Project of Pressure Vessel

7/24/2019 Project of Pressure Vessel

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Dept of Mechanical and Marine Engineering, B/ Dar University, Machine Design project. 1

PRESSUR VESSEL DESIGN

1.1 INTRODUCTION

Engineering plastic has been used for pressure vessel application for a long tie.!ressure is closed containers designed to hold gases or li"uids aterial under internal and

e#ternal pressure. !ressure vessels are designed to operate safely at a specific pressure and

teperature technically referred to as the design pressure and teperature.

!ressure vessels ay theoretically be alost any shapes ade of section spheres and

cones are usually eployed. $ coon design is a cylindrical %ith heispherical ends caps or

heads.

&hen the vessels %alls is thin, the stresses distribution throughout its thic'ness %ill not

vary significantly and so %e %ill assue that its unifor or constant.

(he design rule in the codes and liited to vessels of cylindrical or spherical and ellipsoidal

shapes under internal or e#ternal pressure and to head and no))les attachent for such vessels

rules for ore coplicated types of construction and for loading other than that due to pressure

are beyond the scope of the codes to include such rule %ould turn the code in to design hand

boo' and it %ould restrict the designer in %or'ing out his design in accordance %ith acceptable

engineering principles. (he code receives that the shell provided details of construction that %ill

be as safe as those provided by the rules of the code. *oe proble of designers of ellipsoidal

pressure vessels that have their a#is vertical and subjected to applied forces in addition to

internal and e#ternal pressure the vertical forces considered are the %eight of any attachents

to vessels.

+inally, pressure vessel are refers to those reservoirs and apparatus %hich %or' under

internal and e#ternal pressure and operate under the pressure.

Machine Design !roject !repared By $leu (eshoe !age 1


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1.2 Classification of pressure vessels

!ressure vessels can be classified in different categories as follo%s-

1.2.1. According to the dimension

(he pressure vessels according to their diensions ay be classified as thin shell or thic'

shell the ratio of e"ual thic'ness t0 of the shell to its diaeters D0 deciding factor.

a0 (hin shell- if the ratio ofD

t

is less than10

1

is called a thin shells.

b0 (hic' shell- if the ratio ofD

t

is e"ual or greater than10

1

is called thic' shell used in

high pressure cylinders, gun, barrels and other e"uipents %here as thin shell are

used in boiler, tan's and pipes. 1.2.2. According to the end construction(his can be classified in to t%o groups-a) pen end construction pressure vessels

b) 2losed end construction pressure vessels1.2.. According to the geo!etrica" sha#es

a0 2ylindrical geoetrical shapes

b0 2onical and

c0 *pherical vessel %ith one or t%o cones.

1.2.$. According to the #osition arrange!ent

a0 3ori)ontal pressure vessel

b0 4ertical pressure vessel

c0 *pherical pressure vessel

1.2.%. According to the !ateria"s

(he pressure vessels are according the aterial classified as-

a) Brittle aterial pressures vesselsb) Ductile aterial pressure vessels

1.2.&. According to the direction o' 'orce acting on the (a"" o' esse"s.

a0 *ubjected to internal pressure

( )pi

b0 *ubjected to e#ternal pressure

( )p



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1. component of pressure vessels

(here are four coponents of pressure vessels this are-

$. headB. shell2. no))le andD. support

$. 3E$D$ll pressure vessel shells ust be closed at the ends by heads or another shell section0.

3eads are typically curved rather than flat. 2urved configurations are stronger and allo% theheads to be thinner, lighter, and less e#pensive than flat heads. 3eads can also be used inside a

vessel. 3ead are usually categori)ed by their shapes. Ellipsoidal, heispherical, torispherical,conical, toriconical and flat are the coon types of heads.

B. *3E66

(he shell is the priary coponent that contains the pressure. !ressure vessel shells are%elded together to for a structure that has a coon rotational a#is. Most pressure vessel

shells are cylindrical, spherical, or conical in shape. 3ori)ontal drus have cylindrical shells and

are fabricated in a %ide range of diaeters and lengths.

2. 7886E

$ no))le is a cylindrical coponent that penetrates the shell or heads of a pressure 4essel.

(he no))le ends are usually flanged to allo% for the necessary connections and to perit easy

disassebly for aintenance or access. 7o))les are used for the follo%ing applications-

$ttach piping for flo% into or out of the vessel.

$ttach instruent connections, e.g., level gauges, thero %ells, or pressuregauges0.

!rovide access to the vessel interior at an %ays.

