Piping Stress Handbook Second Edition PDF

Preview

Summary

Piping Stress Handbook Second Edition - - Victor Helguero M. Piping Stress Handbook Second Edition Gulf Publishing Company Book Division Houston, London, Paris, Tokyo Piping Second Library of ISBN G87201_?03-6 Copyright @ 19_86 by Gulf publishing Company, Housron, Texas. All ngfts reserved. printed ...

Description

Piping Stress Handbook Second Edition

-

-

Victor Helguero M.

Piping Stress Handbook Second Edition

Gulf Publishing Company Book Division Houston, London, Paris, Tokyo

Piping Second Library of

ISBN G87201_?03-6

Copyright @ 19_86 by Gulf publishing Company, Housron, Texas. All ngfts reserved. printed in the United Stabs;f

p-ar,b

ttrepf.

A;dca- itis book;; *itt out perJsio'i

may not be regoduced io a"y fo.rn

of the publisher.

$BN GE720r-nB{

.

.::

-i.j.

. -- ,,

Contents vlll

Preface

Chapter

1

Basic Theory of Pipe Stress and ANSI/ASME Codes 831.1, 831.3' ... . .. 1 831.4, and 831.8 Ptpe Stress Compliances . . . .

.

Pipe Stress Theory. Expansion Stresses. Cold Springing. ANSI 831.1 Fower Piping Code Stress Compliances (1983). ANSI 831.3 Chemical Plant and Petroleum Refinery Piping Code Stress Compliances (1984). ANSI B31.4 Liquid Fetroleum Transportation Piping Code Stress Compliances. DOT/B31.8 Gas Transmission and Distribution Piping Systems Stress Compliances. Standard Oudine for ANSI B3l Codes.

Chapter 2 Coefficients of Thermal

Expansion

,........17

Tables. Example Problem.

Chapter 3 Allowable Stress Range for ANSI/ASME Power Piping Code 831.1 ..... 38 (1e83)

.

Tables.

Chapter 4 Allowable Stress Range for ANSI/ASME Petroleum Piping Code 831.3 (19M) . Thbles.

.

... ....73

Chapter 5 Stress Intensification and Flexibility Factors

tlz

Definitions. Thbles.

Chapter 6 Rotational Nozzle Flexibilities for Cylindrical Vessels

.

......l?a

Thbles.

Chapter 7 hessure and Shess Ratioo

.

.......177

Thbles. Instructions and Examples. Branch Reinforcement. Sample Calcula_ tions for Branch Reinforcement.

Chapter 8 Ihsign Criteria for Allowable loads, Moment, and Stresses

........257

Design Criteria for Pumps with Steel Nozzles anit Casings. Design Criteria for Pumps with Cast Iron or Aluminum Nozzles and Casings. Design Criteria ior Tirbine Drivers wilh Steel Nozzles and Casings. Design Criteria for Thrbine Drivers with Cast Iron or Aluminum Nozdes and Casings. Design Criteria for Compressors with Steel Nozzles and Casings. Design Criteria for Cornpres_ sors with Cast Iron or Aluminum Nozzles and Casings. ApI Code 661 Design Criteria for Air-Cooled Heat Exchansers.

Chapter 9 Simptified Solutions for Pipe Stress

265

Example Problem 9-1. Thbles. Example Problem 9-2.

Chapter 10

PropertiesofPipe Definitions. Thbles.

.........292

Chapter

11

Components

Weight and Dimensions of Pipe and

..

. 299

Weight of Pipe and Components. Tables.

Chapter 12 Allowable Pipe Span Formulas and

Thbles

...... ... 314

Pipe-Span Stress Limits. Pipe-Span Deflection Limits. Piping Wind Loads.

Chapter 13 Pipe Support Selection and

Design

..,...,

.

34

Pipe Supports. Spring Supports. Insulated Pipe Supports and Anchors for Cryogenic Service. Thbles.

Chapter 14 Fundamentalsof

ExpansionJoints.

........351

Types of Joint Movements. Nomenclature and Symbols. Types of Expansion Joints. Anchors, Guides, and Supports. Forces and Moments' Cold Springing of Expansion Joints. Cycle Life Expectancy. Corrosion. Erosion. Calculating Thermal Expansion. Precompression. Application, Pipe Guides and Guiding. Iocation of Expansion Joints. End Connections. Covers. Sleeves.

..... ....

Glossary Index

.

368

.,..373

vtl

heface

Determining piping stresses for the design

of

petro_

. chemical and.power plant piping systems iniolves ^many

complex mathematical calculations. These calculationi cal be solved with the aid of any one of several computer programs available provided they have the required ca_ pacity and an acceptable input/output format. The most formidable task facing the engineer is compiling the ex_ tenslve amount ot data needed to run the program. These data include physical properties. allowable stiesses, valve

weights and dimensions. stress intensification factorsthermal expansion coefficients. spring hangers and expanslon Jotnt selectlon, and piping wind loads.

