144-111-pi-cal-015_r1

Project No : 040176

PIPING FLEXIBILITY ANALYSIS

Client : Petro Canada

Project : De Ruyter Production Platform

Location : P11-b

Document number: 144-111-PI-CAL-015 Rev. no : R1 Page : 1 of 14


PIPING SYSTEM

SK-015

PREPARED FOR

By:Iv-Oil & Gas b.v

Rev. Description Date By Checked Appr’d by

R1 For DNV Comments / Approval 20-07-2005 G.F. Costoiu R. Tjin M. van Neck

Project No : 040176




Location : P11-b


Rev. Description Date By Checked Appr’d by

R1 For DNV Comments / Approval 20-07-2005 G.F. Costoiu R. Tjin M. van Neck

Project No : 040176




Location : P11-b


TABLE OF CONTENTS Page

INTRODUCTION................................................................................................................................................. 31.1 SCOPE OF WORK.............................................................................................................................. 31.2 APPLICABLE CODES......................................................................................................................... 31.3 REFERENCE DOCUMENTS..............................................................................................................3

2. SYSTEM DESIGN.......................................................................................................................................... 42.1 LINE DATA........................................................................................................................................... 42.2 CII CALCULATIONS............................................................................................................................ 42.3 LOAD CASES...................................................................................................................................... 52.3.1 DESIGN LOAD CASES........................................................................................................................ 52.3.2 NEN-3650 LOAD CASES.....................................................................................................................52.4 STRESSES.......................................................................................................................................... 62.4.1 ALLOWABLE STRESSES ASME B31.3..............................................................................................62.4.2 NEN-3650 CODE................................................................................................................................. 62.5 BLAST CALCULATIONS..................................................................................................................... 82.6 PIPE SUPPORTS................................................................................................................................ 92.7 FLANGE CONNECTIONS...................................................................................................................92.8 NOZZLE LOADS.................................................................................................................................. 9

3. STRESS ANALYSIS.................................................................................................................................... 103.1 COMPUTER MODEL......................................................................................................................... 103.2 HYDRODYNAMIC LOADS.................................................................................................................11

4. ANALYSIS RESULTS................................................................................................................................. 124.1 STRESSES........................................................................................................................................ 124.1.1 DESIGN CASES................................................................................................................................ 124.1.2 BLAST CASES................................................................................................................................... 134.2 FLANGES.......................................................................................................................................... 144.3 NOZZLE LOADS................................................................................................................................ 14

APPENDICES

APPENDIX 1 STRESS SKETCHES

APPENDIX 2 PIPE SUPPORT DETAILED DRAWINGS

APPENDIX 3 CONSTRUCTION ISOMETRICS

APPENDIX 4 MISCELLANEOUS CALCULATIONS

Appendix 4.A Flange Loads Summary

Appendix 4.B Wave Loads

APPENDIX 5 CAESAR II PRINTOUT

Project No : 040176




Location : P11-b


INTRODUCTION

1.1 SCOPE OF WORK

The purpose of this report is to demonstrate that piping system SK-015, part of De Ruyter topside piping, has inherent flexibility to accommodate displacements due to design conditions, without imposing any excessive loads on pipe supports and equipment nozzles. Furthermore the piping stress level has to satisfy the designated code.

1.2 APPLICABLE CODES

The governing code for piping design is:

ASME B31.3 Process Piping

For items not covered by the above-mentioned document, reference is made to the following codes and standards:

ASME VIII Rules for construction of pressure vessels, Division 1 and 2

ASME III Rules for Construction of Nuclear Facility Components, Division 1

ASME B16.5 Pipe Flanges and Flanged Fittings

WRC-107 Local stresses in Spherical and Cylindrical Shells due to External loadings

NEN-3650 Eisen voor Transportleidingsystemen

1.3 REFERENCE DOCUMENTS

144-002-PI-SPE-0002 Piping Classes Specifications

144-002-PI-SPE-0007 Plant Department Pipe Stress Design Criteria

144-111-PI-LST-0001 Plant Department Critical Line List

144-000-PR-LST-0001 Process Line List

144-000-ME-SPE-0004 Nozzle Loads on Equipment

144-002-HE-TNS-0007 Blast Design Strategy and Overpressures

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Location : P11-b

Document number: 144-111-PI-CAL-015 Rev. no : R1 Page : 5 of 14 2. SYSTEM DESIGN

2.1 LINE DATA

Functional design data, used for analysis, is summarised below:

Item/ Line No.