!rovide for direct attachent of other e"uipent ites, e.g., a heat e#changer

or i#er0D. *U!!9(

(he type of support that is used depends priarily on the si)e and orientation of the

pressure vessel. n all cases, the pressure vessel support ust be ade"uate for the applied

%eight, %ind, and earth"ua'e loads :;


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so that radial theral e#pansion of the shell does not cause high theral stresses at its junction%ith the s'irt

ii. Leg su##ort*all vertical drus are typically supported on legs that are %elded to the lo%er portion

of the shell. (he a#iu ratio of support leg length to dru diaeter is typically 5-1. (henuber of legs needed depends on the dru si)e and the loads to be carried. *upport legs are

also typically used for spherical pressuri)ed storage vessels. (he support legs for sall verticaldrus and spherical pressuri)ed *torage vessels ay be ade fro structural steel coluns orpipe sections, %hichever provides a ore efficient design.

iii. Sadd"e su##ort 3ori)ontal drus are typically supported at t%o locations by saddle supports. $ saddle*upport spreads the %eight load over a large area of the shell to prevent an e#cessive local stressin the shell at the support points. (he %idth of the saddle, aong other design details, isdeterined by the specific si)e and design conditions of the pressure vessel. ne saddle supportis norally fi#ed or anchored to its foundation.

i. Lug su##ort6ugs that are %elded to the pressure vessel shell, %hich are sho%n on, ay also be used to

support vertical pressure vessels. (he use of lugs is typically liited to vessels of sall toediu diaeter 1 to 1= ft.0 and oderate heighttodiaeter ratios in the range of 5-1 to >-1.6ug supports are often used for vessels of this si)e that are located above grade %ithin structuralsteel. (he lugs are typically bolted to hori)ontal structural ebers to provide stability againstoverturning loads? ho%ever, the bolt holes are often slotted to perit free radial therale#pansion of the dru.

Machine Design !roject !repared By $leu (eshoe !age @


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1.@. bjective of the design

1.$.1. +ain ob,ectie

(he ain objective of y project is to design a vertical pressure vessels position %ith ellipsoidal

head by estiating the internal pressure and teperature on its effect and having a aterial of

lo% alloy steel and use ediu of aonia at the teperature of

15

and pressure

Mpa45

.

1.$.2. S#eci'ic ob,ectie

*pecifically, %ould li'e to design support, head, shell and no))le and its has its o%n procedures

to design each coponent and to design the hole assebled of pressure vessels.

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2. !eneral Design procedures

Design#ressure

$ vessel ust be designed to %ithstand the a#iu pressure to %hich it is li'ely to be*ubjected in operation. +or vessels under internal pressure, the design pressure is norally ta'en as the pressure

$t %hich the relief device is set. (his %ill norally be > to 1= per cent above the noral&or'ing pressure, to avoid spurious operation during inor process upsets. &hen deciding(he design pressure.

100

10+= ooD ppp

10

14545 +=Dp

5.49=

7/

2

Design te!#erature

(he strength of etals decreases %ith increasing teperature so the a#iu allo%abledesign stress %ill depend on the aterial teperature. (he design teperature at %hich thedesign stress is evaluated should be ta'en as the a#iu %or'ing teperature of the aterial,

%ith due allo%ance for any uncertainty involved in predicting vessel %all teperatures.

(hen

CT O150 =

+ro typical design stress table find the stress for lo% alloy steel-

Design stress-

240=D

7/

2

(ensile strength-

550=t

7/

2

2.1. Design o' she""

+or cylindrical shell thic'ness re"uired to resist internal pressure can be deterined fro

the forula. 7o% assue outer diaeter of the shell is

M1

. (hen chec' for %hich option thatour pressure is safe.

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f

)2......(....................4.0

.........................385.0

)1......(....................1

.........................385.03

D

DD

oD

pSE

RptuseSEp

z

zRtuseSEp

+=

&here * allo%able stress Design stress0

E joint factor

*ince

22

22

/4.92/5.49

/240385.0/5.49

mmNmmN

mmNmmN


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(hen,

mmL

mm

DL

4000

10004

4

=

=

=

L

Fig 2.1.1 cylindrical shell

;0. (o calculate the volue of the shell

(

( ) ( )( )

3

22

22

10014.1

4

48061000

806

)97(21000

24

mV

V

mmDi

tDoDibutLDD

V io

=

=

==

=

=

2.2. Design o' -ead

$ll pressure vessel shell ust be closed at the end by heads. (he ends of cylindrical

vessel are closed by head various shapes. (his are-

+lat plates head

3eispherical head

Ellipsoidal head etc

But y design head is ellipsoidal head.

Most standard ellipsoidal are anufactured %ith a ajor and inor a#is ratio of1:2

the

follo%ing e"uation can be calculated re"uired thic'ness.

