Abu Dhabi Oil Refining CompanyDGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS DGS-MD-001 Rev-1 VESSEL DESIGN BASIS Amendment History No Date Amendment Description Proposed Approved Incorporated DGS History 1 April 2009 DGS-MD-001-Rev-1 Base Reference –Project 5578 TH/DDC QAM / MAY 0 March 2006 DGS-MD-001-Rev-0 Previous Project / Lessons Learnt Incorporated TH/DDC ETSDM / EPDM No Date Description Source Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Reviewed Initials Approved Page 1 of 17 .............................................9 10..............................................................................................9 10..........................................................................................................6 3...........................................4 CORROSION ALLOWANCE ...10 10........................6 3.........................12 10...............................................7 MATERIALS...............................18 PAINTING .....................................................................0 QUALITY ASSURANCE/QUALITY CONTROL ...................................................2 DESIGN TEMPERATURE ................................................................................................ 11 10..................................1 DESIGN PRESSURE ...........................................................................................................17 NOZZLES ...............................................................................13 10...............................................................................................................................................................................................15 MANWAYS AND HANDHOLES.............7 4...............................0 DESIGN CRITERIA ...............................5 POSTWELD HEAT TREATMENT....10 HYDROSTATIC TEST ...........2 PROJECT STANDARD DRAWINGS........................10 10....................................17 1...........8 EARTHQUAKE LOAD ..........12 10.................... PLATFORMS AND DAVITS.......................1 PROJECT STANDARD SPECIFICATIONS..............14 HEADS ....16 LADDERS............4 2..................................................................................................0 HANDLING ...........13 SUPPORTS AND ANCHOR BOLTS.....................................................................4 1...................................15 10.....................................................................................................3 DEFINITIONS .........................................9 9..........................................................11 INSULATION ................................9 6............13 10......9 10......14 10..........................................1 INTRODUCTION ............ 11 10..........................0 REFERENCE DOCUMENTS .....0 CODES AND STANDARDS ........................................................14 10.................................................................................................................................................0 DOCUMENT PRECEDENCE .......................................0 SUBCONTRACTORS/SUBVENDORS ...........................3 MINIMUM THICKNESS ................................................................................................0 Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 2 of 17 .....14 10..........................13 10.................9 7......14 10...........................................................................................................15 10...........................8 5.......Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS TABLE OF CONTENTS GENERAL ...................0 SPECIFICATION DEVIATION/CONCESSION CONTROL ........................................................................................................................................4 1.............6 RADIOGRAPHIC WELD INSPECTION............................................................2 PURPOSE ............14 10.......................................................9 WIND LOAD .............................4 3.................................0 DOCUMENTATION .......................................................................9 8...................................................................................................16 ADDENDUM SHEET .............................................................4 1..........................................................................12 VESSEL FIREPROOFING ................ ADRD ------------------------------ DGS Discipline Committee Member. E&PD Quazi Abdul Matin (QAM) Engineering & Projects Division Manager. RRD ------------------------------ DGS Discipline Committee Member Leader. E&PD Mohamed Al Yabhouni (MAY) Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 3 of 17 .Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS List of Authorized Signatures/ Initials DGS Discipline Committee Member. E&PD Taha Hussein (TH) Engineering & Technical Services Manager. it refers to an authorization to use. SHOULD – Denotes an action or requirement which is not mandatory but which is strongly recommended. The requirements for the fabrication and inspection of pressure vessels are covered in specifications referenced below. Specific requirements for any particular vessel will be furnished on the Project vessel Data Sheets/drawings. components or equipment already in progress or completely manufactured but which does not meet or comply with COMPANY requirements. recondition. Project vessel Data Sheets/drawings shall specify the applicable code. stamping requirement. design data. The codes and standards listed below shall be used as referenced in this specification or on Project vessel Data Sheets/drawings. repair. 1.Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS 1.0 CODES AND STANDARDS It shall be the CONTRACTOR’S responsibility to be. reclaim. to the extent specified herein. or to become. the following definitions shall apply: CONCESSION REQUEST — A deviation requested by the SUBCONTRACTOR or VENDOR. and spheres. 1. The following Codes and Standards. knowledgeable of the requirements of the referenced Codes and Standards. form a part of this specification.2 PURPOSE This specification is intended for use in design and construction of pressure vessels.0 GENERAL 1. usually after receiving the contract package or purchase order. SHALL — Indicates a mandatory requirement. specifications. American Society of Mechanical Engineers/American National Standards Institute (ASME): Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 4 of 17 . A CONCESSION REQUEST is subject to COMPANY approval. or release materials.3 DEFINITIONS For the purposes of this Specification.1 INTRODUCTION This specification governs the general requirements for the mechanical design of all pressure and vacuum vessels. 2. and reference drawings. Often. The latest edition in force shall apply. and C Material Specifications Section II Parts D Material Properties Section V Nondestructive Examination Section VIII Division 1 Pressure Vessels Section VIII Division 2 Pressure Vessels Alternative Rules Section IX Welding and Brazing Qualifications Other Codes: ASCE Code American Society of Civil Engineer Code UBC Uniform Building Code International Organization for Standardization (ISO) ISO 9001 .Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS ASME B1.5 Steel Pipe Flanges and Flanged Fittings ASME B16. Waviness. 107 Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 5 of 17 . and Lay) ASME Boiler and Pressure Vessel Code: Section II Parts A.1 Unified Screw Threads ASME B16.3 Chemical Plant and Petroleum Refinery Piping ASME B46.1 Surface Texture (Surface Roughness. B.2000 Quality Management System Requirements ISO 9004 .47 Large Diameter Steel Flanges. NPS 26″ through NPS 60” ASME B31.2000 Quality Management Guidelines for Performance Improvement System ISO 19011 Guidelines for Quality and/or Environmental System Auditing Welding Research Council (WRC) WRC Bulletin 107 Local stress in Spherical and Cylindrical Shells due to External Loadings WRC Bulletin 297 Local stress in Spherical and Cylindrical Shells due to External Loadings – Supplement to WRC Bulletin No. Nickel and Nickel Alloy DGS-MD-005 Pressure Vessels .0 REFERENCE DOCUMENTS The following reference documents.Supplement for Alloy Lined Steel DGS-MD-006 Vessel Trays – General DGS-MD-007 Requirements for Manufacturing Data Report for Pressure Vessels DGS-MD-008 Ladders and Platforms .Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS 3.Supplement for Low Temperature Services DGS-MN-001 Insulation DGS-MU-002 Preservation and Export Packing DGS-MU-013 Criticality Rating System DGS-MU-014 Minimum Shop Inspection and Certification Requirements DGS-MW-001 Welding.Pressure Vessels DGS-MD-011 Pressure Vessels . Ferritic and Duplex High Alloy Steel. NDE and Prevention of Brittle Fracture of Pressure Vessels and Heat Exchangers DGS-MW-004 Materials and Fabrication Requirements for Carbon Steel Piping and Equipment in Severe Services DGS-MW-005 Materials and Fabrication Requirements for Cr-Mo Alloy Steel High Pressure Equipment DGS-MW-006 Positive Materials Identification of Equipment and Piping DGS-MX-001 Painting DGS-MX-002 Galvanizing Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 6 of 17 . to the extent specified herein. 