Attachment-1
PROJECT TITLE : Cooling Tower Package Engineering in Halliburton -Multi Chem Batch Plant
DOC. TITLE : NPSH (A) CALCULATION FOR COOLING WATER PUMPS
DOCUMENT NUMBER : A8JE-4-0701-01-00036_Rev-B
(P-504A/B/C)
NPSH (A) CALCULATION FOR COOLING WATER PUMPS (P-504A/B/C)
PUMP DATA
3 m3/hr
Lube oil outlet flow
0.001 m3/sec
Vapor Pressure 0.001 bara 0.0121 m(lc)
LO TANK outlet pipe 1.5 Inch 0.0381 m (STD schedule)
Density 840 kg/m 3
0.84 Specific Gravity
Fluid Viscosity 10.920 cP 0.01092 kg/m.sec
Pipe Roughness of SS Pipe 0.0406 mm 0.0000406 m
Operating pressure 1.0133 bara 12.30 m(lc)
NPSH(A) CALCULATION:
NPSH(A) - Net Positive Suction Head Available -It is the amount of head or pressure that is available to prevent vaporization or cavitations of the fluid in the system.
It is the amount of head available above the vapor pressure of the liquid at a specified temperature, and is measured in m of liquid.
NPSH(A) = hss - hfs - p
NPSH(A) = Net positive suction head available in (m)
hss = Static suction head in (m)
hfs = Suction friction head in (m)
p = Vapor pressure in (m)
A) STATIC SUCTION HEAD (h ss):
hss = Pr. acting on the liquid surface (m) + Elevation diff. between Basin outlet to pump Centerline (m)
= 12.30 + 0.3
Static suction head = 12.596 m(lc)
B) SUCTION FRICTION HEAD LOSS (h fs):
hfs = (f L / D) x (v2 / 2gc)
f = Darcy friction factor
L = Pipe length in m
v = Fluid velocity in m/sec
D = Pipe diameter in m
gc = Dimensional constant in m/sec2 = 9.81 m/sec2
B.1) Fluid velocity (V):
V=Q/A
V = Average velocity of flow in m/sec
Q = Quantity of flow in m3 /sec
A = Area of the pipe in m2
Page 1 of 3
Attachment-1
PROJECT TITLE : Cooling Tower Package Engineering in Halliburton -Multi Chem Batch Plant
DOC. TITLE : NPSH (A) CALCULATION FOR COOLING WATER PUMPS
DOCUMENT NUMBER : A8JE-4-0701-01-00036_Rev-B
(P-504A/B/C)
NPSH (A) CALCULATION FOR COOLING WATER PUMPS (P-504A/B/C)
B.2) Darcy friction factor (f):
1/(f)^0.5 = -2log(Ɛ/3.7D + 2.51/NRe(f)^0.5) Nre>2000. Hence the Flow is turbulent and Friction Factor is calculated from
colebrook correlation equation i.e. 1/(f)^0.5 = -2log(Ɛ/3.7D + 2.51/N Re(f)^0.5).
f = Darcy friction factor
NRe= Reynolds number
Calculation Part:
Dia of pipe, inch Q (m3/sec) D (m) A (m2) V (m/sec) Nre Friction factor f
1.5 0.001 0.0381 0.0011400918281 0.7309 2142.20 0.01466
B.3) Friction head due to pipelength
Dia of suction pipe, Length of the
Head loss m(lc)
inch pipe (m)
1.5 4 #REF!
#REF! 15 #REF!
#REF! 2 #REF!
#REF! 1.2 #REF!
Head loss, m #REF!
B.4) Friction head due to fittings: 16" pipe
Equivalent length, Head loss
Fittings Quantity L/D
Leq m(lc)
Expansion bellow 1 0.01
Reducer 1 20 0.762 0.00798
90 Elbow (1.5D)
o
1 20 0.762 0.00798
Head loss, m 0.02597
B.5) Friction head due to fittings: 12" pipe
Equivalent length, Head loss
Fittings Quantity L/D
Leq m(lc)
Pump inlet nozzle 0 64 #REF! #REF!
Butterfly valve 0 50 #REF! #REF!
Tee (Flow through Side outlet) 0 65 #REF! #REF!
90o Elbow (1.5D) 2 20 #REF! #REF!
Head loss, m #REF!
Page 2 of 3
Attachment-1
PROJECT TITLE : Cooling Tower Package Engineering in Halliburton -Multi Chem Batch Plant
DOC. TITLE : NPSH (A) CALCULATION FOR COOLING WATER PUMPS
DOCUMENT NUMBER : A8JE-4-0701-01-00036_Rev-B
(P-504A/B/C)
NPSH (A) CALCULATION FOR COOLING WATER PUMPS (P-504A/B/C)
B.6) Friction head due to fittings: 18" pipe
Equivalent length, Head loss
Fittings Quantity L/D
Leq m(lc)
Pump inlet nozzle 0 64 #REF! #REF!
Ball valve 0 50 #REF! #REF!
Tee (Flow through Side outlet) 3 65 #REF! #REF!
90o Elbow (1.5D) 0 20 #REF! #REF!
Head loss, m #REF!
B.7) Friction head due to fittings: 12" pipe
Equivalent length, Head loss
Fittings Quantity L/D
Leq m(lc)
Butterfly valve 1 50 #REF! #REF!
Tee (Flow through Side outlet) 0 65 #REF! #REF!
Reducer 1 20 #REF! #REF!
Strainer 1 340 #REF! #REF! L/D Assumed
HEAD LOSS #REF!
B.8) Friction head due to fittings: 10" pipe
Equivalent length, Head loss
Fittings Quantity L/D
Leq m(lc)
Pump inlet nozzle 1 64 #REF! #REF!
90o Elbow (1.5D) 1 20 #REF! #REF!
Head loss, m #REF!
Total Frictional Loss #REF! mlc
Design margin 20% considered for frictional loss #REF! mlc
NPSHA
hss hfs p NPSH(A)
m(lc) m(lc) m(lc) m(lc)
12.596 #REF! 0.012 #REF!
CONCLUSION:
The Available Net Positive Suction Head for the Pump is = #REF! m of Water
SUCTION HEAD = hss - hfs
= 12.596 - #REF!
SUCTION HEAD = #REF! m of liquid
= #REF! m of water
SUCTION PRESSURE = #REF! psia
= #REF! bara
Notes:-
1.NPSH Available should exceed the NPSH Required by the margin recommended in the client standard.
2.Flow velocity for the pump suction line and the calculated pressure drop also within the limit, hence the pump suction line size is found to be adequate.
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