PIP VECV1001 Design Criteria and Purchasing Requirements for Vessels ASME Code Section VIII, Divisions 1 and 2

Transcription

1 September 2017 Vessel PIP VECV1001 Design Criteria and Purchasing Requirements for Vessels

2 PURPOSE AND USE OF PROCESS INDUSTRY PRACTICES In an effort to minimize the cost of process industry facilities, this Practice has been prepared from the technical requirements in the existing standards of major industrial users, contractors, or standards organizations. By harmonizing these technical requirements into a single set of Practices, administrative, application, and engineering costs to both the purchaser and the manufacturer should be reduced. While this Practice is expected to incorporate the majority of requirements of most users, individual applications may involve requirements that will be appended to and take precedence over this Practice. Determinations concerning fitness for purpose and particular matters or application of the Practice to particular project or engineering situations should not be made solely on information contained in these materials. The use of trade names from time to time should not be viewed as an expression of preference but rather recognized as normal usage in the trade. Other brands having the same specifications are equally correct and may be substituted for those named. All Practices or guidelines are intended to be consistent with applicable laws and regulations including OSHA requirements. To the extent these Practices or guidelines should conflict with OSHA or other applicable laws or regulations, such laws or regulations must be followed. Consult an appropriate professional before applying or acting on any material contained in or suggested by the Practice. This Practice is subject to revision at any time. Process Industry Practices (PIP), Construction Industry Institute, The University of Texas at Austin, 3925 West Braker Lane (R4500), Austin, Texas PIP Member Companies and Subscribers may copy this Practice for their internal use. Changes or modifications of any kind are not permitted within any PIP Practice without the express written authorization of PIP. Authorized Users may attach addenda or overlays to clearly indicate modifications or exceptions to specific sections of PIP Practices. Authorized Users may provide their clients, suppliers and contractors with copies of the Practice solely for Authorized Users purposes. These purposes include but are not limited to the procurement process (e.g., as attachments to requests for quotation/ purchase orders or requests for proposals/contracts) and preparation and issue of design engineering deliverables for use on a specific project by Authorized User s client. PIP s copyright notices must be clearly indicated and unequivocally incorporated in documents where an Authorized User desires to provide any third party with copies of the Practice. PUBLISHING HISTORY September 1997 Issued February 2007 Complete Revision September 2017 Complete Revision February 1999 Complete Revision May 2009 Editorial Revision August 2000 Complete Revision March 2012 Complete Revision Not printed with State funds

3 September 2017 Vessel Table of Contents PIP VECV1001 Design Criteria and Purchasing Requirements for Vessels 1. Scope References Process Industry Practices Industry Codes and Standards Government Regulations Other References Definitions Requirements Overall Responsibilities Design Materials Examination, Inspection and Pressure Testing Process Industry Practices Page 1 of 24

4 1. Scope This Practice provides requirements for use by a Purchaser for determining the design criteria for pressure vessels constructed in accordance with ASME Boiler and Pressure Vessel Code, Section VIII, Division 1 or Division 2, henceforth referred to as the Code. Requirements that are specific to Code, Section VIII, Division 2 are shown in braces { }. This Practice describes the requirements for the design, materials of construction, inspection and testing of pressure vessels constructed in accordance with Code, Section VIII, Division 1 {or 2}. Guidance is also provided for the development of purchase specifications for the construction of new pressure vessels which meet the philosophy and requirements of Code, Section VIII, Division 1 {or 2}. This Practice also applies to shell-and-tube exchangers. See PIP VECST001 and PIP VESST002 for the additional requirements specific to exchangers only. This Practice is intended to be used for the purchase of vessels where the Manufacturer is also responsible for performing detailed design for the vessels in accordance with the Code. If Purchaser also performs a detailed design, the design shall also be in accordance with PIP VESV1002. The following are not covered by this Practice: a. Standardized pre-designed (i.e., off-the-shelf) vessels (see PIP VESSM001) b. Vessels with layered construction c. Small vessels and low-pressure vessels (see PIP VESSM001 and PIP VESLP001) d. Process design of trays and other removable internals 2. References Applicable parts of the following Practices, industry codes and standards, government regulations, and references shall be considered an integral part of this Practice. The edition in effect on the date of contract award shall be used, except as otherwise noted. Short titles are used herein where appropriate. 2.1 Process Industry Practices (PIP) PIP VEDV Documentation Requirements for Vessels, ASME Code Section VIII, Divisions 1 and 2 PIP VEFV Vessel/Heat Exchanger Standard Details PIP VEFV Vessel Manway Hinges PIP VEFV Vessel Vertical Manway Davits PIP VEFV Vessel Horizontal Manway Davits PIP VEFV Vessel Vortex Breakers PIP VEFV Vessel Internal Ladders PIP VEFV Skirt Attachments Process Industry Practices Page 2 of 24