3.1 PROJECT STANDARD SPECIFICATIONS Project Standard specifications listed below shall be used as referenced herein or on Project vessel Data Sheets/drawings: DGS-CU-002 Structural Engineering Criteria DGS-MD-002 Pressure Vessels – General DGS-MD-004 Pressure Vessels – Supplement for Austenitic. form a part of this specification. 2 Technical Specification for Piping Systems PROJECT STANDARD DRAWINGS Project Standard drawings listed below shall be used as referenced herein or on Project vessel Data Sheets/drawings: STD-MD-00011 Supports for Hot Insulation and Fireproofing STD-MD-00012 Saddle Details for Horizontal Vessels STD-MD-00013 Vertical Vessel Skirt Base Details STD-MD-00014 Skirts. Overlay Welded and Clad Steel Nozzles STD-MD-00023 Internal Baffle Hatchway Cover Details STD-MD-00024 Nameplate with Bracket for Vessel and Heat Exchange Equipment STD-MD-00025 Internal Ladder Rung Details STD-MD-00026 Typical Details of Demisters STD-MD-00027 Typical Details of Demister Attachments STD-MD-00028 Typical Details of Demister Supports STD-MD-00029 Davit for Column. Cylindrical and Conical STD-MD-00015 Support Legs and Base Plated Details STD-MD-00016 Vortex Breakers STD-MD-00017 Bolting for Non-Standard Flanges with Unified Inch Screw Threads STD-MD-00018 Stilling Well for Displacement-Type Level Instruments STD-MD-00019 Davit for ANSI or BS Flanges Nom. General Arrangement & Typical Details STD-MD-00030 Vessel Piping Support and Guide Details STD-MD-00031 Typical Vessel Ladder and Platforms.Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS DGS-PU-003 3. Size 12-24 Inch Inclusive Classes 150-600 Inclusive STD-MD-00020 Nozzles to Apparatus STD-MD-00022 Typical Details of Bush Lined. Sheet 1 Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 7 of 17 . Sheet 2 STD-MD-00048 Feed Nozzle Details. the Codes and Standards and any other specifications noted herein. Sheet 3 STD-MD-00038 Obstruction Lights for Steel Stack STD-MD-00040 Earthing Clips for Tanks.Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS 4. Sheet 2 STD-MD-00045 Reflux Nozzle Details. In case of conflict. Sheet 3 STD-MD-00046 Feed Nozzle Details. Sheet 1 STD-MD-00047 Feed Nozzle Details. Resolution and/or interpretation precedence shall be obtained from the COMPANY in writing before proceeding with the design/manufacture. Sheet 3 STD-MD-00049 Flash Feed Details STD-MD-00050 Liquid Drawoff and Vapor Outlet Details STD-MD-00051 Side Reboiler Draw and Return Details STD-MD-00052 Tray Support Ring Details DOCUMENT PRECEDENCE The CONTRACTOR shall notify the COMPANY of any apparent conflict between this specification. the related Data Sheets. Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 8 of 17 . Sheet 2 STD-MD-00037 Typical Vessel Ladders and Platform Details. Vessels and Supporting Structures STD-MD-00041 Warning Nameplate STD-MD-00042 Internal Pipe Support Details STD-MD-00043 Reflux Nozzle Details. Sheet 1 STD-MD-00044 Reflux Nozzle Details.0 STD-MD-00032 Vessel Tolerances STD-MD-00033 Flange Bolt Hole Orientation STD-MD-00034 Tray Support Tolerances STD-MD-00035 Tray Tolerances STD-MD-00036 Typical Vessel Ladders and Platform Details. the order of precedence shall be stated in the AGREEMENT or other PROJECT documents as applicable. 0 QUALITY ASSURANCE/QUALITY CONTROL CONTRACTOR’S proposed quality system shall fully satisfy all the elements of ISO 9001 2000 and ISO 9004 – 2000 with due regard to ISO 19011. comment and approval as required by purchase/contract documents. 10. The quality system shall provide for the planned and systematic control of all quality-related activities performed during design. Technical changes implemented prior to COMPANY approval are subject to rejection. The Criticality Rating (CR) System outlined in Project Specification DGS-MU-013 shall be used by CONTRACTOR or CONTRACTOR’S designee to develop the design checking levels and minimum requirements for shop inspection. installation or servicing (as appropriate to the given system). prior to the proposed technical changes being implemented. Concession requests require COMPANY'S review/approval. Implementation of the system shall be in accordance with the CONTRACTOR’S Quality Manual and Project Specific Quality Plan.1 DESIGN PRESSURE 10.Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS 5. 6. which shall both together with all related/referenced procedures.0 SPECIFICATION DEVIATION/CONCESSION CONTROL Any technical deviations to the this Specification and its attachments including.5 internal Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 9 of 17 .05 external/3.1.1. 7. 10. 