PIPING MATERIALMODULAR FABRICATION YARD

PIPING MODULE – PART II

INTRODUCTION

Piping Materials can be classified as

Metals (ferrous) : CS, SS, Alloy Steel Metals (non-ferrous) : Cupro Nickel, Al Non-metals : PVC, cement, glass Materials are selected based on their mechanical

and metallurgical properties. Mechanical properties: strength, ductility,

hardness, brittleness, toughness Metallurgical properties: Chemical composition,

weldability

CARBON STEEL

Low Carbon Steel : C < 0.15%Condenser Tubes : SA 179Weldability : Excellent

Mild Steel : 0.15% < C < 0.30%Pipes : SA 106 GR BWeldability: Good

CARBON STEEL

Medium Carbon Steel : 0.3% < C < 0.5%Machinery PartsWeldability: Fair

High Carbon Steel : 0.5% < C < 1%Dies & punch, ToolsWeldability: Poor

Steel : Carbon < 2% Cast Iron : Carbon > 2%

Weldability As Carbon % increases , weldability decreases Effect of carbon & other elements on the weldability of

carbon steels can be estimated by equating them to anequivalent amount of carbon.

Carbon Equivalent:Ceq = C + Mn/6 + Cr + Mo+ V + Cu + Ni

5 15 Killed Steel

During Steel making process oxygen present is removedby adding Silica (De oxidizing agent).

ALLOY STEEL

Addition of elements such as Cromium, Nickel,Molybdenum, Manganese, Silicon along with heattreatment improves the properties of steels suchas mechanical strength, corrosion resistance,toughness

Steel is a ferrous alloy having main constituentIron and other alloying elements / Impurities likeCarbon, Manganese, Phosphorus, Sulfur, Silicon,Chromium, Nickel, Molybdenum

ALLOY STEELSolid solubility in ferrous alloys :Interstitial solid solution :Carbon with Iron forms interstitial solid solution(Carbon steel)Substitutional solid solution :Cromium and Nickel with iron forms Substitutional

solid solution (Stainless steel)Low alloy steels :Alloying elements < 5%High alloy steels :Alloying elements > 5%.

STAINLESS STEEL Alloy of iron with Cromium content more than

11% and less than 30% and other alloyingelements Nickel, Molybdenum etc is calledstainless steel.

Stainless steel has excellent resistant tocorrosion.

Stainless steel becomes corrosion resistant(passive) because of formation of un-reactivefilm which adheres tightly to the surface of metal.This can be chromium oxide (Cr2O3) film thatacts as a barrier protecting metal againstcorrosion.

EFFECT OF ALLOYING ELEMENTS

Chromium : Increases resistance to Oxidation.Nickel : Increases resistance to mineral acid,

produces tightly adhering high temperatureoxides.

Molybdenum: Increases resistance to chloride.Copper : Increases resistance to sulphuric acid.Titanium : Stabilize carbides to prevent formation of

chromium carbideNiobium : Stabilize carbides to prevent formation of

chromium carbide

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S i l i c o n ↑ ↑ ↑ ↑ ↓ ↓ ↑ ↑ ↑ ↑ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓M a n g a n e s e i n

p e r l i t . s t e e l s ↑ ↑ ↑ • • ↑ • ↓ • ↓ ↓ ↑ ↓ •M a n g a n e s e i n

a u s t e n i t . s t e e l s . ↓ ↓ ↓ ↑ ↓ ↑ ↑ ↑ – – – ↓ ↓ – – ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓C h r o m i u m ↑ ↑ ↑ ↑ ↑ ↑ ↓ ↓ ↑ ↑ ↓ ↓ ↓ ↑ ↑ ↑ ↓ – ↓ ↓ ↓

N i c k e l i np e r l i t . s t e e l s ↑ ↑ ↑ • • – ↑ ↓ ↓ – ↓ ↓ ↓ ↓ ↓

N i c k e l i na u s t e n n i t . s t e e l s ↓ ↓ ↑ ↓ ↑ ↑ ↑ ↑ ↑ ↑ – ↑ ↑ ↑ ↓ ↓ – – ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓

A l u m i n u m – – – – ↓ – – – – – ↓ ↓ – ↓ ↓ T u n g s t e n ↑ ↑ ↑ ↓ • – ↑ ↑ ↑ ↓ ↓ ↑ ↑ ↑ ↑ ↑ ↓ ↓ ↓ ↓ ↓ ↓V a n a d i u m ↑ ↑ ↑ • ↑ ↑ ↑ ↑ ↓ ↓ ↑ ↑ ↑ ↑ ↑ ↑ ↑ – ↓

C o b a l t ↑ ↑ ↑ ↓ ↓ – ↑ ↑ ↑ ↑ – ↑ ↑ ↑ ↓ • ↓M o l y b d e n u m ↑ ↑ ↑ ↓ ↑ – ↑ ↑ ↓ ↓ ↑ ↑ ↑ ↑ ↑ ↓ ↓ ↑ ↑

C o p p e r ↑ ↑ ↑ ↑ • • – ↑ – – – ↓ ↓ ↓ • •S u l p h u r – – – ↓ ↓ – – – – – ↓ ↓ ↓ ↑ ↑ ↑ –

P h o s p h o r o u s ↑ ↑ ↑ ↓ ↓ ↓ ↓ – – – – – ↓ ↑ ↑ –

T H E E F F E C T O F A L L O Y I N G E L E M E N T S O N T H E P R O P E R T I E S O F S T E E L

↑ = In c r e a s e ↓ = D e c r e a s e • = c o n s t a n t - = n o t c h a r a c t e r i s t i c o r u n k n o w n S e ve r a l a r r o w s = m o r e i n t e n s i ve e ffe c t

STAINLESS STEEL

Classification based on

1. Alloying Constituents

2. Metallurgical Microstructure

3. Degree of sensitization

STAINLESS STEEL

Alloying constituents

200 Series : Cr. Ni - Mn group( Mn replaces a portion of Ni)

300 Series : Cr - Ni group

400 Series : Straight Chromium Group( Cr < 30%)

STAINLESS STEEL

Metallurgical microstructure.Austenitic SS:Alloy of Cr, Ni, FeNon MagneticHigh Corrosion resistance at temp up to 1500FHardenable by cold workingCrystallographic form-Face centered Cubic lattice

(fine grain structure)Possess high impact strength at low tempEx: Type 304, 304L,316,316L

STAINLESS STEEL

Ferritic SS:Alloy of Cr, FeMagneticNon Hardenable by heat treatment Crystallographic form- Body centered cubic lattice

(coarse grain structure)For marine application. (10.5% Cr alloy with no nickel)Contains high carbon, therefore brittle & relatively poor

corrosion resistanceHas resistance to chlorides stress corrosion crackingEx: Type 409, 430, 439

STAINLESS STEEL

Martensitic SS. High hardness (carbon added to the alloy) Corrosion resistant Heat treatable to high hardness level Crystallographic form-distorted lattice Type 410,420.

STAINLESS STEEL

Precipitation Hardened SS Magnetic Heat treatable to high strength. Weldable and corrosion resistant similar to type

304 Ex:-17-7PH, 17-4PH

STAINLESS STEEL

Duplex SS Contain both Austenite & Ferrite in microstructure. Ni (4 to

7%). When ferrite- Resistant to chloride stress corrosion cracking. When Austenite-Sensation to chloride stress corrosion

cracking. High strength, Good corrosion resistance Ex: Alloy 2205, Alloy 255

STAINLESS STEEL

3. Degree of sensitization of grain boundaries

GROUP 1

SS grade 304,316,309,310.They are susceptible to sensitization.

(During welding, flame cutting)

STAINLESS STEEL

GROUP 2

Stabilized stainless steel type 321 &347Grain boundaries sensitization eliminated by alloying

elements like Titanium or Columbium. (BecauseTitanium or Columbium forms carbides first).Columbium (Type 347) is stronger stabilizing agent than

Ti (Type 321), Hence Type 347 is superior to 321

STAINLESS STEEL

GROUP 3

Extra low carbon stainless steel Type 304L, 316LCan be stress relieved, welded & cooled slowly without

significantly increasing their susceptibility to IGC.