5 PIP VESSM001 - Specification for Small Pressure Vessels and Heat Exchangers with Limited Design Conditions PIP VESLP001 - Low Pressure, Welded Vessel Specification PIP VECST001 - Supplemental Design Criteria and Purchasing Requirements for Shell and Tube Heat Exchangers, PIP VESST002 - Supplemental Design and Fabrication Specification for Shell and Tube Heat Exchangers, PIP VESV Design and Fabrication Specification for Vessels, ASME Code Section VIII, Divisions 1 and Industry Codes and Standards For each of the following reference documents, if Code, Table U-3 {1.1} lists an edition or addenda different than the edition listed in the reference, the edition listed in Code, Table U-3 {1.1} shall be used. American Petroleum Institute (API) API Welded Steel Tanks for Oil Storage API RP Damage Mechanisms Affecting Fixed Equipment in the Refining Industry American Society of Civil Engineers (ASCE) ASCE 7 - Minimum Design Loads for Buildings and Other Structures American Society of Mechanical Engineers (ASME) ASME Boiler and Pressure Vessel Code Section I - Power Boilers Section II - Materials, Parts A, B, C, D Section VIII - Pressure Vessels, Divisions 1 and 2 Section IX - Welding and Brazing Qualifications Code Case Pneumatic Testing of Pressure Vessels, UG-20, Section VIII, Division 1 Code Case Omission of Lifting Device Requirements for Pressure Relief Valves on Air, Water over 140 F (60 C), or Steam Service, Section VIII, Divisions 1 and 2 ASME B1.1 - Unified Inch Screw Threads (UN and UNR Thread Form) ASME B Pipe Flanges and Flanged Fittings, NPS 1/2 through NPS 24 ASME B Factory-Made Wrought Buttwelding Fittings ASME B Forged Fittings, Socket-Welding and Threaded ASME B Large Diameter Steel Flanges, NPS 26 through NPS 60 ASME PCC-1 - Guidelines for Pressure Boundary Bolted Flange Joint Assembly ASME PCC-2 - Repair of Pressure Equipment and Piping Process Industry Practices Page 3 of 24

6 Welding Research Council (WRC) WRC Bulletin Damage Mechanisms Affecting Fixed Equipment in the Pulp and Paper Industry WRC Bulletin Damage Mechanisms Affecting Fixed Equipment in the Refining Industry WRC Bulletin Damage Mechanisms Affecting Fixed Equipment in the Fossil Electric Power Industry 2.3 Government Regulations U. S. Department of Labor, Occupational Safety and Health Administration (OSHA) OSHA 29 CFR (k)(3)(ii) - Permit-Required Confined Spaces for General Industry 2.4 Other References Dynamic Response of Tall Flexible Structures to Wind Loading. Joseph Vellozzi, Ph.D., P.E. U.S. Department of Commerce, National Bureau of Standards, Building Science Series Number 32, Process Equipment Design. Brownell and Young. Wiley & Sons Publishers, Stresses in Large Cylindrical Pressure Vessels on Two Saddle Supports, L.P. Zick, Pressure Vessels and Piping: Design and Analysis, A Decade of Progress. Vol. 2, Wind Loads on Petrochemical Facilities, ASCE Task Committee on Wind- Induced Forces, Wind Loads and Anchor Bolt Design for Petrochemical Facilities. (ISBN ) 3. Definitions Code: The ASME Boiler and Pressure Vessel Code, Section VIII, Division 1{or 2} and reference sections (e.g., Section II and Section IX) and any Code Cases permitted by the User. References to Division 2 are identified in braces { }. construction: An all-inclusive term comprising materials, design, fabrication, examination, inspection, testing, certification (i.e., Code stamp and Manufacturer s Data Report), {Manufacturer s Design Report}, and pressure relief. cyclic service: A services that requires fatigue analysis in accordance with Code, Section VIII, Division 2, Section This applies to Division 1 and Division 2 vessels. Manufacturer: The party who designs and constructs the vessels. In accordance with the Code definition, the Manufacturer is the party that possesses a valid Certificate of Authorization to manufacture pressure vessels with the ASME Mark. National Board: The National Board of Boiler and Pressure Vessel Inspectors, an organization comprised of chief inspectors of various governmental jurisdictions in the United States and Canada. Process Industry Practices Page 4 of 24

7 Owner: The party who owns the facility wherein the vessel will be used. The owner is typically also the User. Purchaser: The party who selects and specifies the mechanical design requirements (e.g., Vessel Drawing/Data Sheet {User s Design Specification}), consistent with User criteria, for use by the Manufacturer. The Purchaser is also responsible for placing the purchase order for the vessel or vessel components. The Purchaser may also be the Owner, User, or the Owner s or User s Designated Agent (e.g., engineering contractor). Retrieval system: As defined by OSHA 29 CFR means the equipment (including a retrieval line, chest or full-body harness, wristlets, if appropriate, and a lifting device or anchor) used for non-entry rescue of persons from permit spaces. User: The party who establishes construction criteria in accordance with the Code philosophy and service hazards. The User is the operator of the facility wherein the vessel will be installed. Purchaser s Inspector: The person or company authorized by the Purchaser, Owner and/or User to inspect pressure vessels to the requirements of this Practice and the Purchaser s requirements. 4. Requirements 4.1 Overall Responsibilities Vessels shall be configured and specified in accordance with the requirements of this Practice, the Code, other standards as referenced in this Practice, local requirements, and the other contract documents furnished by the Owner This Practice shall be used in conjuction with PIP VESV1002, the data forms included in PIP VEDV1003, and applicable details included in PIP VEFV1100 to prepare a complete vessel purchase specification All aspects of the work shall be performed in accordance with applicable local, county, state, and federal rules and regulations. These include, but are not limited to, the rules and standards established by EPA and OSHA, or applicable national standards at the installation site. All applicable jurisdictional requirements, including those that are site-specific, shall be identified and specified on the PIP VEDV1003-D Data Sheet Exceptions to the Code requirements shall not be permitted Applicable Code Scope Exemptions The Code scope exemptions that represent across-the-board acceptance are those covered under Code Paragraphs U-1(c)(2)(h) { h} and U-1(c)(2)(i) { i)} Section is not intended to prohibit the use of other scope exemptions in Code Paragraph U-1(c)(2) { }; however, such use shall be by agreement with the User All design loads and load combinations shall be determined and specified on the PIP VEDV1003-D Data Sheet to provide a basis for design and fabrication. Process Industry Practices Page 5 of 24