8.0 DESIGN CRITERIA 10. testing and material certification given in Project Specification DGS-MU-014.1 All pressures shown as kg/cm2 are gauge unless specified kg/cm2 A. but not limited to.0 HANDLING Refer to DGS-MD-002. development.2 Unless otherwise specified on Project vessel Data Sheets/drawings. the internal design pressure at top tangent line shall be as follows: Maximum Operating Pressure (kg/cm2): Design Pressure (kg/cm2): Full or partial vacuum 1. the Data Sheets and Narrative Specifications shall be sought by the CONTRACTOR only through Concession Request format. be submitted to COMPANY for review.0 DOCUMENTATION Refer to DGS-MD-002.0 SUBCONTRACTORS/SUBVENDORS Refer to DGS-MD-002. 9. production. 2 The Maximum Allowable Working Temperature to be stamped on the vessel nameplate shall be equal to the maximum allowed by the design stresses without changing the flange rating.3 .2.1 For vessels operating above 0 C.3 The Minimum Design Metal Temperature of +15°C.2.00 Operating + 7.2. unless limited by the flange rating. 10.2 DESIGN TEMPERATURE 10. where applicable.5 internal 0.3 Design pressure for vessels subjected to steaming-out shall be 0. 10.1.Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS Maximum Operating Pressure (kg/cm2): Design Pressure (kg/cm2): 0 (Gauge) .4 For low temperature services.2 Operating + 1. shall be determined by using the full plate thickness as fabricated less the corrosion allowance of the weakest part of the vessel.8 3.35 0.36 .00 . 10.5 external/3. 10. 10.0.7 17. Project Specifications DGS-MD-011 and DGS-MW-001.5 The maximum allowable working pressure to be stamped on the vessel nameplate.6 Intermediate heads shall be designed based on maximum possible pressure differential under operating conditions. 4 rules apply.4 Catalyst load (including catalyst suspended liquid) or liquid static heads shall be added to the design pressure. 10. 10.1.1. Appendix No.00 140.5 kg/cm2 external at 150°C temperature.1. heads and skirts shall be as follows: Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 10 of 17 . Appendix No. 4. the design temperature shall be the operating temperature plus 10°C.17.00 – Up Operating + 5% 10.5 1.2. shall be used unless otherwise specified on Project Data Sheets/drawings or determined in Project Specification DGS-MW-001. Intermediate heads are not to be used as line of support. 10.00 Operating + 10 percent 70.81 .140.70.1.3 MINIMUM THICKNESS Minimum thickness for shells. cladding or lining thickness as specified.Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS 10.5. 10. e. For noncorrosive or very mild corrosive conditions.4.0 mm.4.4. the ASME Code Section VIII. and/or additional requirements of DGS-MW-001. c.6 mm may be specified by the "COMPANY. Carbon steel and low alloy steel pressure parts . 10.” taking into account the required lifetime of the vessel. in media such as steam. a corrosion allowance may be specified with COMPANY approval. 10.Minimum thickness shall not include the cladding. lining or cladding thickness or .3. LNG and dry natural gas service. 10.1 Carbon and low alloy steel vessels .4 CORROSION ALLOWANCE 10.3 See Specification DGS-MW-004 for vessels containing caustic.5. 10.8 mm. the procedure and requirement shall be subject to review by the CONTRACTOR/COMPANY.Minimum thickness shall be the greater of 6 mm excluding corrosion allowance. 10. 10. 10. In special cases.5. the procedure and requirement shall be approved by the CONTRACTOR/COMPANY . b. When heat treating the entire vessel in an enclosed furnace is not feasible. d. 10. amine or chlorine solutions.3 Clad vessels do not require a corrosion allowance on the carbon steel backing.5 POSTWELD HEAT TREATMENT 10.2 High alloy steel vessels . Where postweld heat treatment is required to be performed in the field.3.5.1 Postweld heat treatment shall be implemented when required by process requirements.3 For cladded or lined vessels .2 When Postweld heat treatment is required.3.3.002 x inside diameter plus 1. dry compressed air. and shall agree with ASME Section VIII. the entire vessel shall be heat treated in an enclosed furnace whenever it is feasible. Alloy Clad or Lined Vessels . Division 1. Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 11 of 17 .4 Chrome-moly material shall be postweld heat treated in all thicknesses unless otherwise specified.g. lining or weld overlay thickness. 1. No corrosion allowance is required on the gasket facing of flanges.2 Nozzles and manhole necks shall have the same corrosion allowance as specified for the shell or heads.1 Corrosion allowance shall be as specified on Project vessel Data Sheets/drawings with a minimum as follows: a. LPG.6 mm. 10. External Bolts SA-193 Gr B7 (except as noted in para. WELD OR HAMMER. Same alloy as lining for alloy clad or alloy lined vessels.1 In general. Flanges SA-105 Internal Bolts and Nuts For uncladded vessels or vessel sections: carbon steel unless otherwise noted.6 RADIOGRAPHIC WELD INSPECTION As a minimum. Tray Support Rings and Other Tray Supports welded to Vessel Carbon steel for carbon steel vessels. 