Pv Design Instruct

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Overview of Pressure Vessel Design

Instructors Guide


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CONTACT INFORMATION

ASME Headquarters1-800-THE-ASME

ASME Professional Development1-800-THE-ASME

Eastern Regional Office Southern Regional Office8996 Burke Lake Road Suite L102 1950 Stemmons Freeway Suite 5068Burke, VA 22015-1607 Dallas, TX 75207-3109

703-978-5000 214-800-4900800-221-5536 800-445-2388

703-978-1157 (FAX) 214-746-4902 (FAX)

Midwest Regional Office Western Regional Office1117 S. Milwaukee Avenue 119-C Paul DriveBuilding B, Suite 13 San Rafael, CA 94903-2022Libertyville, IL 60048-5258 415-499-1148

847-680-5493 800-624-9002800-628-6437 415-499-1338 (FAX)847-680-6412 (FAX)

Northeast Regional Office International Regional Office326 Clock Tower Commons 1-800-THE-ASME

Route 22Brewster, NY 10509-9241845-279-6200800-628-5981845-279-7765 (FAX)

You can also find information on these

courses and all of ASME, including ASME

Professional Development, the Vice

President of Professional Development,

and other contacts at the ASME Web

site......

http://www.asme.org

You can also find information on these

courses and all of ASME, including ASME

Professional Development, the Vice

President of Professional Development,

and other contacts at the ASME Web

site......

http://www.asme.org


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By:

Vincent A. Carucci

Carmagen Engineering, Inc.

Copyright 1999 by

All Rights Reserved


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TABLE OF CONTENTS

Abstract 5

Introduction..6

Organizing Unit Responsibilities..7

Instructor Guidelines and Responsibilities.9

Overview of Pressure Vessel Design Outline/

Teaching Plan11

Instructor Notes.13

Appendix A: Reproducible Overheads

Appendix B: Course and Instructor Evaluation Form

Appendix C: Continuing Education Unit (CEU) Submittal Form

Course Improvement Form

Instructors Biography Form


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ABSTRACT

Pressure vessels are typically designed, fabricated, installed, inspected, and testedin accordance with the ASME Code Section VIII. Section VIII is divided into threeseparate divisions. This course outlines the main differences among the divisions.

It then concentrates on and presents an overview of Division I. This course alsodiscusses several relevant items that are not included in Division I.


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INTRODUCTION

This Overview of Pressure Vessel Design course is part of the ASME InternationalCareer Development Series an educational tool to help engineers and managerssucceed in todays business/engineering world. Each course in this series is a 4-

hour (or half-day) self-contained professional development seminar. The coursematerial consists of a participant manual and an instructors guide. The participantmanual is a self-contained text for students/participants, while the guide (thisbooklet) provides the instructional material designed to be presented by a localknowledgeable instructor with a minimum of preparation time.

The balance of this instructors guide focuses on:

1. Organizing Unit Responsibilities

2. Instructor Guidelines and Responsibilities

3. Comprehensive teaching materials which may be used as is or adaptedto incorporate experiences and perspective of the instructor.

Welcome to the ASME International Career Development Series! We wish you allthe best in your presentation, operation and delivery of this course.


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Suggested Outline/Teaching Plan

Time,

min.