8 4.1.7 The external environment (e.g., wind, seismic, etc.) to which the vessels are exposed and the intended function of the vessels shall be determined to provide a basis for design The mechanical loads imposed on the vessels, vessel geometry, specific support requirements, and specific codes and laws applicable where the vessel is to be installed shall be determined to provide a basis for design and fabrication The documentation described in PIP VEDV1003 shall be prepared for submittal to the Manufacturer with the purchasing inquiry The PIP VEDV1003-D Data Sheet specifies that National Board registration of vessels stamped with the Code U { U2 } symbol is required, as the default requirement. However, this may be over-ridden by the Purchaser if required Waste Heat Recovery Vessels Steam generating vessels associated with waste heat recovery operations shall be constructed and stamped with the Code U symbol in accordance with Code, Section VIII, Division Dual Code symbol stamping of steam generating vessels associated with waste heat recovery operations (both Section I S symbol and Section VIII, Division 1 U symbol) shall not be permitted The system of measurement units (See Code Paragraph U-4 {1.4}, whether U.S. customary units or metric units, to be used in all documentation including drawings and calculations shall be shown on the PIP VEDV1003-D Data Sheet. 4.2 Design Design Pressure and Temperature The design pressure and coincident maximum metal temperature shall be determined by the Purchaser considering all operating phases and associated loadings (e.g., liquid head and other sources of pressure variation, such as resulting from flow) that the vessel can experience during the specified vessel life, such as the following: a. Initial startup b. Normal operations c. Temporary operations d. Emergency shutdown e. Emergency operations f. Normal shutdown g. Startup following a turnaround or an emergency shutdown h. Cleaning, steam out, and decontamination i. Upset conditions j. Safety and health, e.g. environmental restraints on relief venting k. Lift conditions Process Industry Practices Page 6 of 24

9 The margin above the maximum anticipated operating pressure selected to establish the design pressure and coincident maximum metal temperature shall be considered for each vessel component as a function of the overall objective with respect to pressure relief, coupled with the uncertainties in determining what actual pressures can be developed Overpressure protection by system design in accordance with UG-140 {9.7} may be used in lieu of and shall be carried out by the Purchaser and be so indicated in the purchase order documents to the Manufacturer If approved by the authority having legal jurisdiction over the installation of pressure vessels (if applicable), the advantages of using the provisions of Code Case 2203 shall be considered For common components of multi-chamber or compartmented vessels, the most severe combinations of pressure, temperature, and other loadings which can occur during operation (see list in Section ) and test conditions shall be determined and specified. Simultaneous loading of internal pressure in adjacent compartments shall not be considered as a means to reduce the design loadings Minimum Design Metal Temperature (MDMT) and Coincident Pressure The MDMT and coincident pressure to be marked on the Code nameplate shall be determined considering the operating phases such as those listed in Section and in accordance with Code, Paragraph UG-20(b) { e)} If atmospheric temperatures govern the metal temperatures during startup or normal operations, the lowest 1-day mean atmospheric temperature at the installation site shall be considered. If applicable, API 650, Figure 4-2 may be used to establish the lowest 1-day mean temperatures When determining the design loads, the mean metal temperature during shop and future field pressure testing shall be considered External Pressure Design In a manner similar to that described in Section , the external design pressure and coincident temperature shall be established by determining requirements for external pressure based on the expected operation of the vessel and adding a suitable operating margin Non-jacketed vessels subjected to operating pressure less than atmospheric or subjected to steam-out conditions shall have full vacuum as a design condition. Consideration shall be given to external pressures caused by sudden cooldown of gases or vapors in the vessel or by the sudden emptying of the vessel contents Loads and Load Combinations Design Loads Design loads are defined in PIP VESV1002. The magnitudes of these loads shall be specified on the PIP VEDV1003-D Data Sheet or sufficient Process Industry Practices Page 7 of 24

10 data shall be provided in the purchase order documents such that the loads can be determined by the Manufacturer Load Conditions 1. Default load conditions are specified in PIP VESV1002. Any additional load conditions shall be specified on the PIP VEDV1003-D Data Sheet. 2. Site erection details for the vessel shall be provided and identified on the PIP VEDV1003-D Data Sheet. The details shall include the means to erect, specify whether internals, insulation, and other attachments are installed, specify the allowable wind speed, and identify the party responsible for the lift Wind Load Unless local codes or regulations require compliance with other rules for wind load design, wind loads shall be in accordance with ASCE The wind design parameters shall be determined and specified on the PIP VEDV1003-D Data Sheet If the Manufacturer s design proposal requires the installation of spoilers for wind-induced vibration, an evaluation shall be performed regarding which type of spoilers (i.e., helical or short vertical) shall be used. See Dynamic Response of Tall Flexible Structures to Wind Loading by Vellozzi Seismic Loads Unless local codes or regulations require compliance with other rules for seismic design, seismic loads shall be in accordance with ASCE The seismic parameters shall be determined and specified on the PIP VEDV1003-D Data Sheet Cyclic Service General 1. The possibility of cyclic service in the life of the vessel shall be considered. 2. Cyclic and dynamic reactions from any mechanical or thermal loading source shall be considered in design in accordance with Code, Paragraph UG-22(e) { }. For example, batch operation vessels and vessels having agitators frequently fall into this category. 3. If a fatigue analysis by the Manufacturer is required, it shall be specified on the PIP VEDV1003-D Data Sheet Number of Cycles {See 5.5.2} Code vessels shall be considered to be in cyclic service if the sum of the number of cycles in the following three is greater than 1000 cycles in the expected design life of the vessel: Process Industry Practices Page 8 of 24

