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2B 1BASIC PIPING STRESS CAESAR II

By Piya Kittitanesuan ( )

Lead Piping Engineer

Penspen Limited. (Thailand) (update 29 February 2008)

U (Basic Piping Stress Analysis) (Operating Temperature) (Ambient Temperature) ambient code (Piping Engineer) (pipe support ) line stop, guide nozzle (Equipment)

Allowable Forces Moments Allowable Allowable Load code pump code API 610 steam turbine code NEMA SM23 Tank code API650 code (project) code

(Flexibility) (Fitting) pressure drop

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1.1 UBASIC STRESS QUANTITIES pipe stress

stress

UAXIAL STRESS ()

USHEAR STRESS ()

UBENDING STRESS ()

= M c M I

M- Moment @ cross section c- Distance from neutral axis to outer surface I cross section moment of inertia = (do4 di4) 64

Axial Stress = Force Area

Shear Stress = Force in Shear Shear Area

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0BULONGITUDINAL PRESSURE STRESS

PL = F / A = Pd/4t

1BUHOOP PRESSURE STRESS

PH = F = P d

A 2 t

d outside diameter inside 1 [ F = 0 ] 2 F = Pdi L PH = Pdi L = Pdi 2t L 2t

hoop pressure stress LAME

PH = Pri2 + L ri2 ro2 P / r2 ro2 - ri2

r = position thru the thickness

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1 program CAESAR II 4 option ID, OD, MEAN LAMES_EQ conservative base hoop stress on OD ID

piping stress analysis CAESAR II TOOL main menu CAESAR II Version 5.00 Configures/Setup dialog box 1

1 diameter hoop stress CAESAR II

ULongitudinal Stress longitudinal stress

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bending , axial pressure longitudinal stress

U.S Code longitudinal stress

ASME B31.3 stress Sustained Stress combine stress B31.1 Sustained Stress

ASME Code Sustained Load longitudinal stress Sustained load Sustained Stress (SL) U1.3 CODE COMPLIANCE BASICS : ASME CODE

1. Sustained ( or Primary ) Stress Failure 2. Expansion (or Secondary ) Stress Failure

Mc + F + Pd I A 4t Bending axial pressure

Mc + Pd I 4t Bending pressure

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U PRIMARY STRESS 1. primary stress plastic deformation rupture.

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2. (weight) (pressure) Allowable limits sustained stresses yield stress material

3. (fatigue)

4. cyclic

U SECONDARY STRESS 1.

(thermal expansion) 2. crack

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U OCCASIONAL STRESS (wind), (earthquakes), steam

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water hammer, Pressure Safety Valve (PSV)

U1.4 CODE STRESS ALLOWABLE : 3B Power Plant Code B31.1 Process Plant Code B31.3 4B Process Plant Power Plant Code B31.1 B31.3 code B31.3 Code stress allowable

5BUTHE SUSTAIN ALLOWABLE STRESS 6B hot yield stress factor sustained

stresses materials elastic limit operating design

SL = Stress sustained load Sh = Hot Allowable stress 0.666 Sy 0.25 Su Sh table A-1 ASME B31.3 carbon steel A53 Gr.B 200 Sh = 20000 psi. SI 145 137.93 N/mm2 145 145.037743897 piping stress package ASME Code ASME B31.1 , B31.3

SL < Sh

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7BUTHE EXPANSION ALLOWABLE STRESS RANGE U

8B yield stress safety factor , cyclic reduction factor mean stress total stress range ( expansion sustained) set yield stress

SA = Allowable Displacement Stress Range

f = Cyclic reduction factor for fatigue from Table 302.3.5 (B31.3 edition 2002)

Sc = Cold allowable stress Sh = Hot allowable stress SL = Longitudinal Stress f code B31.1-2004 table 102.3.2

f = 1.0 7000 f = 0.9 7000 14000 f = 0.8 14000 22000 f = 0.7 22000 45000 f = 0.6 45000 100000 f = 0.5 100000

B31.3-2002 table 302.3.5 B31.1 Edition B31.3-2004 plot graph Fig. 302.3.5 B31.3 Edition 2004 f 1 Ferrous material minimum tensile strength 75000 psi (517 MPa) 371

SA = f ( 1.25 Sc + 1.25 Sh SL )

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4 f ASME Code B31.3 Edition 2004

7000 relief valves relief valve operating condition operate shut down 1

9BUTHE OCCASIONAL STRESS U (seismic) wind load, water hammer 7 10B Allowable stress ASME Code Sh 10 30 % 1.1Sh 1.33Sh code B31.1 1.15Sh -1.2 Sh B31.3 1.3 Sh B31.1 Power Piping safety factor B31.3 Process Piping

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U1.5 Check Piping Stress U

1. sustained stress (SL) primary load weight pressure

2. expansion stress (SE)