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10 (o calculate thic'ness

mmmmt

mmNmmN

mmmmN

t

PSE

RPt

D

D

8797.86

)/5.49(9.0/240

500/5.49

9.0

22

2

=

+

=

+=

h

D &here4

oDh=

+ig 5.5.1. Ellipsoidal head

50 (o calculate ellipsoidal head volue

3

2

2

131.0

6

25.0)1(

6

mV

mm

hDV

h

Oh

=

=

=

a"cu"ate the stress on the she"" using "a!e/s e0uationangentia" stress 3is the a#iu tensile stress and it is 'no%n as

circuferential stress.

Radia" stress- is the a#iu copressive stress and it is negative. (he

negative sign indicates that the radial stress is opposite to design stress e"ual.

*ince, if the stress is less than the a#iu tensile strength of the aterial, then thedesign is safe. 7o% to calculate the value of stress.

a0 (angential stress

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TensiemmN

mm

mm

mmmm

mmmmN

R

R

RR

RP

t

i

O

iO

iDt

........./06.233

)403(

)500(1

)403()500(

)403(/5.49

1

2

2

2

22

22

2

2

22

2

=

+

=

+

=

b0 9adial stress

ecompressi!mmN

mm

mm

mmmm

mmmmN

R

R

RR

RP

r

i

O

iO

iDr

............./5.49

)403(

)500(1

)403()500(

)403(/5.49

1

2

2

2

22

22

2

2

22

2

=

=

=

c0 6ongitudinal stress

( ) ( )2

22

22

22

2

/78.91

8061000

)806(/5.49

mmN

mmmm

mmmmN

DD

DP

L

iO

iDL

=

=

=

2.. Design of No""le(he forula that a going to calculate is the sae as thic'ness forula to calculate for

shell, the only difference is the diaeter %e use.

mmD"t i 300=

1=E

( )mm

mmNMPa

mmmmN

PSE

RPt

D

iD

58.28

/5.494.01240

150/5.49

4.0

2

2

=

+

=

+

=

Length of nozzle

ML

mmLkkwherekD

L

2.1

300464

=

=


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mm

mmmm

DtD i

16.357

30016.57

20

=

+=

+=

3ere no need of volue b/c its function is to as %ay of a fluid.

(he stress developed on no))le.

22

/8.25958.282

300/5.49

2mmN

mm

mmmmN

t

#pc =

=

=

MPaMpatc 5508.259


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=mD

Mean diaeter of vessel

( )mtDi 310+=

m

mmDm

903.0

097.0806.0

=

+=

(hus

( ) mmmm%S 097.0903.08.04903.015.1240 +=

N%S 165.114=

(o find the %eight of fluid %hich score the a#iu %eightF

(he density of aonia fro the table %e see

3/604 mk&=

&!

&m%

ff

f'

=

=

&here

=f!the volue of fluid in the vessel

=f(he a#iu density of aonia

='%

&eight of fluid

3/604 mk&f=

(hus,

N%smmk&m%

'

'

82.7294/81.9/60423114.1

233

==

(o find the total %eight of the syste %ill be

NN

%%% 'S

82.7294165.114 +=

+=

N% 98.7408=

choose round bar as support that is s'irt support is preferable to vertical position. (he three

s'irt support is %elded at

co

120

the cylindrical part of the shell.



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(herefore %eight each support carries

3

tota%

of load.

6et

3

tota

each

%

P% ==

N

N

P 66.24693

98.7408

==

The material selection for skirt support is stainless.

(he length of %eld part #0 is subject to pure shear and the bar %eld at t%o part

oa#eachofwei&htp

stressshearaowabe

thicknesswe#S%here(Sp

ao

ao

=

=

==

707.02

&here

2.3

3

=

=

=

n

saft)offactornn

)

ao

(a'e

t) =

in the standard table

Mpat 540=

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Then diameter of support is.

= 64

2

24

E

NPD e

( )

( )mmD

mmN

mN

65.42

14.3

64

/21000014.3

291.790222

2

=

=

2.#. Design of $olts

Use the follo%ing forula iportant to find the si)e and nuber of bolt.

6et D internal diaeter of cylinder

! pressure in the cylinder

dc core diaeter of the bolt

=tb

!erissible tensile stress of the bolt

n nuber of bolt

3ere %e 'no% that the up%ard face acting on the cylinder cover is-

( )1.........................................4

= D'

(his force is resisted by n nuber of bolt and the resisting force offered by n nuber of bolts is

( )2..................................4

2 n#c' tbR

=

+ro e"uation 10 the up%ard force acting on cylinder cover is

N'' 87.252432305.498064

2 =

=

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+ro e"uation 50 the resisting force by the bolt

n#c' tbR

= 24

3ere select the aterial for the bolt lo% alloy steel. *o,

2/550 mmNtb=

and the core

diaeter is fro the table by ta'ing standard

60M

si)e.