11 a. The expected number of full range (design) pressure cycles, including startups and shutdowns b. The expected number of operating pressure cycles in which the range of pressure variation is greater than 20% of the design pressure c. The expected number of thermal cycles in which the metal temperature differential between any two adjacent points is greater than 50ºF (28ºC). {For a definition of adjacent points, see Step 4.} Fatigue Loading Data The applicable fatigue loading data shall be determined and specified on the PIP VEDV1003-D Data Sheet Formed Heads The required head geometry shall be specified on the PIP VEDV1003-D Data Sheet Nozzles Vessels shall be specified with sufficient connections to permit purging, pump-out, venting, decontamination, pressure relieving, and draining Vortex breakers shall be specified on pump suction nozzles. (See PIP VEFV1124.) For vessels supported by a skirt, the flange of any nozzle in the bottom head shall be located outside the skirt Nozzles (including attached piping) within or passing through vessel support skirts shall be specified with the following: a. Adequate support for the operating conditions and for protection during shipping and handling b. Adequate clearance for differential thermal expansion between the skirt and nozzle in both the vertical and horizontal directions For establishing nozzle and manway projections, clearance shall be specified for removing flange stud bolts from between the flange and vessel and for accessing flange stud nuts Clearance for flange studs and nuts shall be considered if nozzles penetrate insulation or platforms Minimum projection from the outside of the vessel wall to the nozzle face shall be as follows: a. 8 inches (200 mm) for nozzles less than or equal to NPS 8 (DN 200) b. 10 inches (250 mm) for nozzles greater than NPS 8 (DN 200) The dimension from the face of the nozzle to the vessel centerline or reference line shall be rounded up to the next larger 12.7 mm (1/2-inch) increment Nozzle data, as described above, shall be specified on the PIP VEDV1003-D Data Sheet. Nozzle projections, elevations, and orientations shall be shown on a sketch or drawing. Process Industry Practices Page 9 of 24

12 Manways The location, quantity, and size of manways and internal ladder rungs shall be specified to ensure that all interior areas are accessible as required Minimum requirements for manway and inspection openings shall be in accordance with Code Paragraph UG-46 {4.5.16} Service conditions, size, and configuration of the vessel may justify manways other than (or in addition to) those mandated by the Code. Manways shall be specified for the following: 1. Vessels with mixers/agitators shall be specified with at least one manway that does not require removal of the mixer/agitator. 2. Towers with feed and distribution trays shall have manways as follows: a. Manways shall be spaced as follows: (1) Short towers (less than 60 trays) - Manways spaced 20 trays apart (2) Medium towers ( trays) - Manways spaced 30 trays apart (3) Tall towers (greater than 120 trays) - Manways spaced 40 trays apart b. A manway shall also be located about 1 m (3 ft) above the bottom head seam, and another manway shall be located at the top of the tower, 450 mm (18 inches) above the top tray. 3. Packed towers shall have manways at all locations where there is feed distribution or redistribution of liquid Vessels having inside diameters 1 m (3 feet) or less and subject to internal corrosion, erosion, or mechanical abrasion shall be specified with inspection openings in accordance with Code Paragraph UG-46 {4.5.16} Vessels having inside diameters greater than 1 m (3 feet) and subject to internal corrosion, erosion, or mechanical abrasion shall be specified with one or more flanged and blinded manways Unless otherwise approved by Owner, manways less than NPS 24 (DN 600) are not permitted Manways greater than NPS 24 (DN 600) shall be specified to satisfy additional requirements (e.g., installation of internals/catalyst, packing, maintenance requirements, long projection due to thick insulation, etc.) Manways shall be usable from scaffolding, platform, or grade To provide utility for entry and exit, vessel geometry, and location of access platforms shall be considered when locating manways. Process Industry Practices Page 10 of 24

13 Internal ladders or grab rungs shall be considered at manway locations for entry and exit. See PIP VEFV1125. For corrosive or erosive services, internal ladders are not permitted Safe access and egress through manways shall be considered, including the need for retrieval systems at manways for personnel rescue in accordance with OSHA 29 CFR , or equivalent national standard. Permanent attachments, if any, shall be specified. User shall be consulted regarding proposed designs of retrieval systems Manways shall be specified with either a davit or a hinge in accordance with the following requirements to facilitate handling of the blind flange: a. Manways oriented with the nozzle neck axis in a horizontal plane shall be specified with a hinge in accordance with PIP VEFV1116 or a davit in accordance with PIP VEFV1117. b. If lap joint flanges are used, the davit-socket bracket shall be attached to the nozzle neck. c. Manways on the top of vessels oriented with a vertical nozzle neck axis shall be provided with a davit in accordance with PIP VEFV Consideration may be given for use of suitable process connections as manways and handholes. Both size and location of connections should be considered Flanges The facings, bolt circle, number of bolts, and size of bolts of vessel nozzles shall match the mating piping flanges Weld neck flanges shall be specified except as permitted elsewhere in this Practice Flanges for all flanged vessel nozzles equal to or smaller than NPS 24 (DN 600) shall be in accordance with ASME B Body flanges equal to or smaller than NPS 24 (DN 600) may be either in accordance with ASME B16.5 or custom-designed in accordance with the Code For nozzles and body flanges larger than NPS 24 (DN 600), flanges shall be specified in accordance with one of the following types: a. ASME B16.47, Series A (NPS 26 through NPS 60) b. ASME B16.47, Series B (NPS 26 through NPS 60) c. Custom-Designed Flanges Custom-designed flanges shall be required if any of the following apply. Appropriate design data from the following list shall be shown on the PIP VEDV1003-D Data Sheet or on a flange drawing. Process Industry Practices Page 11 of 24