10. Minimum of 10% of each process and each operator shall be taken to examine the welds. DO NOT BURN.7 MATERIALS 10. and CONTRACTOR drawings and/or Data Sheets. 10. Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Specification Initials for Piping Systems Page 12 of 17 . Same lining for alloy clad or alloy lined vessels.5) External Nuts SA-194 Gr 2H (except as noted in para.5 No welding is permitted after postweld heat treatment.7.7.General Specification DGSMD-006." 10. unless specified otherwise: Shell and Heads SA-516 Gr 55 to 65 Supports SA-285 Gr C for temperatures of 343°C or below. Add this note on vessel fabrication drawings.7. Additional radiography may be required by code or to reduce material costs. Gaskets See Technical DGS-PU-003. The vessel shall be clearly marked "POSTWELD HEAT TREATED. Trays and Tray Fasteners As specified in Vessel Trays . materials for carbon steel vessels shall be in accordance with the following ASME material specifications. Internals Same as shell and head materials.Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS 10. all vessels shall be spot examined by radiography. Same as shell over 343°C for at least 700 mm at top of skirt.5.5) Nozzle Necks SA-106 Gr B or same as shell or head. Requirements shall be shown on Project vessel Data Sheets/drawings as a minimum requirement only. Analysis and interpretation of the code shall be in accordance with Structural Engineering Criteria Specification DGS-CU-002.4 See specification DGS-MW-004 for materials requirements for all pressure containing components in wet H2S service. all pressure parts in low temperature (MDMT <15°C).25%. Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 13 of 17 .9 WIND LOAD Wind design shall be in accordance with the American Society of Civil Engineers Code.7 The VENDOR shall prove that in the as-built condition material grades actually used for the construction of low-alloy vessels comply with the requirements of the purchase order. Test pressure at the top of the vessel to be 1. Bolting materials (both external and internal) shall be specified on Project vessel Data Sheets/drawings for all other design temperature and extreme service conditions. Appendix 4. 10. 10.3 times the design pressure. as given by: CE = C + Mn 6 + Cr + Mo + V Cu + Ni + 5 15 10. amine.7.7.7. corrected for design temperature.10 HYDROSTATIC TEST 10. Hoop stress in any part of the vessel shall not exceed 90 percent of the minimum yield strength of the material multiplied by the joint efficiency. 10. except for forgings and castings. the carbon equivalents (CE) shall not exceed 0. in accordance with Project Specification DGS-MX-001.1 Field Hydrostatic Test: All vessels shall be designed for a future field hydrostatic test in the erected position and in the corroded condition as follows: a.23%. For this purpose. Structural Engineering Criteria.2 Carbon content of carbon and carbon-manganese steels shall not exceed 0. Analysis and interpretation of the Code shall be in accordance with Specification DGS-CU-002.6 Equipment bolting shall be coated.Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS 10. and toxic services shall be normalized. 10. b. 10.3 In accordance with Project Specification DGS-MW-001. caustic and criticality "CR-1" services shall be normalized. 10. All flanges in wet H2S.7.8 EARTHQUAKE LOAD Earthquake design for vessels shall be in accordance with the Uniform Building Code. liquidified gas. For pressure containing components.10. 10. as applicable. SA-193 Gr B16 and SA-194 Gr 4 shall be used. where this may be relaxed to 0.7.5 External bolting for design temperature above 450°C and up to 525°C. a nondestructive positive alloy material identification in accordance with DGS-MW-006 shall be carried out.43.7. 11 INSULATION Vessels shall be insulated in accordance with the Insulation Specification DGS-MN-001 when required by the Project vessel Data Sheets/drawings.2 The design of skirts shall be such that the temperature of any supporting concrete will not exceed 100°C. 10. Do not apply a corrosion allowance. high pressure and temperature vessels. 10.0 percent knuckle radius when the design pressure exceeds 10.13. 10. Anchor bolts shall be designed using allowable stresses in accordance with Specification DGS-CU-002. 10.14. Nonclad or lined vessels shall be tested to a calculated test pressure based on the full metal thickness (including corrosion allowance).13 SUPPORTS AND ANCHOR BOLTS 10.10.1 Two to one ratio ASME semi-ellipsoidal heads are preferred. this temperature shall be such that no condensation will occur under normal operating conditions.1 The outside diameter of vertical vessel skirts shall equal the outside diameter of the vessel shell with shell thickness up to 38 mm.e.13. large diameter.12 VESSEL FIREPROOFING Saddles supporting horizontal vessels shall not be fireproofed. i.61 kg/cm2 and/or design temperature exceeds 232°C.13. 