Pipe

Cla

ss

Cor

rosi

on

Allo

wan

ce

Des

ign

Pres

sure

Hyd

rote

st P

ress

ure

Max

imum

Des

ign

Tem

pera

ture

Min

imum

Des

ign

Tem

pera

ture

Ope

ratin

g Te

mp.

Med

ium

Den

sity

Flan

ge R

atin

g

Drawing Number

- mm barg barg °C °C °C Kg/m3 # -

16”-TO-220-009-A41-V A41 3 16 24 60 -11 45 850 150 220009-0301

16”-TO-220-032-A41-V A41 3 16 24 60 -11 50 850 150 220032-0301

16”-TO-220-010-A60-V A60 3 16 24.1 60 -11 50 850 150220010-0301/

0101

2”-TO-220-035-A60-V A60 3 16 24.1 60 -11 50 850 150 220035-0301

2”-CD-580-073-A41-V A41 3 10 15 100 -11 60 850 150 580073-0301

Note: Installation temperature assumed as -11°C throughout.

The wall thickness of the riser pipe (API 5L X52), used in the stress analysis, is 25.4 mm. This information has been provided by the fabrication yard (Heerema) and is not reflected in the drawings included in Appendix 3. However the fabrication drawings will include the above mentioned wall thickness, for the riser pipe.

2.2 CII CALCULATIONS

The following CII calculations have been performed:

SK-015-R2 : Design conditions (B31-3)

SK-015B-R2 : Blast loads up to N223 – fire wall

SK-015B1-R2 : Blast loads after N223 – fire wall

SK-015C-R2 : NEN-3650 code stress check

SK-015C1-R2 : NEN-3650 blast case – stress check

Project No : 040176




Location : P11-b


2.3 LOAD CASES

2.3.1 DESIGN LOAD CASES

The functional and environmental loads, used to generate the design load cases, comprise the following:

(W) Gravity load, due to self-weight of steel, contents and insulation.

(P1) Pressure load, due to design pressure.

(T1) Thermal load due to maximum design temperature (all piping).

(D1) Displacements at termination point 10.

(U1,2) Hydrodynamic loads. Loads are applied in +X for Case 1 and +Z for Case 2.

(WIN1..4) Wind loads based on 42m/s velocity at 10m (100 year - 3 sec’s gust). Loads are applied in +X for Case 1, -X for Case2, +Z for Case 3 and –Z for Case 4.

2.3.2 NEN-3650 LOAD CASES

The stress verification according NEN-3650 has been made by multiplying all loads with the applicable design factors. Further details are given in section 2.4.2, below.

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Location : P11-b


2.4 STRESSES

2.4.1 ALLOWABLE STRESSES ASME B31.3

The allowable stresses are in compliance with the criteria specified in ASME B31.3.

Material Max temp [ºC ]

Material Properties [N/ mm²]

Allowable stresses [N/mm²]

SMTS SMYS Sh Sa (EXP) Socc (OCC)

A333 Gr. 6 60 / 100 414 241138 207 183

Sustained Stress range Occasional

API 5L X52 60 455 358151.7 227.5 201.7

Sustained Stress range Occasional

Note : Stress range is based on a stress reduction factor (f) of 1.

2.4.2 NEN-3650 CODE

CALCULATED STRESSES

The calculated stresses (Sv), according NEN 3650, shall be determined either by Maximum Distortion Energy theory, or by Maximum Shear Stress theory. Considering the principal stresses S1, S2 and S3, the equivalent stresses are:

Sv = (S12 + S2

2 + S32 –S1S2 – S2S3 – S3S1) 0.5

Maximum value of: S1 – S2 ; S2 – S3 ; S3 – S1

The Yield Stress Criterion included in CAESAR II is calculated as per von Mises Octahedral Shear Stress Theory:

1/3 [ (S1 – S2)2 + (S2 – S3)2 + (S3 – S1)2] 0.5

The Octahedral Shear Stress determined in Caesar II, is identical to the NEN 3650 equivalent stress (based on Maximum Distortion Energy), provided the factor [20.5/3] is considered with regard to the allowable stress limit. The equivalent stress is calculated at 4 points along the axis normal to the plain of bending and the maximum value printed in the stress report.