1 ) A u s t e n i t i c S ST y p e 3 0 4 S 3 0 , 4 0 0 7 5 , 0 0 0 3 0 , 0 0 0 3 0 2 9 , 0 0 0 , 0 0 0 8 0 R B

T y p e 3 0 4 L S 3 0 , 4 0 3 7 0 , 0 0 0 2 5 , 0 0 0 3 5 2 9 , 0 0 0 , 0 0 0 7 5 R BT y p e 3 1 6 S 3 1 , 6 0 0 7 5 , 0 0 0 3 0 , 0 0 0 3 0 2 8 , 0 0 0 , 0 0 0 8 0 R B

T y p e 3 1 6 L S 3 1 , 6 0 3 7 0 , 0 0 0 2 5 , 0 0 0 3 5 2 8 , 0 0 0 , 0 0 0 7 5 R B

2 ) F e r r i t i c S S T y p e 4 3 0 S 4 3 , 0 0 0 6 0 , 0 0 0 3 0 , 0 0 0 2 0 2 9 , 0 0 0 , 0 0 0 8 5 R B

T y p e 4 3 9 S 4 3 , 0 3 5 6 0 , 0 0 0 3 0 , 0 0 0 2 0 2 9 , 0 0 0 , 0 0 0 9 0 R BT y p e 4 0 9 S 4 0 , 9 0 0 5 5 , 0 0 0 3 0 , 0 0 0 2 0 2 9 , 0 0 0 , 0 0 0 8 5 R B

3 ) D u p l e x S S A l l o y 2 2 0 5 S 3 1 , 8 0 5 9 0 , 0 0 0 6 5 , 0 0 0 2 5 2 9 , 0 0 0 , 0 0 0 3 0 R C 7 0 M o P l u s S 3 2 , 9 5 0 9 0 , 0 0 0 7 0 , 0 0 0 2 0 2 9 , 0 0 0 , 0 0 0 3 0 R C

A l l o y 2 5 5 S 3 2 , 5 5 0 1 , 1 0 , 0 0 0 8 0 , 0 0 0 1 5 3 0 , 5 0 0 , 0 0 0 3 2 R C

4 ) M a r t e n s i t i c S ST y p e 4 1 0 S 4 1 , 0 0 0 1 , 9 0 , 0 0 0 1 , 5 0 , 0 0 0 1 5 2 9 , 0 0 0 , 0 0 0 4 1 R CT y p e 4 2 0 S 4 2 , 0 0 0 2 , 4 0 , 0 0 0 2 , 0 0 , 0 0 0 5 2 9 , 0 0 0 , 0 0 0 5 5 R C

T y p e 4 4 0 L S 4 4 , 0 5 0 2 , 8 0 , 0 0 0 2 , 7 0 , 0 0 0 2 2 9 , 0 0 0 , 0 0 0 6 0 R C

5 ) P r e c i p i t a t i m S S1 7 . 7 P H S 1 7 , 7 0 0 2 , 1 0 , 0 0 0 1 , 9 0 , 0 0 0 5 3 2 , 5 0 0 , 0 0 0 4 8 R C1 7 . 4 P H S 1 7 , 4 0 0 1 , 9 0 , 0 0 0 1 , 7 0 , 0 0 0 8 2 8 , 0 0 0 , 0 0 0 4 5 R C

C u s t o m 4 5 5 S 4 5 , 5 0 0 2 , 3 0 , 0 0 0 2 , 2 0 , 0 0 0 1 0 2 9 , 0 0 0 , 0 0 0 4 8 R C

A L L O Y S U N S N O H A R D N E S S

P R O P E R T IE S O F S T A IN L E S S S T E E L A L L O Y S

E l o n g a t i o n( % ) m i n

Y S( P S I )

U T S( P S I )

M O D U L U SO F

E L A S T I C I T Y

ASTM / ASME Nomenclature

Materials are listed based on their known chemicalcomposition, manufacturing processes, mechanicalstrength etc, in different codes i.e,ASTM, ASME, DIN,MSS etc, and common UNS number

ASTM Standard gives various details of materials likemanufacturing process, Grades, Chemical Composition,and Mechanical Properties.

ASME Code accepts the ASTM materials with someadditional specified properties.

