PRESSURE EQUIPMENT ENGINEERING SERVICES, INC.

Transcription

1 PRESSURE EQUIPMENT ENGINEERING SERVICES, INC. 402 WILD PEACH PLACE MISSOURI CITY, TX TEL. : (281) FAX : (281) Bharat@peesi.com EVALUATION OF THE VESSEL TO CALCULATE THE MINIMUM RETIREMENT THICKNESS VALUES FOR VARIOUS COMPONENTS OF THE VESSEL AND TO RE-RATE THE VESSEL TO A HIGHER TEMPERATURE PROBLEM DESCRIPTION: The current design conditions for the carbon steel vessel were F. It was requested to rerate the vessel to a possible higher temperature of 820 F. The engineering analysis and fitness-for-service evaluation of the vessel was required to see if the vessel can be qualified for F operation. Also, it was required to calculate the minimum retirement thickness values based on the re-rated design conditions. RESULTS: The vessel was analyzed using the Pressure vessel design and analysis software COMPRESS. It should be noted that the vessel has Class 150 and Class 300 flanges. The Carbon steel Class 150 flanges are not rated for F. Hence, the temperature rating of F could not be achieved for this vessel. However, the vessel was found to be suitable for F and it has been rated for these conditions. The re-rated design temperature was acceptable for the operation of the vessel. The new recommended minimum retirement thickness values were based on the re-rated MAWP condition of F. It was also determined that with the new retirement thickness values, the vessel had enough safe and useful life for continued operation for next 3-4 years.

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3 Pressure Summary Pressure Summary Pressure Summary for Chamber bounded by Bottom Head - Hemispherical and Top Head - Ellipsoidal Identifier T Design ( F) MAWP ( psi) MAP ( psi) MDMT ( F) MDMT Rating Exemption Corrosion Allowance Impact Test Top Head - Ellipsoidal Note 1 Straight Flange on Top Head - Ellipsoidal Note 2 Shell - Cylindrical Note 3 Bottom Head - Hemispherical Note 4 A - 12" Dia. (A) N/I Note 5 AL - 1-1/2" (AL) N/I Note 5 B - 3" Dia. (B) N/I Note 5 BL - 1-1/2" (BL) N/I Note 5 C - 6" Dia. (C) N/I -5.5 Note 6; Pad note 7 CL - 1-1/2" (CL) N/I Note 5 D - 4" Dia. (D) N/I -7.9 Note 8; Pad note 9 DL - 1-1/2" (DL) N/I Note 5 E - 6" Dia. (E) N/I Note 5; Pad note 10 EL - 2" Dia. (EL) N/I Note 5 F - 10" Dia. (F) N/I -7.2 Note 11; Pad note 12 Flange for F Note 13 Bolted Cover for F Note 14 G - 2" (G) N/I Note 5 GL - 2" Dia. (GL) N/I Note 5 file:///c /Compress-Temp/PresSum6E790E74.html (1 of 2) [8/20/2003 1:53:56 PM]

4 Pressure Summary H - 2" (H) N/I Note 5 HL - 2" (HL) N/I Note 5 J - 4" Dia. (J) N/I -7.9 Note 8; Pad note 15 Manway MH1-24" Dia. (MH1) N/I -7.2 Note 16; Pad note 12 Flange for MH Note 17 Bolted Cover for MH Note 18 Manway MH2-72" Dia. (MH2) N/I 0.0 Note 19; Pad note 20 Flange for MH Note 21 Chamber design MDMT is F Chamber rated MDMT is 1.08 F Chamber MAWP hot & corroded is F Chamber MAP cold & new is F This pressure chamber is not designed for external pressure. Design notes are available on the Settings Summary page. file:///c /Compress-Temp/PresSum6E790E74.html (2 of 2) [8/20/2003 1:53:56 PM]

5 Thickness Summary Thickness Summary Component Identifier Material Diameter Length Nominal t Design t Joint E Load Top Head - Ellipsoidal OD * Internal Straight Flange on Top Head - Ellipsoidal OD Internal Shell - Cylindrical OD Internal Bottom Head - Hemispherical OD * Internal Support Skirt # OD Wind Support Skirt # / OD Wind Nominal t: Vessel wall nominal thickness Design t: Required vessel thickness due to governing loading + corrosion Joint E: Longitudinal seam joint efficiency * Head minimum thickness after forming Load internal: Circumferential stress due to internal pressure governs external: External pressure governs Wind: Combined longitudinal stress of pressure + weight + wind governs Seismic: Combined longitudinal stress of pressure + weight + seismic governs file:///c /Compress-Temp/ThkHist1F1CE2C9.html [8/20/2003 1:53:56 PM]

6 Summary Summary mark OD t n Req t n A 1? A 2? Shell Nom t Design t User t Reinforcement Pad Width t pad Corr A a /A r (%) A Yes Yes * N/A N/A N/A Exempt AL Yes Yes N/A N/A N/A Exempt B Yes Yes N/A N/A BL Yes Yes N/A N/A N/A Exempt C Yes Yes CL Yes Yes N/A N/A N/A Exempt D Yes Yes DL Yes Yes N/A N/A N/A Exempt E Yes Yes * EL Yes Yes N/A N/A N/A Exempt F Yes Yes * G Yes Yes N/A N/A N/A Exempt GL Yes Yes N/A N/A N/A Exempt H Yes Yes * N/A N/A N/A Exempt HL Yes Yes N/A N/A N/A Exempt J Yes Yes MH Yes Yes * MH Yes Yes * t n : thickness Req t n : thickness required per UG-45/UG-16 Nom t: Vessel wall thickness Design t: Required vessel wall thickness due to pressure + corrosion allowance per UG-37 User t: Local vessel wall thickness (near opening) file:///c /Compress-Temp/NozSum3425DBAD.html (1 of 2) [8/20/2003 1:53:55 PM]

7 Summary A a : Area available per UG-37, governing condition A r : Area required per UG-37, governing condition Corr: Corrosion allowance on nozzle wall * Head minimum thickness after forming file:///c /Compress-Temp/NozSum3425DBAD.html (2 of 2) [8/20/2003 1:53:55 PM]

8 Schedule Schedule mark Service Size Materials Impact Norm Fine Grain Pad Impact Norm Fine Grain Flange A A - 12" Dia IDx AL AL - 1-1/2" 2.12 B B - 3" Dia IDx # BL BL - 1-1/2" 2.12 C C - 6" Dia # CL CL - 1-1/2" 2.12 D D - 4" Dia IDx # DL DL - 1-1/2" 2.12 file:///c /Compress-Temp/NozSch0F3A2451.html (1 of 2) [8/20/2003 1:53:55 PM]

9 Schedule E E - 6" Dia EL EL - 2" Dia IDx0.12 F F - 10" Dia IDx App 2 G G - 2" 2.36 IDx0.35 GL GL - 2" Dia IDx0.12 H H - 2" 2.36 IDx0.35 HL HL - 2" 2.36 IDx0.35 J J - 4" Dia IDx MH1 Manway MH1-24" Dia IDx App 2 MH2 Manway MH2-72" Dia IDx App 2 file:///c /Compress-Temp/NozSch0F3A2451.html (2 of 2) [8/20/2003 1:53:55 PM]