In CAESAR II the principal stresses are determined as follows:

S1 = (SL + SH)/2 + [(SL - SH)/2)2 + 2]0.5

S2 = -P (Radial pressure stress at inside pipe) ; S2 = 0 (Radial pressure stress at outside pipe)

S3 = (SL + SH)/2 - [(SL - SH)/2)2 + 2]0.5

Where:

SL = Longitudinal stress due to loading component considered (weight, pressure, thermal expansion; wave or wind)

= Torsional shear stress

SH = Tangential (Hoop) pressure stress, calculated using Lame’s equation

SH = P ( ri2 + ri

2 • ro2 / r2) / ( ro

2 – ri2) with ri inner pipe radius and ro outer pipe radius.

Project No : 040176




Location : P11-b


STRESS LIMIT

The topside riser piping has been designed to satisfy requirements of NEN 3650, with respect to calculated stress. The stresses are calculated for the following case: Survival case (process design conditions combined with 100 year return environmental loads).

The stress limit (allowable) value is tabulated below:

Stress Formulation Stress Correction factor Allowable stress

Hoop Stress (Design Pressure) NA Re()

Equivalent Stress Sv1 (pm) 1 Re()

Equivalent Stress Sv2 (pm + pb) 1.5 Re()

Equivalent Stress Sv3 (pm + sm) 1.5 Re()

Equivalent Stress Sv4 (pm+pb+sm+sb) 1.5 Re()

Where:

pm primary membrane stress

pb primary bending stress.

sm secondary membrane stress.

sb secondary bending stress.

Re() yield stress at design temperature.

Re yield stress at ambient temperature.

For the riser flexibility analysis the primary and secondary bending stresses over the pipe cross section are considered membrane stress over the pipe wall, as the main portion of the bending stress is a constant (membrane type) stress over the pipe wall. Therefore the equivalent stresses considered for analysis are Sv1 and Sv3.

With respect to Caesar II load combinations and equivalent stresses Sv1 and Sv3 the following cases will be considered.

Equivalent stress

Stress type

CAESAR II Load Cases (for operating condition)

Allowable Stress

Notes

Sv1 Pm 1.5 P1+ 1.5 W + WIND1..4 1 x Re() Note1

Sv3 pm + sm 1.5 P1+ 1.25 T1 + 1.5 W + WIND1..4 1.5 x Re() Note 1

NOTE: 1.The environmental loads will be applied in 4 directions and therefore 4 Caesar II load cases will be created for this stress case.

ALLOWABLE STRESSES

The allowable stresses are in compliance with the criteria specified in NEN-3650.

Material Max temp [ºC ]Material Yield Strength at

temperature [N/ mm²]

Allowable stresses [N/mm²]

SV1 SV3

A333 Gr. 6 60 235235 352.5

(110.7) (166.2)

API 5L X52 60 347347 520.5

(163.5) (245.3)

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Note : The figures indicated in brackets ( ) are factored (multiplied with 2 0.5/3) values for direct comparison with CII calculated Von Mises Octahedral Shear Stress.

2.5 BLAST CALCULATIONS

The blast critical piping has been identified as per doc. no 144-002-HE-TNS-0007. The riser line 16”-TO-220-010-A60 is blast critical. Blast loads are applied as follows.

Calculation SK-015B: From N10 to N223 (fire wall) and the 2”line.

Calculation SK-015B1: From N223 to N272 deck penetration at El. +18.000.

Calculation SK-015C1: Stress verification using NEN 3650 design factors for functional loads. For simplification blast loads are applied between N10 and N272

Blast Load: 20 KN/m2

Shape factor: 0.9 (conservative approach resulting in approximately 20% safety margin).

The blast loads are generated using CII wind modeler. The loads are applied in four (4) directions as described in section 2.3, above. The environmental loads are not considered in blast calculations. Although line 2”-TO-220-035 is not blast critical, the pipe routing is included up to N670 to ensure the integrity of the NC ball valve. For blast calculations, the following load cases are used:

Load cases used in calculation SK-015B and SK-015B1. Definition of loads is as per paragraph 2.3.1 with exception of : (T1) Operating temperature(WIN1…4) Blast loads

Load cases used in calculation SK-015C1. Definition of loads is as per paragraph 2.3.1 with exception of : (T1) Operating temperature(WIN1…4) Blast loads

Project No : 040176




Location : P11-b


2.6 PIPE SUPPORTS

All loads on supports are summarised in the Pipe Stress Analysis Output.

The loads include the friction forces. In general a friction coefficient of 0.4 is taken into account for friction between steel surfaces. In special cases where PTFE-sliding pads may be applied a friction coefficient of 0.1 shall be taken into account. The pipe support detail drawings are included in Appendix 2. All pipe supports are designed for blast loads (calculation SK-015B and SK-015B1).

