DILLINGER HDILLINGER HÜÜTTETTESYMPOSIUMSYMPOSIUM

SPECIFICATIONS FOR SPECIFICATIONS FOR PRESSURE VESSELS PRESSURE VESSELS -- THEIR THEIR TRENDS AND CHALLENGESTRENDS AND CHALLENGESFOCUS:FOCUS:HYDROHYDRO--PROCESSING REACTORS MADE PROCESSING REACTORS MADE FROM 2 ¼ Cr FROM 2 ¼ Cr –– 1Mo 1Mo –– V (Enhanced Steel)V (Enhanced Steel)

Radoslav Stefanovic Radoslav Stefanovic

Fluor Canada Ltd.Fluor Canada Ltd.Calgary, AlbertaCalgary, Alberta

Advanced Steels for Boilers & Pressure Vessels SymposiumAdvanced Steels for Boilers & Pressure Vessels SymposiumJune 21, 2005June 21, 2005

Calgary, Alberta, CanadaCalgary, Alberta, Canada®

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Introduction Introduction

TransportationTransportation

Field FabricationField Fabrication

LiftingLifting

Fatigue EvaluationFatigue Evaluation

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INTRODUCTIONINTRODUCTION

2 ¼ Cr 2 ¼ Cr --1Mo1Mo--V (enhanced steel) is used V (enhanced steel) is used extensively as material for elevated temperature extensively as material for elevated temperature and pressures hydroand pressures hydro--processing reactorsprocessing reactors

Temperatures 427 °C Temperatures 427 °C –– 482 °C482 °C

Pressures 18,600 kPa Pressures 18,600 kPa –– 19,300 kPa19,300 kPa

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INTRODUCTION (Cont.)INTRODUCTION (Cont.)

Why is it important to have Vanadium enhanced Why is it important to have Vanadium enhanced materials?materials?

High resistance against elevated temperature High resistance against elevated temperature hydrogen attackhydrogen attack

High strength at elevated temperature resulting High strength at elevated temperature resulting in reduction in reactor wall thickness and weight in reduction in reactor wall thickness and weight

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INTRODUCTION (Cont.)INTRODUCTION (Cont.)

637219162,716168,822173,748II

753260139,964144,790149,609I2 1/4 Cr - Mo - V

704247117,211150,995155,133II

895295103,421128,932133,069I2 1/4 Cr - 1 Mo

482 ºC454 ºC427 ºC

Weight(metric tons)

Thickness(mm)

@ design temperature

of 454 °C

Allowable stress in kPa @ design temperature

ASME VIIIDIVMaterial

Thickness & weight comparison for 2 ¼ Cr Thickness & weight comparison for 2 ¼ Cr –– Mo (conventional) vs. 2 ¼ Cr Mo (conventional) vs. 2 ¼ Cr –– Mo Mo –– V V (enhanced) steels (enhanced) steels

(inside diameter ID = 3660 mm , tangent to tangent T/T = 24000 m(inside diameter ID = 3660 mm , tangent to tangent T/T = 24000 mm)m)

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Introduction (Cont.)Introduction (Cont.)

Use of advanced (enhanced) steels reduces: Transportation cost (can be significant and as high as 80% of the reactor cost)Requirement for field fabrication (saving in cost and project duration)Lifting cost

Total cost

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TRANSPORTATIONTRANSPORTATION

Hydroprocessing Reactors are usually fabricated in Japan or ItalyLand vs. Sea transportation challenges

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TRANSPORTATION (Cont.)TRANSPORTATION (Cont.)

The biggest challenge to bring vessels to Alberta, Canada is rail transportation

Restriction in shipping envelope

Restriction in weight per axle

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TRANSPORTATION (Cont.)TRANSPORTATION (Cont.)

Possible options for rail transportation

Conventional shipping in one piece

Shipping by Schnabel Car (Owned by Westinghouse, USA)

Conventional shipping in two or more pieces

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TRANSPORTATION (Cont.)TRANSPORTATION (Cont.)