10.15 MANWAYS AND HANDHOLES Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 14 of 17 .3 Anchor bolts shall be 19 mm diameter minimum size. Allowable stresses shall be based on new and cold condition. the skirts of vertical vessels shall be fireproofed as follows: Vessel Diameter Internal Protection External Protection 1220 mm and less None 50 mm concrete Over 1220 mm and larger 50 mm concrete 50 mm concrete 10.14. Hemispherical heads are acceptable under certain conditions.2 Conical heads or transitions shall have a 9. 10. For vessels with operating temperatures below ambient. When specified on the vessel drawing or data sheet.14 HEADS 10.. 10. The mean diameters of the skirt and shell shall align for shell thickness over 38 mm.2 Shop Hydrostatic Test: Integrally clad vessels shall be tested to a calculated test pressure based on the full metal thickness (base metal plus cladding).Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS 10. Additional manways shall be provided between trays. For spiral wound and flexible graphite based gaskets. PLATFORMS AND DAVITS Ladders.15. socket welded.5 Flange Face Finish a. Additional manways shall be provided as required for service conditions and maintenance. Slip-on and lap joint flanges are not permitted unless otherwise approved by COMPANY.Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS 10. one above the tray section and one below the tray section.3 Top and side entry manways shall be provided with a davit.15. platforms and column davits shall be provided in accordance with Specification DGS-MD-008. 10.1. 10.2-6. 10. the recommended number of trays between manways will be 10.17.15.16 LADDERS. 10.5 The minimum diameter for inspection openings (handholes) is 150 mm nominal.17 NOZZLES 10. shall be provided on columns with trays. 10. Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 15 of 17 . pad type or built-up type and screwed connections are not permitted.17. 10. Manway size for small diameter vessels shall be analyzed on a case by case basis. The minimum nozzle size shall be 2 inches.5 and to the applicable Piping Specification.2 Stubbed.17.6 Manway and handhole covers shall be flat type of rolled or forged plate.4 Bottom entry manways shall be provided with hinges.2 A minimum of one 610 mm (24") nominal manway shall be provided for other vessels. 10.3 All 2 inch connections shall be a minimum of Class 300 and shall be braced with two gusset plates at 90° orientation apart. Rating and facing of flanged nozzles shall conform to ASME B16. Flanged connections inside skirts of vertical vessels are not permitted unless otherwise approved by CONTRACTOR/COMPANY.4 All connections on which relief valves are mounted shall be Class 300 minimum. Welding neck type flanges with raisedface shall be used. 10.15.3 µm Ra (smooth finish) in accordance with ASME B46.15. 10.17.1 All nozzles on pressure vessels shall be flanged. Handhole covers shall be provided with hand grips. 10.15. resulting in a roughness height within the range of 3. 10.1 A minimum of two 610 mm (24") nominal manways.17. the gasket contact surfaces shall have concentric or spiral grooves. the gasket contact surfaces shall be 0. the gasket contact surfaces shall be 0.17. When Minimum Design Metal Temperature (MDMT) is equal to or lower than -29°C. c. They shall also be required on refractory lined vessels operating over 399 C. 10. Shell and head mounted nozzles and manways with integral reinforcement shall be used when the design temperature of the vessel shell/head or nozzle wall is above 399 C. For jacketed type gaskets. Reinforcing pads shall not be used in hydrogen service above 230°C.8 .6 µm Ra.6 µm Ra. c.8-1.1.Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS b. 10. Larger nozzles shall be a minimum of 12 mm wall.7 Nozzle Reinforcement 10. b. PAINTING All designated vessel surfaces shall be prepared and painted in accordance with Painting Specification DGS-MX-001.17. Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Initials Page 16 of 17 . For solid metallic type gaskets.6 8" and smaller pipe size nozzle necks shall be a minimum of schedule 80 seamless pipe.18 a. integrally reinforcing forged neck shall be used. Date Proposed Revision Takreer DGS-MD-001-Rev-1 April-2009 Printed 16-Apr-09 13:58:29 Remarks Initials Page 17 of 17 .Abu Dhabi Oil Refining Company DGS-MD-001 Rev-1 April 2009 VESSEL DESIGN BASIS ADDENDUM SHEET All revisions to this DGS subsequent to the issue of Rev Zero shall be recorded in this addendum sheet and shall be incorporated into the DGS in the next revision.