14 (1) Materials of construction covered in ASME B16.5 or ASME B16.47 are not appropriate for the service conditions. (2) For NPS 26 through NPS 60, the preferred flange style is other than the welding neck type (e.g., lap joint, slip-on) covered in ASME B (3) Design conditions for the intended service application exceed the pressure-temperature ratings of ASME B16.5 or ASME B16.47 flanges. (4) Service requirements result in significant mechanical loadings other than pressure. (5) If increased rigidity is required. See Code paragraph 2-14 {Table } for Rigidity Index requirements. d. Custom-Designed Lap Joint Flanges See PIP VESV1002 Section for additional requirements specific to custom designed lap joint flanges. e. Flange Bolt Tension Indicators Lap Joint Flanges For flanged joints with 2-inch (50 mm) diameter and greater bolting, to provide high bolt-load control accuracy during initial assembly and during operation at temperature, specific provisions for load indicator rods shall be developed and specified on PIP VEDV1003-D Data Sheet, Part D, line 23. Unless otherwise approved by Owner, lap joint flanges are not permitted. Where lap joint flanges are permitted they shall comply with the following: 1. Unless a higher temperature is justified by a complete stress analysis and approved by User, carbon or low-alloy steel flanges attached to solid high-alloy necks limited to design temperatures not greater than 450ºF (230 C) 2. MDMT not colder than -29 C (-20ºF) for carbon and low-alloy steels 3. Vessel not for lethal service (Code requirement) 4. Vessel or nozzle neither subject to cyclic pressure or temperature service nor subjected to cyclic loadings from associated equipment 5. For sizes of NPS 24 (DN-600) and smaller the flanges shall comply with ASME B16.5 lapped flanges. 6. For sizes larger than NPS 24 (DN 600) lap joint flanges shall comply with the following: a. The flange shall have the same dimensions as B16.47 Series A or B. Process Industry Practices Page 12 of 24

15 b. The strength of lap joint flanges shall be justified by Code calculations Slip-on Flanges Slip-on flanges shall be permitted for only the following conditions: a. ASME B16.5 standard forged flanges for design pressures and coincident temperatures not greater than the pressure-temperature ratings for Class 150 flanges in accordance with ASME B16.5, except that the maximum design temperature shall not be greater than 230 C (450 F) b. Custom-designed flanges in accordance with Code Figure 2-4(8), (8a), (9), (9a), (10), or (10a){Figure (a) or (b)} for design temperatures not greater than 345ºC (650ºF); and for flange thickness not greater than 75 mm (3 inches) c. Corrosion allowance not greater than 1.5 mm (1/16 inch) d. Unless a higher temperature is justified by a complete stress analysis and approved by User, carbon or low-alloy steel flanges attached to solid high-alloy necks limited to design temperatures not greater than 230 C (450ºF) e. MDMT not colder than -29 C (-20ºF) for carbon and low-alloy steels f. Vessel not for lethal service (Code requirement) g. Vessel or nozzle neither subject to cyclic pressure or temperature service nor subjected to cyclic loadings from associated equipment h. Vessel not in hot hydrogen service Threaded flanges and socket weld flanges are not permitted. See Section Piping Connections 1. Except as specified in Section , piping connections to vessels shall be either flanged or butt-welded. 2. The minimum size flanged or butt-welded connection shall be NPS 1-1/2 (DN 40). 3. Threaded connections may be considered for vents, drains, or instrument connections. 4. If threaded connections are used, the following shall apply: a. Minimum connection size shall be NPS 3/4 (DN 20) Schedule 160 or 6000# coupling. (See ASME B16.11.) b. Maximum connection size shall be NPS 1-1/2 (DN 40). 5. Connection sizes (of any type) NPS 1-1/4, 2-1/2, 3-1/2, 5, and 22 (DN 32, 65, 90, 125, and 550) shall not be permitted For quick-opening closures, the swing bolt material shall be specified on the PIP VEDV1003-D Data Sheet. Process Industry Practices Page 13 of 24