Maximum weight per axle is 29.5 metric tons

Rail Transportation restrictions for bringing vessels to Rail Transportation restrictions for bringing vessels to Alberta, CanadaAlberta, Canada

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TRANSPORTATION TRANSPORTATION (Conventional shipping in one piece)(Conventional shipping in one piece)

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TRANSPORTATION (Schnabel Car)TRANSPORTATION (Schnabel Car)Largest railroad car in the worldCapacity to transport load up to 880 metric tons (also a function of length)

Courtesy of Westinghouse

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TRANPORTATION (Schnabel Car )TRANPORTATION (Schnabel Car )

Load is suspended between two halves of the carLow CofG allows the transport of heavier loads

Courtesy of Westinghouse

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TRANSPORTATION (Schnabel Car)TRANSPORTATION (Schnabel Car)Allows transportation of bigger reactors

Courtesy of Westinghouse

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TRANSPORTATION (Schnabel Car)TRANSPORTATION (Schnabel Car)

Use of Hydraulic system allows equalization of load on Use of Hydraulic system allows equalization of load on the rails and prevents any overturning situationthe rails and prevents any overturning situation

Courtesy of Westinghouse

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TRANSPORTATION (Schnabel Car)TRANSPORTATION (Schnabel Car)

Reactor is exposed to high compression and buckling loads approximately of 2,500 metric tons

The shell and top nozzle can take this loads because of size and thickness of the reactors

Skirt is the most critical component because it is thinner and lower part is manufactured from carbon steel

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TRANSPORTATION (Schnabel Car)TRANSPORTATION (Schnabel Car)

F4 F8

F7

F2

F5

F1

F6

FEA Skirt Model

F9 F9

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TRANSPORTATION (Schnabel Car)TRANSPORTATION (Schnabel Car)

Displacement

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TRANSPORTATION (Schnabel Car)TRANSPORTATION (Schnabel Car)

Stress in Skirt

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FIELD FABRICATIONFIELD FABRICATION

When size and weight of the vessel prohibits the transport in one piece, reactor is transported in two or more pieces and final fabrication is done on site

Fabrication of multi-piece reactors can be performed in horizontal or vertical position

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FIELD FABRICATION (Cont.)FIELD FABRICATION (Cont.)

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FIELD FABRICATION (Cont.)FIELD FABRICATION (Cont.)

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FIELD FABRICATION (Cont.)FIELD FABRICATION (Cont.)

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FIELD FABRICATION (Cont.)FIELD FABRICATION (Cont.)

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LIFTINGLIFTING

Lifting Limitations

Crane capacity

Access for lifting

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LIFTING (Cont.)LIFTING (Cont.)

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LIFTING (Cont.)LIFTING (Cont.)

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LIFTING (Cont.)LIFTING (Cont.)

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FATIGUE EVALUATIONFATIGUE EVALUATION

The rules to determine need for fatigue analysis are The rules to determine need for fatigue analysis are provided in ASME Section VIII Div. 2; Para. ADprovided in ASME Section VIII Div. 2; Para. AD--160160

AD-160.1 Operating experienceLicensor and owner experience with this material is limited and it is difficult to justify applying this paragraph

AD-160.2 & 3 are applicable for materials having a specified tensile strength not exceeding 552 MPa

2 ¼ Cr - 1Mo - V minimal tensile strength is 586 MPa and Code Case 2306 should be applied

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FATIGUE EVALUATION (Cont.)FATIGUE EVALUATION (Cont.)

To find the actual number of cycles, a detail thermal To find the actual number of cycles, a detail thermal and pressure screening shall be performed for:and pressure screening shall be performed for:

Commissioning

Normal Start-up

Normal Shut-down

Emergency conditions

Steady state operation

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FATIGUE EVALUATION (Cont.)FATIGUE EVALUATION (Cont.)

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FATIGUE EVALUATION (Cont.)FATIGUE EVALUATION (Cont.)

ASME Section VIII div 2; Appendix 5 provides ASME Section VIII div 2; Appendix 5 provides fatigue curves valid only for temperatures not fatigue curves valid only for temperatures not exceeding 371 exceeding 371 °C.°C.

The High Pressure Gas Safety Institute of Japan The High Pressure Gas Safety Institute of Japan and Kobe Steel, Ltd. published fatigue curves in and Kobe Steel, Ltd. published fatigue curves in PVPPVP--Vol 473 (2004). Load and strain controlled Vol 473 (2004). Load and strain controlled fatigue tests were conducted over the range from fatigue tests were conducted over the range from room temperature to 500 °C. Specimens were room temperature to 500 °C. Specimens were made from forged rings.made from forged rings.

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USER DESIGN SPECIFICATION USER DESIGN SPECIFICATION PREPARATION (Cont.)PREPARATION (Cont.)

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CONCLUSIONCONCLUSION

TransportationTransportation

Field FabricationField Fabrication

LiftingLifting

Fatigue EvaluationFatigue Evaluation