Major

Interval

Class Segment Sub-Segment

Interval

Sub-SegmentOverheads/Participant

Pages5 Introduction/Logistics

Outline ModuleOV 1Part. 65

10 Introduction

5 Module based primarily on theASME Code Section VIII, Division

1. Divisions 2 and 3 will be brieflydescribed

OV 2Part. 65

10 Main Pressure Vessel Components OV 3-9Part. 67

10 Scope of ASME Code Section VIII

Division 1

Division 2

Division 3

OV 10-13Part. 75

25 General

5 Structure of Section VIII, Division 1 OV 14Part. 78

15 Material Selection Factors

Strength

Corrosion Resistance

Resistance to Hydrogen Attack

Fracture Toughness

Fabricability

OV 15-31Part. 79

20 Materials of Construction

5 Maximum Allowable Stress OV 32-34

Part. 87

10 Exercise 10 Material Selection Based On FractureToughness

OV 35-38Part. 91

10 Break 10

10 Design Conditions and Loadings

Pressure

Temperature

Other Loadings

OV 39-43Part. 92

25 Design for Internal Pressure

Weld Joints

Cylindrical Shells

Heads

Conical SectionsSample Problem

OV 44-55Part. - 98

55 Design

20 Design for External Pressure andCompressive Stresses

Cylindrical Shells Other Components

Sample Problem

OV 56-65Part. 109


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Suggested Outline/Teaching Plan, continued

Time,

min.

Major

Interval

Class Segment Sub-Segment

Interval

Sub-SegmentOverheads/

ParticipantPages

10 - 50 Major Break Lunch or Major Break

15 Exercise 15 Required Thickness for Internal

Pressure

OV 66-68

Part. - 118

20 Reinforcement of Openings (IncludeSample Problem)

OV 69-84Part. 119

10 Flange Rating (Including Sample

Problem)

OV 85-90

Part. 127

15 Flange Design OV 91-97Part. 131

50 Design(Contd.)

5 Maximum Allowable WorkingPressure (MAWP)

OV 98Part. 138

10 Break

10 Local Loads OV 99

Part. 139

20 Other Design

Considerations

10 Vessel Internals OV 100-102Part. 141

10 Acceptable Welding Details OV 103-106Part. 143

20 Fabrication

10 Postweld Heat Treatment

(PWHT)Requirements

OV 107

Part. 146

10 Inspection OV 108-113Part. 148

15 Inspection andTesting

5 Pressure Testing OV 114-115

Part. 152

10 Closure 10 SummaryQuestionnaire (fill in and collect)CEU Form (hand out individual

responsibility to return)

OV 116Part. - 155


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Instructors Personal Notes

Instructors Outline

1. Course discusses pressure vesseldesign and is introductory in nature.

2. Based on ASME Code Section VIII.

3. Preliminary emphasis is on Division1 but Divisions 2 and 3 arehighlighted.

4. Introduces several items that are notcovered in the ASME Code.

Major Learning Points

Course Introduction

1

OVERVIEW OF

PRESSURE VESSEL DESIGN

By: Vincent A. Carucci

Carmagen Engineering, Inc .


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Instructors Outline

1. The objective: Provide a generalknowledge of design requirementsfor pressure vessels.

2. This is not a comprehensive course.It provides sufficient information for

management personnel to have anoverall understanding of this

subject. Individuals having moredetailed responsibility will receive asolid starting point to proceedfurther.

3. Review outline.

4. Establish schedule.

5. Participation is key:

Questions

Discussion/interaction


Establish course objectives.

Outline course content, a road map.

2

Course Overview

General

Materials of Construction

Design

Other Design Considerations

Fabrication

Inspection and Testing


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Instructors Outline

1. Describe what a pressure vessel is.

2. Note that pressure vessels are usedin a wide variety of industries. Theycan be designed for a wide variety ofconditions and in a broad range of

sizes.


Define pressure vessels.

Identify wide variety of industrialapplications.

3

Pressure Vessels

Containers for fluids under pressure

Used in variety of industries

Petroleum refining

Chemical

Power

Pulp and paper

Food


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Instructors Outline

1. Use this and following overheads todescribe main pressure vesselcomponents and shapes.

2. Shell is primary component thatcontains pressure. Curved shape.

3. Vessel always closed by heads.

4. Components typically weldedtogether.

5. Vessel shell may be cylindrical,spherical, or conical.

6. Multiple diameters, thicknesses ormaterials are possible.

7. Saddle supports used for horizontaldrums.

Spreads load over shell.

One support fixed, other slides.