16 Flanged joints for stainless steel and nonferrous alloy connections may be of the lap-joint type with carbon or low-alloy steel flanges if both of the following apply: a. Nominal diameter of the vessel connection is not greater than NPS 24 (DN 600). b. Maximum temperature stamped on the Code nameplate is not greater than 150 C (300 F) For flanged joints with dissimilar metals, the following apply: a. Austenitic stainless steel or nonferrous alloy flanges may be bolted to carbon steel flanges if the differential diametrical expansion cannot cause diametrical interference of recessed (e.g., tongue and groove) joints and cannot be greater than 0.8 mm (1/32 inch). b. Bolting joining a carbon steel flange to a stainless steel or nonferrous alloy flange shall be of low-alloy steel Requirements for studded connections and indicator-type studs shall be specified on the PIP VEDV1003-D Data Sheet Vessel Supports The minimum design metal temperature for the vessel support assembly shall not be warmer than the lowest 1-day mean atmospheric temperature at the installation site. (See Section ) Vertical Vessels 1. Skirts or lugs shall be used to support towers or large vertical vessels and are preferred for vessels having top-entering agitators. 2. Leg supports shall be limited to spherical and cylindrical vessels that are in accordance with the following: a. Operating temperature not warmer than 230 C (450 F) b. Service noncyclic and nonpulsating c. Vessel h/d ratio not greater than 5, where height (h) is the distance from base of support to the top tangent line of the vessel. 3. The following information shall be specified: a. Type of skirt or leg attachment detail in accordance with PIP VEFV1128. The required attachment detail shall be specified on the PIP VEDV1003-D Data Sheet, Part C. b. For skirt supports, the type of anchor ring assembly (e.g., single ring with gussets, single ring with chairs, double ring with gussets, etc.) c. Type/degree of nondestructive examination of the skirt assembly welds Process Industry Practices Page 14 of 24

17 Horizontal Vessels 1. Horizontal vessels shall be designed with two saddle supports. The saddle locations shall be specified on the PIP VEDV1003-D Data Sheet. 2. One of the two saddles shall be fixed and have holes sized for the anchor bolts. The other saddle shall be the sliding type with slotted holes to permit expansion of the vessel. 3. Saddle supports shall be located a maximum distance of R o/2 from the head tangent lines, where R o is the shell outside radius. 4. Unless temporary members are attached at each support to provide necessary extension until the vessel is placed in permanent position, the bottoms of the saddle supports shall extend 1 inch (25 mm) minimum below nozzles or other projecting vessel components. 5. Wear plates, if required under the vessel, shall be specified on the PIP VEDV1003-D Data Sheet. 6. If saddles are used with weigh cells or slide plates, the associated data required for the vessel design shall be provided on the PIP VEDV1003-D Data Sheet or a separate document Anchor Bolts Anchor bolting shall be designed by the Manufacturer but furnished and installed by the Purchaser Materials for anchor bolts shall be by the Purchaser. The material selected should be from one of the following types: 1. Carbon steel: A-36, A-307 Grade B, or F-1554 Gr Low-alloy steel: A-193 B7 3. For corrosive conditions, stainless steel or other high alloy materials Anchor bolt material, corrosion allowance, shape, and any coating shall be specified on the PIP VEDV1003-D Data Sheet to enable associated vessel design by the Manufacturer Design concrete bearing stress may be increased above the default value specified in PIP VESV1002 Section if consistent with the ultimate strength of the concrete and other provisions of state-ofthe-art concrete foundation design Unless the bolts are stainless steel, anchor bolts embedded in concrete foundations shall be zinc-coated (i.e., hot dip galvanized or mechanically zinc-coated) so that the addition of a corrosion allowance is not required If J-bolts are used, the bolts shall be fully stress relieved at 595 C (1100 F) for one hour per inch of diameter before hot dip galvanized coating. Threaded J-bolts in the bent area shall not be permitted. Process Industry Practices Page 15 of 24

18 Internals The location of all vessel internals, including grab rungs if required, shall be shown on the PIP VEDV1003-D Data Sheet sketch Removable internals shall be sized to pass through designated vessel openings Vessel internals (e.g., distributors, dip tubes, baffles, and thermowells) shall not be located near manways in a manner that interferes with personnel access or rescue Consideration shall be given to the area directly below manways and to head knockers above manways. If required, grab rungs shall be specified. 4.3 Materials General Vessel materials shall be compatible with Code temperature limitations. See applicable General Notes to the allowable stress tables in Code Section II, Part D, Notes in ASME B16.5 Table 2, etc When selecting the materials of construction and the associated MDMT to be stamped on the vessel, the cost of heating the test fluid for shop or future field hydrostatic tests shall be considered. The temperature of the pressure-resisting components shall be MDMT plus at least 30 F (17 C) during the tests Dual (Multiple) Marked Materials For dual-marked materials and standard pressure parts that are in accordance with Code requirements (e.g., flanges and pipe fittings in accordance with Code paragraph UG-44 { }), parts of the vessel, if any, to be constructed with dual marked materials shall be specified on the PIP VEDV1003-D Data Sheet Corrosion and Erosion Allowance General 1. When selecting the materials of construction, all damage mechanisms associated with the service fluid at design conditions shall be considered. Guidance regarding metallurgical phenomena is provided in, API RP 571, Section II, Part D, Appendix A, and WRC Bulletins 488, 489 and Corrosion and erosion allowances shall be based on process conditions and shall be determined from past experience in similar operating environments. If past experience is not available, such as with a new process, Purchaser s material engineer shall examine the process and determine the expected corrosion rate. 3. Corrosion and erosion allowances shall be compatible with design life requirements. The vessel design life shall be determined with the concurrence of the User. Process Industry Practices Page 16 of 24