This reference book provides formulas, technical data. and other pertinent design information not readilv avail_ able in a single source for the piping stress analyit in the petrochemical industry who often has difficulry co ecting the required data and solutions to complete a piping stresi

analysis. .Depending on the magnirude and complexity of the job, the data needed to complete a given tasi may be scattered throughout a host of sources. The author's aim is to bring together in a single reference all the above mate_ rial and present it in a convenient form. Much of the information included in this book was ob_ tained from the work of others; some was used in its orisi_ nal form. while some was rearranged for this applicatio-n.

The author wishes to acknowledge his indebtedness to

Mr. Robert Kingshill, Virender Shukla, and Timothv W. Calk. for their assisrance in preparing this handbooki and the American Society of Mechanical Ensineers which generously permitted the author to use sevlral eouations to develop tabulations contained in this handbook. Suggestions and criticism concerning errors that may .9.T]l spite_of all precautions will be greatly appri ciated. They will contribute to the further improvement of

this reference handbook.

Victor Helguero M. , PE.

viii

Basic Theory of Pipe Stress and ANSI/ASME Codes 831..1, 831.3, 83L.4, and 831.8 Pipe Stress Compliances

The bending stress due to temperature, weight of pipe, contents, insulation, snow and ice, wind or earthquake is calculated by the following equatron:

Pipe Stress Theory To understand the basic criteria of the ANSI+ pressure piping code, it will be useful to explain the way different stresses develop when a piping element is subjected to a

number of loading conditions. There are four main

piping element, as shown in Figure l1. The following gives the intensity of these stresses and the manner in which they may be combined: stresses that

affe.t

t,

: Vqgrr'lt*+l Z

a

where

: :

S5

Ii L

* For reasons of space these codes will be designated ANSI codes riroughout the text of the book, Some readers may be mor€ familiar with the desisnation ANSI/ASME as indicated in the headings.

=

Mi M" Z

: : :

Bending stress

In-plane stress intensification factor Out-of-plane stress intensif ication factor In-plane moment, lb-in. Out-of-plane moment, lb-in. Section modulus of pipe, in.3

The direct longitudinal stress due to t€mperature and weisht is calculated as follows:

lJ\J"

.

: Fu :

where A s

t \o S, I

The longitudinal stress due to internal pressure is calculated as follows:

^PD

"P Sr

=

= S, = Ss = Sc

Longitudinal stress and the sum of three component parts (see Equation 1-1). Circumlerential stress Radial stress Shear stless

Figure 1-1. Stress-free-body diagram.

Metal pipe cross-sectional area, in.z Direct force, lb

4t'

where P D

= =

:

Internal pressure Outside diameter of pipe (see Chapter 10)

Pipe wall thickness (see Chapter 10)

S:

:

0 (shear)

2

Piping Stress Handbook

Both significant stresses act in the same direction; therefore the stresses are "additive," i.e.

: S6+\+Sa

S1

(1-l)

Nofe: Inngitudinal stresses due to temperature are excluded from the combination when doing code calculations.

Circumferential stress, S., is primarily due to internal

The preceding method is known as the maximum shear theory (Iresca) and is the preferred method of the ANSI Code. A second method, known as the distortion-energy theory (Von Mises), also provides good results but is not used by the Code:

"'3S-+J--T-+ STTT$"

pressufe:

S^:.q,D -2t Radial.stress, S., is primarily due to internal pressue, which is equal to P.

S.=P

The ANSI pressure piping code recognizes that stress

Shear sfiess, S", is the sum of two component parts: tortional stress and direct shear stress (the second stress is usually negligible). (This condition occurs in three-dimensional piping systems.)

ss: where

Expansion Stresses

T

+2.0&

n

A

SS:

T: F,:

Shear stress Torque, lb-in. Resultant shear force Cross-sectional area of pipe Section modulus of pipe

z: sr: T/22, tortional

due to thermal expansion tends to diminish with time as a

result of local yielding or creep. This reduction of stress will appear as a stress of opposite sign in the cold condition. This phenomenon is known as self springing. Cold springing is similar, and although the hot stresses tend to diminish with time, the sum of the hot and cold stresses for any one cycle will remain practically constant.. This sum is called the stress range, ard, the code for pressure piping defines this allowable expansion stress range established for thermal expansion in terms of hot and cold tabu-

lar S values

S.

stress

:

F (1.25 S"

where S,

While the ANSI pressure piping code considers stresses due to therrnal expansion separately from primary stresses due to pressure, weight, and external loadi_ngs,/it is obvious that when combined stresses formulas and a specific yield criterion existr/stresses from all loadings should be included to delermine the principal stresses before confirming them. Resultant principal stresses at the outside

as:

=

: Sr, : F: S"

+ 0.25 Sh)

Allowable expansion stress range

(see

Chapters 3 and 4)

Allowable stress for the cold condition (see Chapters 3 and 4) Allowable stress for the hot condition (see Chapters 3 and 4) Stress range reduction factor for the cyclic

condition

fiber are as follows:

Sr

. sz

=

:

l/2

|2

Ib calculate

[Sr

+ S. +..//4St+ (S'=TFf

[g + s"