Main pressure vessel components andconfigurations.

4

Horizontal Drum on

Saddle Supports

Figure 2.1

Nozzle

ShellA

A

Head

SaddleSupport

(Fixed)

Saddle Support

(Sliding)

Head

SectionA-A


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Instructors Outline

1. Most heads are curved shape forstrength, thinness, economy.

2. Semi-elliptical shape is mostcommon head shape.

3. Small vertical drums typicallysupported by legs.

Typically maximum 2:1 ratio ofleg length to diameter.

Number, size, and attachmentdetails depend on loads.


Main pressure vessel components andshapes.

5

Vertical Drum

on Leg Supports

Figure 2.2

Head

Shell Nozzle

Head

SupportLeg


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Instructors Outline

1. Nozzles used for:

Piping systems

Instrument connections

Manways

Attaching other equipment

2. Ends typically flanged, may bewelded.

3. Sometimes extend into vessel.



6

Tall Vertical Tower

Figure 2.3

Trays

Nozzle

Head

Shell

Nozzle

Cone

Shell

Nozzle

NozzleSkirtSupport

Head


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Instructors Outline

1. Skirt supports typically used for tallvertical vessels:

Cylindrical shell

Typically supported from grade

2. General support design (not just forskirts)

Design for weight, wind,earthquake.

Pressure not a factor.

Temperature also aconsideration for materialselection and thermalexpansion.



7

Vertical Reactor

Figure 2.4

Inlet

Nozzle

Head

Shell

UpperCatalyst

Bed

Catalyst Bed

Support Grid

Lower

Catalyst

Bed

Outlet

Collector

Head

Support

Skirt

Outlet

Nozzle


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Instructors Outline

1. Spherical storage vessels typicallysupported on legs.

2. Cross-bracing typically used toabsorb wind and earthquake loads.



8

Spherical Pressurized

Storage Vessel

Figure 2.5

CrossBracing

Support

Leg

Shell


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Instructors Outline

1. Vessel size limits for lug supports:

1 10 ft diameter

2:1 to 5:1 height/diameter ratio

2. Vessel located above grade.

3. Lugs bolted to horizontal structure.


Main pressure vessel components andconfigurations.

9

Vertical Vessel on

Lug Supports

Figure 2.6


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Instructors Outline

1. Section VIII is most widely usedCode.

2. Assures safe design.

3. Three divisions have differentemphasis.


Define scope of ASME Code SectionVIII.

10

Scope of ASME Code

Section VIII

Section VIII used worldwide

Objective: Minimum requirements for safe

construction and operation

Division 1, 2, and 3


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Instructors Outline

1. Review scope of Division 1.

2. Division 1 not applicable below 15psig.

3. Additional rules required above 3000psig.

4. Items that are connected to pressure

vessels not covered by Division 1,except for:

Their effect on pressure part.

Welded attachment to pressurepart.


Scope of Division 1

Exclusions from scope

11

Section VIII Division 1

15 psig < P 3000 psig Applies through first connection to pipe

Other exclusions

Internals (except for attachment weld to vessel)

Fired process heaters

Pressure containers integral with machinery

Piping systems


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Instructors Outline

1. Review differences betweenDivisions 1 and 2.

2. Division 2 allowable membranestress is higher.

3. Division 2 requires more complexcalculations.

4. Division 2 does not permit somedesign details that are permitted inDivision 1.

5. Division 2 requires more stringentmaterial quality control, fabrication,

and testing requirements.


Differences between Division 1 and 2.

12

Section VIII, Division 2,

Alternative Rules Scope identical to Division 1 but

requirements differ

Allowable stress

Stress calculations

Design

Quality control

Fabrication and inspection

Choice between Divisions 1 and 2 based oneconomics


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Instructors Outline

1. Review application of Division 3.

2. Newest Division of Section VIII andhas least applicability.

3. After this point, this course onlyaddresses Division 1 requirementswhen code-specific items arediscussed.


Scope of Division 3

13

Applications over 10,000 psi

Pressure from external source, processreaction, application of heat, combination

of these

Does not establish maximum pressurelimits of Division 1 or 2 or minimum limits

for Division 3.

