DILLINGER PRESSURE VESSEL COLLOQUIUM - · PDF fileDILLINGER PRESSURE VESSEL COLLOQUIUM DILLINGER HÜTTE GTS 16-17 September 2009 Fabrication of heavy wall reactors made in

DILLINGER PRESSURE VESSEL COLLOQUIUM

DILLINGER HÜTTE GTS

16-17 September 2009

Fabrication of heavy wall reactors made in CrMo(V) plates

Giacomo Fossataro(Walter Tosto SpA)

Walter Tosto SpA was founded in 1960 by Mr. Walter Tosto

DILLINGER PRESSURE VESSEL COLLOQUIUM 16-17 September 2009


1960 2009

First steps of company activities Nowdays, Company awarded with “INNOVATION PRIZE 2009”by The President Of the Italian Republic G. Napolitano

Walter Tosto SpA is located in the central part of Italy with shops in Chieti Scaloand in the port of Ortona



Production range covers the most critical components of a petrochemical plant such as Reactors, HP heat exchangers and Process Columns using the most

advanced and sophisticated steels






Case Study: fabrication of a CrMoV reactor


500 MTTOTAL WEIGHT

ASME VIII div.1/PEDDESIGN CODES

150 mmSHELL THICKNESS

4500 mmINTERNAL DIAMETER

-25,2°CMINIMUM DESIGN METAL TEMPERATURE

450°CDESIGN TEMPERATURE

92 bargINTERNAL DESIGN PRESSURE

REACTOR DATA



Courtesy of Axens



Adopded materials:

- Shell by plate in SA 542 D Cl 4a- Heads by plate in SA 542 D Cl 4a- Shell course with catalyst grid support ring by forging in SA 336 Gr F22V-All materials (including consumables) are procured in compliance with the most stringent market requirements, including both API 934 A and Axens Specificationfor chemistry limitation (ultra clean steel with very low level of tramp elements)


1042,14Actual Values

<= 15<=100Requested

X-barJ-factor


-22.5°C< 10°C

SAW (Tandem)Step CoolingTest

at 1/2 thk. WMV Tr 55 + 3 (V’Tr55-

VTr55)

N/mm2N/mm2

539T.S. >509

SAW (Tandem)HOT Tensile at 1/2 thk.

[At +454°C]

N/mm2N/mm2

465Y.S. >345SAW (Tandem)

HOT Tensile at 1/2 thk.[At +454°C]

N/mm2N/mm2N/mm2N/mm2

NW198÷205

HV10

< 248 HV10

NW217÷221H

V10

< 248 HV10NW

135÷170J

Min >48J

Avg >55J

NW162÷174

J

Min >48J

Avg >55J

619 ÷ 628T.S. 585

÷ 760634 ÷659

T.S. 585 ÷ 760SAW (Tandem)

at 1/2 thk.


HAZ192÷204

HV10

< 248 HV10

HAZ188÷216H

V10

< 248 HV10HAZ

244÷250J

Min >48J

Avg >55J

HAZ139÷194

J

Min >48J

Avg >55J

497÷513Y.S. >415548÷583

Y.S. >415SAW (Tandem)

at 1/2 thk. (A.W.M.)

ObtainedRequiredObtainedRequiredObtainedRequiredObtainedRequiredObtaineRequiredObtaineRequired

Hardness Test PWHT max (710°C

x 26h)

Hardness Test PWHT min (710°C x

8h)

Impact test PWHT max (710°C x 26h)

[At -30°C]

Impact test PWHT min (710°C x 8h)

[At -30°C]

Tensile Test PWHT max

(710°C x 26h)[At +20°C]

Tensile Test PWHT min

(710°C x 8h)[At +20°C]

Welding Process

Adopted welding process with some test results



-27.5°C< 10°C

SMAWStep CoolingTest

at 1/2 thk. WMV Tr 55 + 3 (V’Tr55-

VTr55)

N/mm2N/mm2

523T.S. > 509SMAW

HOT Tensile at 1/2 thk.[At +454°C]

N/mm2N/mm2

442Y.S. > 345SMAWHOT Tensile at 1/2 thk.

[At +454°C]


NW193÷199

HV10

< 248 HV10

NW200÷208H

V10

< 248 HV10

NW102÷117

J

Min >48J

Avg >55J

NW126÷149

J

Min >48J

Avg >55J

624 ÷ 639T.S. 585 ÷

760639 ÷ 660T.S. 585 ÷

760SMAWat 1/2 thk.

N/mm2N/mm2

N/mm2N/mm2

HAZ191÷200

HV10

< 248 HV10

HAZ187÷213H

V10

< 248 HV10

HAZ170÷194

J

Min >48J

Avg >55J

HAZ189÷211

J

Min >48J

Avg >55J

502÷516Y.S. > 415552÷591Y.S. > 415SMAW

at 1/2 thk. (A.W.M.)