2.7 FLANGE CONNECTIONS

Flange connections are modelled in CAESAR II by anchoring together the rigid elements through a CNODE. This enables an easy check of the external loads using CII restraint output summary.

For B16.5 flange analysis, either of the following two methods has been used:

1. External loads acting on these connections are assessed using the ASME BPVC, Section VIII, Division 1, Appendix 2 in combination with Section III, subsection NC. Actual hub length is used.

2. External loads acting on these connections are assessed using the ASME Section III, Division 1, subsection NC-3658.3, ASME B16.5a Flanged Joints with High Strength Bolting, with yield stress at temperature, SY, substituted with B31.3 allowable stress, Sh.

Flange analysis is performed for maximum acting loads and calculations are performed for each flange size in the calculation.

2.8 NOZZLE LOADS

External loads acting on metering skid nozzle are compared against the allowable values stated in document 144-000-ME-SPE-0004 (Nozzle Loads on Equipment).

Project No : 040176




Location : P11-b

Document number: 144-111-PI-CAL-015 Rev. no : R1 Page : 11 of 14 3. STRESS ANALYSIS

3.1 COMPUTER MODELFinite element computer models are developed based on the stress isometric included in Appendix 1.

Pipe stress program CAESAR II version 4.50, developed and marketed by COADE Engineering Software has been used for the analysis of the piping systems. This software package is a widely accepted tool to perform comprehensive stress analysis of complex piping systems.

The global co-ordinate system used in the computer model is indicated on the stress isometrics. Small differences in dimensions between the piping isometrics and the calculations may occur, but have no significant effect on the analysis.

Line 2”-TO-220-035 and its continuation 2”-CD-580-073 have been included in this computer model to verify the integrity of the weldolet ( node 220) and of the line (up the ball valve, node 590). In particular the integrity for the blast case has been checked.

The pipe routing of this system is shown below:

N272 – Deck at El. +18

N223 – Fire wall

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Location : P11-b


3.2 HYDRODYNAMIC LOADS

ENVIRONMENTAL DATA

The environmental data listed below has been derived from the Basis of Design, document no. 144-000-PR-BOD-1001.

Water Level110 Year return

Value Units

Water Depth (from LAT) 33.5 m

Highest Astronomical Tide 2.5 m

Storm Surge 2.2 m

Maximum Water Level 38.2 m

Wave Wave Data

Omni-directional Maximum Height H [m] (1)

Associated Period T [sec]

100 year return 13.8 x 1.079 = 14.9 11.8

1 year return 10.0 x 1.079 = 10.8 10.1

Note: 1. The maximum wave heights have been multiplied by 1.079 to account for Subsea Storage Tank (SST) influence.

Current Current Data

Surface Value Units

100 year return 1.56 m/s

1 year return 1.34 m/s

WAVE LOADS

The water particle velocities due to wave and current are computed using Stokes 5 th wave theory. The forces to be considered are:

Inertia force

Drag force

The Morrison equations will be used to determine those forces at a moment of the wave cycle (defined by the phase angle). The maximum hydrodynamic forces are obtained at maximum particle velocity. These are found for zero degree wave phase angle at which the accelerations are equal to zero. For the flexibility calculations (Caesar II) the same phase angle, of zero degree, will be used at all elements (conservative approach).

Inertia Force: FI = CM • • D2 / 4 • a

Where: CM = mass coefficient = 1.6

D = total outside pipe diameter

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a = acceleration vector of the water particles

Drag Force: FD = CD • • 0.5 D • v2

Where: CD = drag coefficient = 0.65 x 1.102 = 0.72

v = velocity vector of the water particles

To take into account the influence of the Subsea Storage Tank the drag coefficient has been multiplied by a factor 1.102.

4. ANALYSIS RESULTS

4.1 STRESSES

The maximum calculated code stresses are summarized below and compared against code allowable values (B31.3 or NEN3650). For blast case the calculation method set in document no 144-002-PI-SPE-0007 was used. The calculated 3D stress intensities are compared with the minimum between the yield at operating temperature multiplied by 4/and 0.9 of the tensile strength.

4.1.1 DESIGN CASES

All stresses are found within the allowable limits.