ASTM / ASME Nomenclature

SA 312 TP 304S : ASME approved MaterialA : Ferrous312 : Manufacturing Process No.TP : Tubular Product304 : GradeSA 234 GR WPBS : ASME approved MaterialA : Ferrous234 : Manufacturing Process No.GR : Grade.WP : Wrought ProductB : Grade

ASTM / ASME Nomenclature SA 350 LF 2 : Low Temperature Forging Grade 2

SA 216 WCB : Weldable Casting Grade B

SA 335 P 11 : Pipe Grade 11

SA 182 Gr F11 : Forging Grade 11

SA 351 Gr CF 8 : Centrifugal Cast, Carbon % - 0.08%

SA 351 Gr CF 3 : Centrifugal Cast, Carbon % - 0.03%

SA 351 Gr CF 8M : Centrifugal Cast, Carbon % - 0.08%, Mo

SA 351 Gr CF 3M : Centrifugal Cast, Carbon % - 0.03%, Mo

CORROSION

Corrosion is the tendency of any metal to return to its moststable thermodynamic state i.e. state with most negativefree energy formation. . More simply stated, it is a chemicalreaction of metal with environment to form an oxide,carbonate, sulphate or other stable compound.

Corrosion is broadly classified into two categories: Low temperature corrosion (corrosion at room

temperature and below)High temperature corrosion (corrosion at elevated

temperature including molten metal.)

CORROSION

Classification :

General or uniform corrosion. Localized CorrosionInter granular corrosion (IGC)Pitting corrosioncrevice corrosionStress corrosion crackingMicro biological influenced corrosion.

INTER GRANULAR CORROSION

During Welding:- ( at Temp. 800-1600 F ), Carbonmolecules diffuse to grain boundary & precipitateout of solid solution as chromium carbide at thegrain boundaries. This result in the depletion ofchromium content in the thin envelopesurrounding each grain, Hence Stainless Steelbecomes susceptible to Inter Granular Corrosion& is said to be sensitized.

Corrosion property of sensitized steel can berestored by desensitization i.e. heat above 1600F, & rapid cooling.

Testing Standard: IGC Practice A/B/C/D/E

SULPHIDE STRESS CORROSION CRACKING

A cracking process that requires simultaneous action ofcorrodant and sustained tensile stress.

NACE MR-0175 standard presents metallic materialrequirements for resistance to sulfide stress cracking(SSC)for petroleum production,drilling,gathering,flowlineequipment, and field processing facilities to be used inhydrogen sulfide (H2S)-bearing hydrocarbon services.

Testing Standard: NACE TM- 01/77 Reporting of test result: Curve shall be reported as per

NACE-TM-01-77 for various stress level between 72%and90% of SMYS.

Acceptance Criteria: At 72 % SMYS, time of failure shall notbe less than 720 hrs.

HYDROGEN INDUCED CRACKING

Hydrogen induced cracking (HIC) is also known as coldcracking, delayed cracking or under bead cracking

HIC occurs in piping or vessel as a result of hydrogen pickup in service

It occurs in steels during steel manufacturing, duringfabrication, and in service. It occurs as a result of welding,the cracks are sited either in HAZ of parent material or inthe weld metal it self.

Testing Standard: NACE TM- 02/84

NACENACE: National Association of Corrosion Engineers NACE Standard gives chemical composition, Manufacture, Fabrication

& testing Requirements for Steels intended to be used for SourService environment

Sour service Requirements Steel shall be manufactured by Basic Oxygen Process or Electric arc

furnace Steel to be Killed & fine grained Materials shall be in Normalized Condition Nickel % limited to < 1% Carbon content< 0 .23% Carbon Equivalent < 0.43% Hardness < 22 HRC Sulpher content< 0.002%

Material Selection CriteriaService media Corrosive-sea water, H2S, Ammonia Non Corrosive

Temperature Cryogenic Low temperature Medium temperature High temperature

Pressure Low pressure High pressure

Standard Material specification Additional requirements

Economy Cost Availability Weldability Manufacturability

Material Selection for Temperature

SERVICETEMPERATURE (°F) PLATE PIPE FORGING PRESSURE

BOLTING

CRYOGENIC

TEMP

(-425) – (-321)

SA 240 types304, 304L, 347

SA 312 types304,304L, 347

SA 182 gradesF304, F304L,F347

Bolts: SA 320 gr. B8strain. HardenedNuts: SA 194 gr.8(S5 SA 20)