Division 3, Alternative Rules

High Pressure Vessels


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Instructors Outline

1. Review Division 1 organization

2. Fabrication methods:

Welded

Forged

Brazed

3. Material classes Carbon and low-alloy steel

Non-ferrous metals

High alloy steel

Cast iron

Clad and lined material

Ductile iron

Heat treated steels Layered construction

Low-temperature material

4. Highlight several mandatory andnonmandatory appendices.


Basic organizational structure ofDivision 1.

14

Structure of Section VIII,

Division 1 Subsection A

Part UG applies to all vessels

Subsection B

Requirements based on fabrication method

Parts UW, UF, UB

Subsection C

Requirements based on material class

Parts UCS, UNF, UHA, UCI, UCL, UCD, UHT,ULW, ULT

Mandatory and Nonmandatory Appendices


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Instructors Outline

1. ASME Code does not specifyparticular materials to use in eachapplication. Owner must do this.

2. ASME Code specifies permittedmaterials and the requirements that

these must meet.


Primary factors that influence pressurevessel material selection.

15

Material Selection Factors

Strength


Resistance to Hydrogen Attack

Fracture Toughness

Fabricability


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Instructors Outline

1. Strength: Materials ability towithstand imposed loading.

2. Higher strength material thinnercomponent.

3. Describe properties that are used todefine strength.


Material strength and pressure vesseldesign.

16

Strength

Determines required component thickness

Overall strength determined by:

Yield Strength

Ultimate Tensile Strength

Creep Strength

Rupture Strength


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Instructors Outline

1. Corrosion is thinning of metal.

2. Adding extra component thickness(i.e., corrosion allowance) is mostcommon method to addresscorrosion.

3. Alloy materials are used in serviceswhere corrosion allowance would be

unreasonably high if carbon steelwere used.


Importance of corrosion resistance inmaterials selection.

17


Deterioration of metal by chemical action

Most important factor to consider

Corrosion allowance supplies additionalthickness

Alloying elements provide additional

resistance to corrosion


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Instructors Outline

1. Low-temperature H2 attack cancause cracking.

2. Higher temperature H2 attack causesthrough-thickness strength loss andis irreversible.

3. H2 attack is a function of H2 partialpressure and design temperature.

Increased alloy content (i.e., Cr)increases H2 attack resistance.

Reference API-941 for NelsonCurves.


Hydrogen attack can damage carbonand low-alloy steel.

18

Resistance to

Hydrogen Attack

At 300 - 400F, monatomic hydrogenforms molecular hydrogen in voids

Pressure buildup can cause steel to crack

Above 600F, hydrogen attack causes

irreparable damage through component

thickness


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Instructors Outline

1. Describe brittle fracture asequivalent to dropping a piece ofglass.

2. Material selection must ensure thatbrittle fracture will not occur.


Brittle fracture and its consequences.

19

Brittle Fracture

and Fracture Toughness Fracture toughness: Ability of material to

withstand conditions that could cause

brittle fracture

Brittle fracture

Typically at low temperature

Can occur below design pressure

No yielding before complete failure


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Instructors Outline

1. A brittle fracture will occur the firsttime the appropriate conditionsoccur.

2. Brittle fracture occurs withoutwarning and is catastrophic.


Three conditions that are required for abrittle fracture to occur.

20

Brittle Fracture and

Fracture Toughness, contd

Conditions required for brittle fracture

High enough stress for crack initiation and

growth

Low enough material fracture toughness attemperature

Critical size defect to act as stress

concentration


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Instructors Outline

1. Describe influence of material andtemperature factors on fracturetoughness.

2. Other factors increase brittle fracturerisk.


Primary factors that influence materialfracture toughness.

