Air Vessel Sizing for Water Hammer Prevention in Pipelines

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Air Vessel Sizing for Water Hammer Prevention in Pipelines

Figure 1: Pipeline Prole

Reference: Simple Guide for Design of Air Vessels for Water Hammer Protection ofhttp://www2cemetuedutr/!ce"#$/lin%s/docs/&'"#$(We)*iles/air(cham)erpdf 

http://www2.ce.metu.edu.tr/~ce534/links/docs/CE534-WebFiles/air-chamber.pdfhttp://www2.ce.metu.edu.tr/~ce534/links/docs/CE534-WebFiles/air-chamber.pdf

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Figure 2: Maimum an! minimum "ea! envelopes #ase! on incompressi#le $o% t

Figure ': Air an! Vessel Volumes

 +erms ,n a)o-e charts:

((((((((((((((((((( .0

where:

S1 Dimensionless parameter

g

Static head a)o-e pump discharge no33le plus destination pressure .in head

A

L Length of pipeline4 m

,nitial Pipeline Velocit54 m/s

minimum static head a)o-e pump discharge no33le plus destination pressur

ma6imum static head a)o-e pump discharge no33le plus destination pressu

S7 ,nitial gas -olume in -essel4 m#

gra-itational acceleration4 89 m/s2

Ho 

&ross(sectional area of pipeline4 m2

-7 

Hmin

Hma6

2

0

00'

v L A

 H  g S S 

××××

=

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*or maorit5 air -essel -olume calculations consider the following -alues

and

4.0

0

min = H 

 H 

4.1

0

max=

 H 

 H 

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*rom ;*igurre 2; 4 S1

2$>m

8#

S $8

S with S* $8

277m

$?"m

Air -essel -olume4 m#

Sw  ,nitial water -olume in -essel4 m#

.Hmin

 / H7 7$0

Hmin

 / H7 

H7 

dp 

-7 

Safet5 factoron VesselVolume.L/D0

-essel 

m2

S7 m#

hmin

Sw  m#

m#

m#

D-essel

L-essel

,

      @    u      t      l    e      t

Air Vessel

&ompressed Air or itrogen

      d      7

Li=uid

0

2

0

0

 H  g 

v L AS 

×

××

=

wS S S    += 0

min

2

0

h g 

v L AS w

×

××=

min0min  H  H h   −=

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2 Si3e needs to )e -eriBed )ased on point num)er to ensure that -elocit5 is %ept at or )e

)nlet (onnection

(((((((((((.>0

where:

,nlet connection si3e4 mm

pipeline si3e4 mm

*utlet (onnection +!o,

do is generall5 72" to 7" times the pipe diameter d

p

di 

dp 

Pipeline

2

14/1

max

2

0 ×   

×=

h g 

v

d 

d 

 p

i

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((((((((((((.?0

04 we get

(alculations +)nlet - *utlet Size,Inputs

877 mm

$ m/s

$7m

Outputs

22" mm

98inch

98mm

$?inch

Selecte! Size

7 inch

> inch

Prepared )5: An%ur Sri-asta-a

&hemical 'ngineer

Since Hma6

$CH74

dp 

-7 

H7 

do 

di 

do 

di 

an%ur27>Ehotmailcom

0maxmax  H  H h   −=

0max  4.0   H h   ×=

2

1

4.0

4/1

0

2

0 ×   

××=

 H  g 

v

d 

d 

 p

i

mailto:ankur_2061@hotmail.commailto:ankur_2061@hotmail.com

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  umping Lines

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eor&

terms04 m

e .in head terms04 m

re .in head terms04 m

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let

di

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low 7 m/s in the outlet piping

dp

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