(-320) – (-151)

SA 240 types 304,340L, 316, 316LSA 353

SA 312 types304, 304L, 316,316L

SA 182 gradesF304, F304L,F316

Material Selection for Temperature (Continued…)

SERVICETEMPERATURE (°F)

PLATE PIPE FORGING PRESSUREBOLTING

LOW

TEMPERATURE

(-150) – (-76) SA 203 GR.D OR E SA 333 GR.3 SA 350 GR.LF3

BOLTS: SA 320GR.L7

NUTS: SA 194GR.4

(-75) – (-51) SA 203 GR.A OR B SA 333 GR.3 SA 350 GR.LF3

(-50) – (-21) SA 516 ALLGRADES IMPACTTESTED

SA 333 GR.1

SA 350 GR.LF1 OR LF2

(-20) – (+4) SA 516 ALLGRADES OVER 1 IN.THICK IMPACTTESTED

SA 53(SEAMLESS) OR

SA 106

BOLTS: SA 193GR.B7

NUTS: SA 194GR.2H(+5) – (+32) SA 516 ALL

GRADES OVER 1 IN.THICK IMPACTTESTED

Material Selection for Temperature (Continued…)

SERVICETEMPERATURE (°F) PLATE PIPE FORGING PRESSURE

BOLTING

INTERMEDIATE

TEMP

(+33) – (+60)

SA 285 GR.C, ¾ IN.THK. MAX.SA 515 GR.55, 60,65, 1.5IN. THK. MAX.SA 516 ALLGRADES, ALL THK.

SA 53 (SEAMLESS) OR SA

106

SA 181 GR.IOR II

SA 105 GR.IOR 11

Bolts: SA 193 gr.B7

Nuts: SA 194 gr.2H

(+61) – (+775)

SA 285 GR.C, ¾ IN.THK. MAX.SA 515 GR.55, 60,65, 1.5IN. THK. MAX.SA 516 ALLGRADES, ALL THK.SA 204 GR.B ALL

Material Selection for Temperature (Continued…)

SERVICETEMPERATURE (°F)

PLATE PIPE FORGING PRESSUREBOLTING

ELEVATED

TEMPERATURE

(+776) – (+875) SA 204 GR.B OR C SA 335 GR.P1 SA 182GR.F1

BOLTS: SA 193GR.L7

NUTS: SA 194GR.2H

(+876) – (+1000) SA 387 GR.11 CL1SA 387 GR.12 CL.1

SA 335 P11SA 335 P12

SA 182 GR.F11SA 182 GR.F12

(+1000)– (+1100) SA 387 GR.22 CL1 SA 335 P22SA 182 GR.22

SA 193 GR.B5SA 194 GR.3

(+1100)– (+1500) SA 240 TYPES 304,316, 321, 347,347PREFERED

SA 312 TYPES304H, 316H, 312,

347H

SA 182GRADES

304H, 316H,321H, 347H

SA 193 GR.B8SA 194 GR.8

ABOVE +1500 TYPE 310STAINLESSINCOLOY

GROUPING OF MATERIALS

Base Metal TypeP1 : Carbon SteelP3, P4,P5 : Alloy SteelP6, P7 : Ferritic & Martensitic SteelP8 : Austenitic Stainless SteelP9 : Nickel SteelP10, P11 : Quenched & Tempered Steel

MATERIAL AND ITS SPECIFICATIONS

DESCRIPTION CS AS SS DSS

PIPE A 106 GR B A 335 GR P11 A 312 TP 316 A 790 UNS S31803

BW FITTINGS A 234 GR WPB A 234 GR WP 11 A 403 WP 316 A 815 UNS S 31803

FORGEDFLANGES/FITTINGS

A 105 A 182 GR F11 A 182 GR F 316 A 182 GR F 51UNS S 31803

FASTNERS A 193 GR B7/A 194 GR 2H

A 193 GR B16/A 194 GR 2H

A 193 GR B7M/A 194 GR 2HM

A 453 GR 660 CL A

PLATES A 516 GR 70 A 387 GR 11 A 240 GR 316 A 240 UNS S 31803