19 4. Corrosion and erosion allowances shall be combined and specified on the PIP VEDV1003-D Data Sheet Corrosion Loss 1. Corrosion loss shall be addressed by adding metal thickness to compensate for anticipated loss due to metal reacting with the environments to which it is subjected including cleaning operations, shutdowns, etc. 2. The corrosion allowance to be applied to the vessel internal surface, to nozzles, and to each wetted surface of internal parts shall be specified on the PIP VEDV1003-D Data Sheet. 3. If required, a corrosion allowance for external corrosion shall be specified Erosion Loss 1. Erosion loss shall be compensated by adding metal thickness in specific locations where metal loss is expected because of process stream flow that is of high velocity or abrasive. 2. Erosion loss typically occurs within a definable area, and compensation may be provided using the following methods as appropriate: a. Weld overlay of the area with the intent that the overlay is sacrificial b. Addition of a welded wear plate with the intent that the plate is sacrificial. For hydrogen service, this method should be used with caution. c. Internal refractory linings d. Increase of inlet nozzle size Stress Corrosion Cracking Protection Insulated austenitic stainless steel equipment that is susceptible to atmospheric chloride stress corrosion cracking shall be protected by a suitable external protective coating and the use of low-chloride insulation The required coating or insulation protection shall be specified on the PIP VEDV1003-D Data Sheet Support Materials The materials and thicknesses selected for supports shall be suitable for the maximum and minimum design metal temperatures and the imposed loadings If the maximum temperature stamped on the Code nameplate is warmer than 230 C (450 F), the skirt for stainless steel or other high-alloy steel vessels shall be as follows: a. The portion of the skirt attached to the vessel shall be constructed from a material with essentially the same coefficient of expansion as the head to which it is attached. Process Industry Practices Page 17 of 24

20 b. The length of the high-alloy steel portion of the skirt that is attached to the vessel shall be 2 ( Rt ), but not less than 300 mm (12 in), where R is the mean skirt radius and t is skirt thickness. c. The lower portion of the skirt that is not attached to the vessel may be constructed of carbon or low-alloy steel If the maximum temperature stamped on the Code nameplate is between -20 F ( 29 C) and 450 F (230 C), the entire vessel skirt may be constructed from carbon or low-alloy steel If the vessel design temperature is colder than -29 C (-20 F), the following shall apply for the types of support systems cited: a. The portion of a skirt attached to a vessel shall be constructed from the same material as the head, and shall be a minimum length of 2 ( Rt ), but not less than 300 mm (12 inches). b. The material for the top 12 inches of leg supports attached to a vessel shall be compatible with the vessel design temperature. c. Lug supports and saddles shall be rated for the minimum design vessel temperature The required materials, dimensions, and corrosion allowance, if any, for the vessel supports shall be specified on the PIP VEDV1003-D Data Sheet External Attachments As a minimum, external attachments shall be of the same type material (i.e., Code P-number) as the pressure part of a vessel to which it is attached except austenitic stainless steel external welded attachments may be constructed from any 300-series stainless steel For purposes of establishing the attachment impact test requirements, the level of applied general primary membrane stress shall be considered to be the same as the maximum level applied to the pressure boundary component to which the external attachments are attached. 4.4 Examination, Inspection and Pressure Testing Welded Pressure Joint Requirements The welded pressure joint type and associated nondestructive examination requirements shall be specified on the PIP VEDV1003-F Welded Pressure Joint Requirements form Pneumatic Test Pneumatic testing should be considered for the following design cases: a. Large diameter vessels with low-pressure b. Vessels with exceptionally large volume c. Services that do not permit residual water in the process Process Industry Practices Page 18 of 24

21 d. Cases where great over design of the vessel and foundation are required only to support a water-full test The required detailed written procedures prepared by the Manufacturer for any pneumatic testing shall be reviewed and approved. The procedures shall be agreed with the User Because of the additional hazards of pneumatic testing, vessels shall be nondestructively examined to minimize the possibility of failure during the test. Additional nondestructive examination shall be considered for main seams, nozzle attachments, and some structural attachments. All nondestructive examination shall be specified on the PIP VEDV1003-D Data Sheet Acoustic emissions monitoring during pneumatic testing to locate flaws in the vessel shall be considered. If required, the acoustic emission monitoring procedures shall be specified on the PIP VEDV1003-D Data Sheet If Code Case 2055 is to be applied for any pneumatic testing, it shall be specified on the PIP VEDV1003-D Data Sheet Proof Test Proof tests (see Code Paragraph UG-101{not Div.2 applicable}) have unique requirements and are not included in this Practice. Process Industry Practices Page 19 of 24

22 Appendix A General Considerations for Pressure Relief Valve Application Process Industry Practices Page 20 of 24

23 Scope General Considerations for Pressure Relief Valve Application A general comparison of operational characteristics is given for direct spring and pilot-operated pressure relief valves in common industrial use. The influence on operating margin, from set pressure, is considered. General Operational characteristics of direct spring-operated and pilot-operated pressure relief valves should be understood by the User and the Purchaser. Direct spring and pilot-operated relief valves are available for use on applications that are required to meet Code requirements. Reseating Considerations The approximate reseating pressure for direct spring-operated valves is 93% of the set pressure in gas or vapor service and 85% of set pressure for National Board tested safety relief valves in liquid service. Many older liquid service safety valves, requiring 25% overpressure to be full open, have a reseating pressure as low as 70% of the set pressure. The reseating pressure for pilot-operated valves is typically specified in the same range as the direct spring valves. However, the reseating pressure of pilot-operated valves can be lowered to a value slightly above atmospheric by adding a manual blowdown connection which may be operated either locally or remotely. Pilot-operated valves are used in this fashion as remote, manual, emergency, blowdown valves. Service Limitations for Pilot-Operated Valves The versatile pilot-operated valve has some significant application limitations. Pilot-operated pressure relief valves are supplied with filters to protect against foreign matter and are generally recommended for relatively clean service. See Table A for a summary detailing when, and when not, to use pilotoperated valves. Table A. Recommended Application of Pilot-Operated Pressure Relief Valves USE Clean gas or vapor service Clean liquid service DO NOT USE Corrosion of wetted part is possible Polymerization process Coking service Abrasive or dirty service Freezing of contents at ambient temperature is possible Leakage Considerations The point where leakage begins to be a concern when using direct spring-operated valves depends on the disk seat design. Metal-to-metal contact seats will begin to leak at about 90% of set pressure. O-ring soft seat disk type direct spring-operated valves will not leak below 95% of set pressure. Pilot-operated valves do not leak below 98% of set pressure. The recommended maximum equipment operating pressure is slightly below, but frequently considered equal to, the start-to-leak limit for the valve. Process Industry Practices Page 21 of 24

