl e Speci fic G ravi ty of
HCl = Wei ght of HCl ( /)
Weight of Wate r = 10. 0 (/)
8. 34 = 1. 2
SPECI FIC GRA VIT Y
PRES SUR E AN D LIQ UID
HEI GHT RELATI PON
SH IPS (HEAD)
1 PSI = 2.31 Ft of Water
Pressure, Liquid Height and
Specific Gravity Relationship
Gravity(SG) / 2.31
Pressure(PSI) = Head(FT) x
Specific
VAPO UR PRES SURE
The pressure pushing
agai nst atmospheric
pressure on l iqui ds at
el evated te mperat ures .
SUCTION HEAD
A Suction Head exists when the
liquid is taken from an open to
atmosphere tank where the liquid
level is above the centerline of the
pump suction, commonly known as a
Flooded Suction.
HEAD
FLOODED SUCTION HEAD
SUCTION LIFT
A Suction Lift exists when the liquid
is taken from an open to atmosphere
tank where the liquid level is below
the centerline of the pump suction
SUCTION LIFT
TOTAL DYNAMIC HEAD
Total Dynamic Head (TDH) =
Elevation(ft)
+
Friction(ft)
TOTAL DYNAMIC HEAD
Classification of pumps
Reciprocating
Centrifugal
Single acting
Double acting
Single cylinder
Double cylinder
Triple cylinder
Type of casing
Type of impellor
Working head
Direction of flow
Volute
Vortex
Diffuser ring
Closed
Semi closed Opened
low
medium
high
Axial
Radial mixed
Problems
Pump does not deliver
Pump deliver at reduced capacity
Delive