ObtainedRequiredObtainedRequiredObtainedRequiredObtainedRequiredObtainedRequiredObtainedRequired

Hardness Test PWHT max (710°C

x 26h)

Hardness Test PWHT min (710°C x

8h)

Impact test PWHT max (710°C x 26h)

[At -30°C]

Impact test PWHT min (710°C x 8h)

[At -30°C]

Tensile Test PWHT max

(710°C x 26h)[At +20°C]

Tensile Test PWHT min

(710°C x 8h)[At +20°C]

Welding Process

Adopted welding process with some test results



A) Longitudinal welds

B) Nozzles and heads welds

C) Circumferential

Typical Heat Treatment Sequence

x 8h710°C (±5°)PWHT

x 6h650°CISR

x 6h350°CDHT

Summary of adopted heat treatments



- Hot forming of petals at 950°C

- Quenching & tempering of petalsaccording to mill recommendation

- Warm calibration of petals (at 250-300°C)

- Fit-up and SAW welding followed by ISR

- Machining of circumferential bevel

- Fit-up and welding of nozzles followed by ISR

HEADS FABRICATION



- Warm rolling of plates (at 350-400°C)

- Fit-up & SAW welding of longitudinal seamfollowed by ISR

- Machining of circumferential bevel

- Fit-up and welding of nozzles followed by ISR

SHELL COURSES FABRICATION



- Weld overlay by double heads ESW process type 347

FABRICATION OF SECTIONS (3 courser or 2 courses + head)

- Circumferential fit-up and SAW weldingfollowed by DHT



Automatic system of pre-heat/interpass management



“Drying and feeding fluxsystem designed and manufactured in-house.”



- Assembly and circular welding of main sections, followed by DHT

REACTOR COMPLETION

- Assembly and welding of external & internal appurtenances



Main Non Destructive Tests

PT - UTPT – UT - FERRITEOverlay

MT – TOFD - PHASED ARRAYMT – TOFD - PHASED ARRAYMT – TOFD - PHASED ARRAYNozzles welding

MT - TOFD - MANUAL U.T.MT - TOFD - MANUAL U.T.MT - TOFD - MANUAL U.T.Circumferentialwelding

MT - TOFD - MANUAL U.T.MT - TOFD - MANUAL U.T.MT - TOFD - MANUAL U.T.Longitudinal welding

AFTER HYDRO TESTAFTER PWHTBEFORE PWHT



– Rejected except if classified as another type of defect and passing ASME Code requirements.

1) Greater than 20% DAC -Reject

2) 10-20% DAC- Investigate and Characterize

RejectionCriteria

Primary objective is to determine if indication is planar and transverse.Look for >9 dB difference between the 70 and 60 degree scans (45 and 60 degree for depths greater than 120 mm). If > 9db (Hdmax-Hdmin) then classify as planar. Compare maximum signal obtained from transverse and parallel directions with thesame probe that produced the maximum signal (Figure 4) if the difference is >9 dB, the defect can be considered transverse.

Based on EN1713 (except no minimum amplitude and no echodynamic evaluation)

FlawCharacterization

Both directions along weldScanningDirection

Scanning for transverse flaws or “A-scan”, however this terminology is not consistent worldwide.Along ground weldScanning

Location

+ 14 dB above reference levelScanningSensitivity

Holes at multiple depths and some EDM notches are typically included.

3 mm side drilled holes (DAC set-up)

CalibrationReference

Multiple probes are used to “cover” the near and far zones:•70 degrees covers about 10-100 mm,•60 degrees covers about 50-150, and•45 degrees covers the deeper areas.

70 (primary detection angle), 60 and possibly 45 degrees

ProbeAngles

Transducer frequency should be 4 MHz for near side examination and 2 MHz for depths greater than 100 mm.

2 to 4 MHz (focused if necessary to achieve adequate resolution at

maximum depths)

ProbeFrequency

Flush GroundSurface Condition of Welded Joint

CommentsRecommendation

Manual Shear Wave Procedure for Identifying Transverse Reheat Cracks



POST WELD HEAT TREATMENT

The whole reactor has been treated in furnace with target 710°C +/- 5°C.

During the soaking time the temperature range was between 707°C and 714°C


10x11x28,5 mt.Furnace Dimension


FINAL ACTIVITIES

- Assembling and welding of bottom nozzles and skirt + local PWHT

- NDTs after PWHT

- Hydrotest

- NDTs after Hydrotest

- Painting, cleaning, blanketing etc.



Conclusion

Some of the winning factors for a safe reactor fabrication

- Intensive training of all involved personnel- Special care in consumable management system- Reliable automatism in preheat/interpass continuous control- Development of appropriate welding procedures- “Locked” welding parameters in production and automatic continuous record of them- ISR furnace located inside the shop- Severity in NDTs (Specific training and qualification for the operators)- Reliable PWHT procedure, furnace & skilled personnel to guarantee precise temperature (+/-5°C)



Thank you for your attention


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DILLINGER PRESSURE VESSEL COLLOQUIUM - · PDF fileDILLINGER PRESSURE VESSEL COLLOQUIUM DILLINGER HÜTTE GTS 16-17 September 2009 Fabrication of heavy wall reactors made in