21

Factors That Influence

Fracture Toughness Fracture toughness varies with:- Temperature

- Type and chemistry of steel

- Manufacturing and fabrication processes

Other factors that influence fracture

toughness:

- Arc strikes, especially if over repaired area

- Stress raisers or scratches in cold formed thickplate


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Instructors Outline

1. Charpy V-Notch test is most widelyused measure of material fracturetoughness.

2. Describe test set-up.


Charpy V-Notch testing.

22

Charpy V-Notch Test Setup

Starting Position

Hammer

Scale

Pointer

End of swing

Anvil

Specimen

h'

h'


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Instructors Outline

1. ASME Code contains brittle fractureevaluation procedure.

2. Review components to be included -only items that relate to structuralintegrity of pressure-containing

shell.


Components to consider is ASME Codebrittle fracture evaluation.

23

ASME Code and

Brittle Fracture Evaluation

Shells

Manways

Heads

Reinforcing pads

Backing stripsthat remain inplace

Nozzles

Tubesheets

Flanges

Flat cover plates

Attachments essentialto structural integritythat are welded topressure parts

Components to consider


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Instructors Outline

1. Describe the distinction betweenMDMT and CET.

MDMT is a materialproperty.

CET is an environmental factor.

2. Important to understand thisdistinction.


Two temperatures to be considered inbrittle fracture evaluation.

24

Temperatures to Consider

Minimum Design Metal Temperature

(MDMT)

Lowest temperature at which component has

adequate fracture toughness

Critical Exposure Temperature (CET)

Minimum temperature at which significant

membrane stress will occur


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Instructors Outline

1. Outline ASME procedure.

2. Details described in followingoverheads.


Simplified ASME brittle fractureevaluation procedure.

25

Simplified ASME

Evaluation Approach Material specifications classified into

Material Groups A through D

Impact test exemption curves

For each Material Group

Acceptable MDMT vs. thickness where impact

testing not required

If combination of Material Group andthickness not exempt, then must impact test

at CET


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Instructors Outline

1. Materials are grouped based oncommon fracture toughnessproperties.

2. Groups A through D move fromworst to best fracture toughness.

3. Point out several common materials.

SA-516 Gr. 65 and 70 are CurveB if not normalized.

Most pipe, fittings and forgingsare Curve B.


Material group classifications for brittlefracture evaluations.

26

Material Groups

Table 3.1 (Excerpt)

MATERIAL

GROUP APPLICABLE MATERIALSCurve A A l l c a r b o n a n d l o w a l lo y s t e e l p l a t es , s t r u c t u ra l s h a p e s , a n d b a r s n o t

l i s t ed i n Curves B , C & D

S A - 2 1 6 G r . W C B & W C C , SA - 2 1 7 G r . W C 6 , i f n o r ma l i z e d a n d t e m p er e do r w a t e r - q u e n c h e d a n d t e m p e r e d

Curve B S A - 2 16 G r . W C A , i f n o r m al i z ed a n d t e m p e r ed o r w a t e r - q u e n c h e d a n dt e m p e r e d

S A - 2 1 6 G r . W C B & W C C f o r m a x im u m t h i c k ne s s o f 2 i n . , if p r o d u c e d

t o f i n e g r a i n p r a c t i c e a n d w a t e r - q u e n c h e d a n d t e m p e r e d

S A - 28 5 Gr . A & B

S A- 41 4 Gr . A

S A- 5 15 G r. 6 0

S A - 5 16 G r . 6 5 & 7 0 , i f n o t n o rm a l iz e d

E x c e p t f o r c a s t s t e e l s , a l l m a t e r i a l s o f C u r v e A i f p r o d u c e d t o f i n e

g r a i n p r a c t i c e a n d n o r m a l i z e d w h i c h a r e n o t i n c l u d e d i n C u r v e s C & D

A l l p i p e , f i tt i n g s , f o r g i n g , a n d t u b in g w h i c h a r e n o t i n c lu d e d i n C u r v e sC & D


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Instructors Outline

1. Identify other common materials.

SA-516 Gr. 55 and 60 are CurveC if not normalized.