Table 4.1.1.1 Maximum Sustained Stress (SK-015)

Case No. Node MaterialCode Stress

N/mm²

Allowable Stress

N/mm²

Ratio

7 78 A333 Gr.6 48.3 138 0.35

Table 4.1.1.2 Maximum Stress Range (SK-015)


N/mm²

Allowable Stress

N/mm²

Ratio

12 295 API 5L X52 16.9 227 0.07

Table 4.1.1.3 Maximum Occasional Stress – Wind effects (SK-015)


N/mm²

Allowable Stress

N/mm²

Ratio

11 78 A333 Gr.6 54.8 183 0.30

Table 4.1.1.4 NEN-3650 – Sv1 (SK-015C)

Case No. Node MaterialVM Stress

N/mm²

Allowable Stress

N/mm²

Ratio

9 225 (16”) API 5L X52 12.9 163.5 0.08

9 498 (2”) API 5L X52 19.2 163.5 0.11

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Location : P11-b


Table 4.1.1.5 NEN-3650 – Sv3 (SK-015C)


N/mm²

Allowable Stress

N/mm²

Ratio

10 295 (16”) API 5L X52 17.1 245.3 0.07

9 498 (2”) API 5L X52 24.9 245.3 0.10

4.1.2 BLAST CASES

This case is applicable for:

- Riser pipe, from node 150 to node 300.

- 2” branch, up to the ball valve at node 590 ( from 500 to 590).

All stresses are found within the allowable limits as summarized in the tables below. The maximum calculated 3D stress of 375.9 N/mm2 is found in 2” line at node 638 (beginning point of bend 640). Since this stress is higher than the allowable of 299 N/mm2, a possible failure at the 2” bend is noted. However this is no reason for concern since the stresses in the 2” line, between weldolet and ball valve are acceptable, and the ball valve at node 590 is normally closed. Therefore the integrity of the 16”riser pipe will not be affected.

Table 4.1.2.1 3D Stresses – Blast effects (SK-015B)

Case No./ Location

Node Material3D Stress

N/mm²

Allowable Stress

N/mm²

Ratio

9 269 (16”) API 5L X52 31.6 409 0.08

9 498 (2”) API 5L X52 240.7 409 0.59

Table 4.1.2.2 3D Stresses – Blast effects (SK-015B1)

Case No. Node Material3D Stress

N/mm²

Allowable Stress

N/mm²

Ratio

9 295 (16”) API 5L X52 41.8 409 0.10

9 498 (2”) API 5L X52 40.6 409 0.10

Table 4.1.2.3 NEN-3650 – Blast effects (SK-015C1)


N/mm²

Allowable Stress

N/mm² 1)

Ratio

9 225 (16”) API 5L X52 23.9 163.5 0.14

9 498 (2”) API 5L X52 113.3 163.5 0.69

Note: 1) Allowable stress for NEN blast case are assumed equal to allowable stress for design case Sv1 (no multiplication factors are used).

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Location : P11-b


4.2 FLANGES

The integrity of the ASME B16.5 flanges, under the maximum external loads, has been checked as outlined in section 2.7. The external loads are found to be acceptable. Detailed flange calculations and the summary have been included in Appendix 4 where required.

4.3 NOZZLE LOADS

The maximum external nozzle loads on TP2 of metering skid 901-XY-01 are listed below and compared with the allowable values stated in document 144-000-ME-SPE-0004 (Nozzle Loads on Equipment).

Note: Forces in [N] and moments in [Nm]

Table 4.3.1 Metering Skid 901-XY- 01 / TP1

Design Case – SK-015-R2

Size Calc. No. Node No.

Fx Fy Fz Mx My Mz

16”-150# SK-015 10 -2300 -16200 5600 -8600 1700 -750

Allowable values 11000 11000 10500 11500 10000 22000

The vertical force Fy exceeds the allowable value. The external loads are considered acceptable since the actual resultant force is smaller than the allowable resultant force.

FR = (Fx2 + Fy2 + Fz2)0.5 = 17300N < FRall = 18768N

Project no : 040176


Project title : De Ruyter Production Platform

Location : P11-b


Document number : 144-111-PI-CAL-050 Rev. no : R1

APPENDIX 1

STRESS SKETCHES

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APPENDIX 2

PIPE SUPPORT DETAILED DRAWINGS

Hold for update: 1-A-1-0466-A

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APPENDIX 3

CONSTRUCTION ISOMETRICS

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APPENDIX 4MISCELLANEOUS CALCULATIONS

APPENDIX 4.A Flange Calculations

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APPENDIX 4MISCELLANEOUS CALCULATIONS

APPENDIX 4.B Wave loads

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APPENDIX 5

CAESAR II PRINTOUT

144-111-pi-cal-015_r1

Documents

piping design

design cases

design load cases

design conditions

stress analysis

process piping

bwave loads appendix

blast design strategy