3. Sustained Stress 1 allowable stress : Sh SL Sh

4. Expansion Stress (SE) 2 allowable

a. UB31.3U SA = f (1.25Sc + 0.25Sh) ___ (B31.3 Eq.1a)

SL Sh SA

SA = f (1.25Sc + 1.25Sh SL ) ___ (B31.3 Eq.1b)

SE < f (1.25Sc + 1.25Sh SL )

b. UB31.1U SA = f (1.25Sc + 0.25Sh) _____(B31.1 Eq.1) B31.1 SL Sh allowable SA + f (Sh - Sc) SA

SE < SA + f (Sh - Sc) ___ (B31.1 Eq.13b)

3 SL Sh Code B31.3 CAESAR II report Eq.1b Eq.1a Code B31.1 Eq.13b Eq.1

5. occasional load stress kSh k 1.1 1.3

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Critical line critical Non critical line critical line UCAESAR II Output Stress Analysis Report

CAESAR II SL Sh SE SA

Carbon Steel ASTM A106 Grade B Code B31.1 stress Stress Node 40 120 1.5

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5 node 120 stress

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6 Stress report run static analysis maximum stress sustained load node 120 7971.7 lb/sq.in ( psi) allowable hot stress (Sh) 17100 psi.

stress (SL) (Sh) 46.6 % step 3 1.5

SL 16000 psi report

ASME B31.1 ASME CAESAR II Sh 15000 psi What do you expect to see?

Sh

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CAESAR II feedback error

stress check passed input run output check stress

piping stress piping stress analysis CAESAR II AUTOPIPE

nozzle load allowable vendor TLP 110 MW vendor steam turbine nozzle load allowable nozzle load 150 N. 9.81 15.3 kg. 20 ( ) nozzle steam turbine vendor nozzle 150 N. valve . steam turbine

SL Sh SE SA

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7 stress expansion case

7 report sustained stress Expansion stress stress node 50 SE = 11034.5 psi SA = 39632.2 psi ASME Code B31.1

SA = f(1.25Sc+0.25Sh) Sc=17100 psi Sh =17100 psi

SA = 1(1.25x17100+0.25x17100) SA = 25650 psi SL < Sh allowable Allowable = SA + f(Sh SL)

Allowable = 25650+ 1x(17100-3117.8) Allowable = 39632.2 psi

Allowable Stress Expansion Case

SE =11034.5

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node 50 SL =3117.8 psi sustain stress report Figure 8

8 SL node 50 3117.8 psi

SL = 3117.8 psi

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9 SE node 50 11034.5 psi 9 expansion stress (SE) node node 50 SE 11034.5 psi 4 SE allowable 39632.2 psi node 50 expansion stress node 120 allowable expansion stress range ASME Code B31.1

SA = f(1.25Sc+0.25Sh) Sc=17100 psi Sh =17100 psi

SA = 1(1.25x17100+0.25x17100) SA = 25650 psi SL < Sh allowable Allowable = SA + f(Sh SL)

Allowable = 25650+ 1x(17100-7971.7) Allowable = 34778.3 psi

SE = 11034.5 psi

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CAESAR II report 11

allowable stress range ASME B31.3

SA = f (1.25Sc + 1.25Sh SL ) ___ (B31.3 Eq.1b)

SA = 1(1.25x17100+1.25x17100-7971.7) SA = 34778.3 psi

Allowable Expansion Stress Range power plant (B31.1) process plant (B31.3)

10 Stress report sustained stress case

SL SH

SL=7971.7 psi node 120 SA Expansion Stress

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11 Stress report expansion stress case

U1.6 (Piping Stress Analysis Method) ASME B31.3 3

1. UBy Visual InspectionU His pass experience

2. UApproximate MethodU

Table ,Chart

SA =f[1.25(Sc+Sh)-SL]

SA=34778.3 psi node 120

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3. UComprehensive AnalysisU stress

piping stress engineer CAESAR II, Autopipe Editpipe Tractebel, etc. CAESAR II

Code Chart piping stress engineer critical line list

Chart Stress Method Process Plant Layout and Piping Design Ed Bausbacher & roger Hunt

(computer analysis)

Visual Analysis or

judgement

Manual

10 NPS Pipe with 400 F

critical line

comprehensive computer analysis

400 F

10

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Computer Analysis Criteria

rotating equipment pipe size 3 critical line stress comprehensive analysis CAESAR II Poyry Energy Ltd. (Thailand). Technip Simflex Tractebel Edit Pipe CAESAR II

chart guide line 10 400 by visual analysis young piping stress engineer

U (loss containment) computer analysis 21 80

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Code B31.1 B31.3 Appendix B 3 Code B31.4, B31.8 EN13480-3