24 Appendix B Commentary Process Industry Practices Page 22 of 24

25 This Appendix contains a commentary and other information on each of the paragraphs referenced at the beginning of each comment For example, if minimization of severely flammable or acutely toxic environmental hazards is a controlling design requirement, the establishment of a design pressure and associated Maximum Allowable Working Pressure (MAWP) that will provide containment without actuation of the pressure relief device may be a consideration. The margin is also dependent upon the operational characteristics of the pressure relief device. For example, if the maximum anticipated operating pressure of a gas/vapor service can be identified with confidence, and if metal-seated, direct spring-operated valves are specified, the design pressure is frequently established by dividing the maximum anticipated operating pressure by However, if a pilot-operated pressure relief device is used, the design pressure is sometimes established by dividing the maximum anticipated operating pressure by a factor as high as The establishment of the MDMT affects more than the operation of the equipment. Reliable administrative procedures to control the pressure/coincident temperatures during transient operations (e.g., startup and shutdown) are often appropriate from a materials-of-construction selection point-of-view. For example, if considering the effects of auto-refrigeration on carbon and low-alloy steels, such procedures make it appropriate to consider operations below the MDMT stamped on the nameplate, provided the reduction in MDMT for the coincident general primary membrane tensile stress results in a temperature that is no colder than that permitted in Code Paragraph UCS-66(b) { } Load conditions in addition to the default load conditions specified in PIP VESV1002 must be considered. Examples of additional load conditions are the new (uncorroded) hydrostatic test condition, a future (corroded) hydrostatic test condition including the desired coincident wind velocity, and other combinations that are required by the applicable building code at the installation site Vessels having inside diameters 3 feet (1 m) or less and subject to internal corrosion, erosion, or mechanical abrasion may justify the use of body flanges a. Hinged manways oriented with the nozzle neck axis in a horizontal plane may require special design details because of the danger of pinching extremities Hot hydrogen service is defined as hydrogen partial pressure greater than 100 psia (700 kpa-a), with a corresponding coincident temperature greater than 400ºF (205 C) Threaded connections must be used with caution because of the potential for crevice corrosion and notch sensitivity Leg supports used on vessels with agitators experience transient transverse forces because of dynamic bending moments from the agitator and sloshing of the liquid. Therefore, the design of leg-supported vessels with agitators requires the application of experience-based engineering judgment to ensure that displacement stiffness and stress levels essential to satisfactory operation are provided. Caution is advised for leg-supported vessels that may be within h/d 5 but could have excessive axial and/or bending loads on the legs or an overstress condition in the vessel wall. Process Industry Practices Page 23 of 24

26 The preferred skirt attachment detail shall be butt type (i.e., skirt butted to knuckle portion of head such that the centerlines of the skirt plate and the head flange are the same diameter, or such that the OD of the shell and the OD of the skirt coincide). Alternatively, a lapped type skirt design (i.e., skirt lapped to straight flange of head) may be used Environmental cracking of A-193-B7 anchor bolts can occur because of hydrogen from the corrosion process. For Stainless steel or other high alloy materials, possible chloride exposure and the metal yield strength should be considered Torch cutting or welding on zinc-plated, cadmium-plated, or hot dip galvanized bolts is known to generate toxic fumes. Use caution when cutting or welding on such bolts ASME guidelines for dual or multiple marking of materials are provided in Code Section II, Part D, Appendix 7. Under these ASME guidelines, dual or multiple marking signifies that the material so marked meets all of the requirements of all of the specifications, grades, classes, and types with which it is marked. Therefore, this means, for example, that the allowable stress values given in Code Section II, Part D for a regular grade of Type 304 stainless steel plate may be used in design for SA-240 plate material with a dual marking of Type 304/304L. Similarly, the rating for an SA-182 GR F304 B16.5 flange may be used if it is dual marked SA-182 GR F304/F304L Internal corrosion loss due to the process conditions affects all pressure-containing parts. Internal structural parts can experience corrosion loss on more than one surface. Bolted internal parts are frequently constructed of different materials and should be assessed separately External corrosion may result from exposure of bare metal to the atmosphere, especially in coastal areas and under insulation. Other equipment operating nearby may influence corrosion (e.g., cooling towers) Pneumatic testing can create extreme hazards to a facility and nearby personnel. See ASME PCC-2 Article 5.1 for guidance on energy calculations for pneumatic tests and safe distances for personnel during the test. Pneumatic testing should not be permitted unless hydrostatic testing is not reasonably feasible. See Code Paragraph UG-100 {8.3} and Code Paragraph UW-50 {Not Division 2 applicable}. Process Industry Practices Page 24 of 24