- "v4trTre-.l]zr

the principal stresses use 51 or 52, whichever

is greater, or the following equation:

\4* + C;=TJ'

(r-2)

Tbtal No. of Cycles Over Expected Life 7,000 and less

1.0

14,000 and 22,000 and 45,000 and 100,000 and 250,000 and

0.9 0.8 o.7 0.6 0.5

less less less less less

Basic Theory of Pipe Stress and ANSI/ASME Codes The stress due to thermal expansion, which must not :rceed the allowable expansion range , is callel expansion .;-ess and is defined by the piping code as:

n,:(1 -znci(fJn &=cR

s"={SJ'?+4-(sF xe Equation 1-2, where Sp

:

0 and Sr

:

Ss

The piping code further states that the sum of the long; ,-idinal stresses due to pressure, weight, and other sus:ined external loadings shall not exceed $,. Ifthe longitu:jnal stress due to sustained loadings is less than S1, the

:ode permits the unused portion to be applied to extend range available for expansion effects. There-

-.1e stress

:ore, the code, in effect, permits a total equal to 1.25 S. * Sr,), for thermal expansion stress combined with suesses

from other sustained loadings.

n=[r-tn"El* ' I s" Er,l

These relationships apply only to two-anchor piping systems with no intermediate restraints (use whichever equation is greater) and with the further condition that

sn*E

Flgure 2-1. Curve for determination of average skirt temperature.

30

32

3ll

:

Allowable Stress Range for ANSI/ASME Power Piping Code 831.1 (198t

This chapter contains allowable thermal stresses for petroleum piping. Values of Sh taken from ANSI/ASME Code 831.3-1980, Appendix A, Thble l. (Used courtesv of the American Society of Mechanical Engineers.)

39

Allowable Stress Range tor ANSUASME Power Piplng Code

cooooooooooooogg9000c

oooooooo666o-e?e9i9:?

ddddddddeisidHcsBBEBB ooooooooooouauY::--4E6o5oooa-

I

;;;;;;;;;;-.cq-cocoac

--;;-F

I

c'oooo(rooooooo9P99' ooooooooooc:oooY'i9o o o

o o

o o

o e cr o

o o

o o

o o

o o o cr o o a c{

;-"..'ljj o o 6 o 6 -

9 cJ !? 9 :9

o P E' o

:o

o

o

RRRS S S RRRRR

niNarNNr!Nr\la

o R

oo9 ooo 99oooo ooooooooo 6 6 6 o o o o o ci;. - o o - o o o I o rv.v.\r.v'l|4,1 oo oo ooo

Ln lJl co 'rt OFtT o'|o€o o r\l

'./1 Ufr-F @o O ir 6 ooor

tlFruF -i!.o(} nr,v r'\r av oooo

ro.6^t |,ros:t ,n|'tii oooo

OUrrO F-lrro rtvrJ|F oo30

r.r

tSOO -rv o Fotr 00c-

f\.\t -it rv6 o.o rut/rn co oc

r.ar.v !n

50

,,ttnc> 3

-FlnO av.u{rl

o.\tot Oii 'oO Srrf!rr oooc

!-o('t Orr.O6 oFFt oooo

tlSruF raSo|t|rurvra oooo

:t Itr.\t mollto |.r'|iS oooo

(ttl'lrvo'.rr-a! il^r^F ooao

oi,too o|,|moo F.oo r oeo-

iois |.r.rt-3 .tFoo -d--

O -!no o [email protected] ltlr.\l'.3 oooo

tooa\t3 Fr.lF o :'r^rrr oooo

ol,lor.| 6r,|O.tr r.l oooo

oo|\r0r .o o r.r.ar tlrrt$ it oooo

lnl.tloo oo

FavFtt Oirt,lO Foo -

(> o.v.v rrrr.rl6 iFo6

lF-rn

t rrnttrF

r\|@ tn .vavr4 Ir

ortoo F3Flrtrr/r€

cJ-.o ---Nr'roc!

oitrJto -Uta>tn Nl|r\rl.| oooo

Fav.o o Oo.^F nii3 oooo

r\l@!nur i:[email protected] L,nutrrtr\ oooo

|.1orN FiOC l\€(} jrv o90

orrtF|.ou\ru .vru ta 3 oooo

l/no3 \o c)mo-l.ltfr o oooo

r-'3FJ -ut-!n FF@c> oooo

l\t l\|

N..|-\o l,|o tl6 orn oooo

|a.'rrnrU (>r^Ativ :r FoF ,V..|a\r€ FFO'

rrto.ro -arrrr -un r!rvrntr oooo

orv.o.o .orvlnrt hJt ooo..VF o.ama\J (>o-.n o---

F-Fo oo|no o@

.\lF1l --nr

-F-o53(> 3O oooo--

l.r.olo or.,t -c' aVrur't! soo.'

ootra O3o3F-o|ooo-

Fro o-rt{O r't --.rl

O.,l F F Fro-nF -OtrV ornott rtFtll oooo

-$:to oFavF (t.oFo oooo

o ft

rn

oo...