+ro the table

mm#c 177.53=

bots'

n

''Sincen'

n'

RR

R

2167.2077.1220899

87.25243230

77.1220899

77.1220899

550177.534

2

===

==

=

2.6. Design of nut

f the bolt and nut are ade up of siilar aterial then the effective height of the nut adee"ual to the noinal diaeter of the bolt. *ince the bolt diaeter is A=. so the effective

height of the nut is also A=.

2.5. 6"ange design

*tandard flanges %ill be specified for ost applications. *pecial designs %ould beused only if no suitable standard flange %ere available? or for large flanges, such as the bodyflanges of vessels, %here it ay be cheaper to si)e a flange specifically for the duty re"uiredrather than to accept the nearest standard flange, %hich of necessity %ould be oversi)ed.

Machine Design !roject !repared By $leu (eshoe !age 1A

Designation pitch noinal pitch core diaeter depth of stress

Diaeter nut G diaeter bolt nut bolt area

Bolt dD0

2mm

60M

5.5

60

428.56

177.53

046.54

374.3

2360


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*tandard flanges are available in a range of types, si)es and aterials? and areused e#tensively for pipes, no))les and other attachents to pressure vessels.

7o.

si)e

pipe

o.d.

d1

Flange

D b h

Raised face

d4 f

Drilling

d2 k

Boss

d3

1== 11@.; 51= 1A @= 1@ ; 1 1C= 1;=

+igure 5.>.1. (ypical standard flange design $ll diensions 0.

2.7. Design o' Gas*ets

Has'ets are used to a'e a lea'tight joint bet%een t%o surfaces. t is ipractical to

achine flanges to the degree of surface finish that %ould be re"uired to a'e a satisfactoryseal under pressure %ithout a gas'et. Has'ets are ade fro IseiplasticJ aterials?

%hich %ill defor and flo% under load to fill the surface irregularities bet%een the flangefaces, (he follo%ing factors ust be considered %hen selecting a gas'et aterial-1. (he process conditions- pressure, teperature, corrosive nature of the process fluid.5. &hether repeated assebly and disassebly of the joint is re"uired.;. (he types of flange and flange face.

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Based all the above entioned factors considering the operating teperature andcorrosiveness of the process fluid %ill be the controlling factor in gas'et selection. 4egetable

fibre and synthetic rubber gas'ets can be used at teperatures of up to.100 co

Su!!ar8 (his course provided an overvie% of pressure vessel echanical designre"uireents. t suari)ed the ain coponents of pressure vessels.Materials ofconstruction, design re"uireents and considerations, fabrication, inspection andtesting. !articipants no% have a good overall understanding of pressure vesselechanical design re"uireents, are prepared to use this 'no%ledge in their jobs, andhave sufficient prere"uisite inforation to ta'e ore detailed pressure vessel courses.

Ac%no&ledgements +irst of all %ould li'e to than's for y $dvisor $to $bdul ha'i *hu'utea for thathe has given e all the inforation and the procedure, all the data and for he has given

the reference boo's.*econdly %ould li'e to than's y doritory for giving e the chance to tal' %ith

the about y design and %ould than's for

th5

year Mechanical engineering student%onde to give the inforation.

$nd, finally than's for all being %ith e.

RE6ERENE 9::;S

9.K. *innot, 2oulson L 9ichardsons, 2heical Engineering, volue A, (hird

Edition.

!aul Buthod and (ulsa, 'lahoa, pressure vessel handboo', (enth Edition.

Dennis 9. Moss, !ressure 4essel Design Manual, (hird Edition.



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Mr. H. Hhanbari, Mr. Mohaad 9a)a 6a)adi and M. *erai. !ressure 4essel

Design Huides L !rocedures.

Ta$le content

23$!(E9

1.1 ntroduction of pressure vessel101.5 2lassification of pressure vessel.501.; 2oponent of pressure vessel..;0

1.@ bjective of the design.>0

23$!(E9

D'(I!N )ROC'DUR'

5.1 Design of cylindrical shell( )6..........................................



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5.5 Design of ellipsoidal head( )8..............................................

5.; Design of no))le( )10......................................................................

5.@ Design of support

( )11..................................................................

5.> Design of bolt( )13.........................................................................

5.A Design of nut( )15........................................................................

5.C Design of flange( )15......................................................................

5. Design of gas'et( )16......................................................................

5. *uery

( )16....................................................................................

$2K7&6EDHEME7(*

9E+E9E72E

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Project of Pressure Vessel

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