SA-516 (all grades) is Curve D ifnormalized.

2. Highlight points.

Lower strength grades of samespecification have betterfracture toughness.

Normalization improves fracturetoughness.


Material group classifications for brittlefracture evaluations.

27

Material Groups, contd

Table 3.1 (Excerpt)

MATERIAL

GROUP APPLICABLE MATERIALS

Curve C S A - 1 8 2 G r . 2 1 & 22 , i f n o r m a l i ze d a n d t e m pe r e d S A -3 02 G r. C & D

S A - 3 3 6 G r. F 2 1 & F 2 2 , i f n or m a l i z ed a n d t e m pe r e d

S A - 3 8 7 G r . 2 1 & 22 , i f n o r m a l i ze d a n d t e m pe r e d

S A - 5 1 6 G r . 5 5 & 6 0 , i f n ot n o r m al i z e d

S A -5 33 G r. B & C

S A -6 62 Gr . A

A l l m a t e r i a l o f C u r ve B i f p r o d u c e d t o f i n e g r ai n p r a c t i c e a n d

n o r m a l i z e d w h i c h a r e n o t i n c l u d e d i n C u r v e D

Curve D S A- 20 3 S A-537 C l. 1 , 2 & 3

SA-508 Cl . 1 S A - 6 1 2 , i f n o rm a l i z e d

S A -5 16 , i f n o rm al iz e d S A - 6 6 2 , i f n o rm a l i z e d

SA-524 Cl . 1 & 2 S A-7 3 8 G r . A

Bolting Se e F ig u re U CS-6 6 o f th e A SME Cod e Se c t io n V I I I , D iv . 1 , fo r im p ac t

and Nuts t e s t e x e m p t i o n t e m p e r a t u r e s f o r s p e c i f i e d m a t e r i a l s p e c i f i c a t i o n s


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Instructors Outline

1. Describe relationship betweenMaterial Group, componentthickness, and MDMT.

2. Impact testing not required if point is

at or below curve (i.e., OK if MDMT CET).

3. Example: 1.5 in. thick Group B

material does not require impact

testing if CET 50F.

4. If not exempt, must impact testmaterial at CET.

5. Exemption means there is enoughexperience that material hasadequate fracture toughness withoutneed for further testing.


Impact test exemption curves.

28

Impact Test Exemption Curves

for Carbon and Low-Alloy Steel

Figure 3.1

Nominal Thickness, in.

(Limited to 4 in. for Welded Construction)

0.394 1 2 3 4 5

140

120

100

80

60

40

20

0

-20

-40

-55-60

-80

MinimumD

esignMetalTemperature,

F

Impact testing required

D

C

BA


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Instructors Outline

1. Review additional requirements.

2. Note that most flanges will notrequire impact testing.


Additional impact test requirements.

29

Additional ASME Code ImpactTest Requirements

Required for welded construction over 4 in.thick, or nonwelded construction over 6 in.

thick, if MDMT < 120F Not required for flanges if temperature

-20F Required if SMYS > 65 ksi unless

specifically exempt


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Instructors Outline

1. Review additional requirements.

2. PWHT reduces MDMT by 30Fprovided PWHT not required by

Code and resulting MDMT -55F.

3. Can take MDMT credit if componentthickness greater than needed (i.e.,calculated stress < allowable stress).


Additional impact test requirements.

30

Additional ASME Code

Impact Test

Requirements, contd Not required for impact tested low

temperature steel specifications

May use at impact test temperature

30F MDMT reduction if PWHT P-1 steel

and not required by code

MDMT reduction if calculated stress

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Pv Design Instruct