|
Pressure and Vacuum Systems Safety Supplement Part
5: Repair and Alteration |
|
|
|
|
Repairs and alterations of all pressure systems and components, regardless of initial fabrication or design date, shall be performed by qualified personnel under the direction of the DA assigned to the specific task. Repairs and alterations shall be performed in compliance with the requirements of this section. Jefferson Lab shall not assume the duties of the fabricator or inspector for repairs or alterations of the pressure boundary on an ASME Pressure Vessel. All personnel directly involved in the repair or alteration of a pressure system onsite shall meet the requirements given in Part 1: Section 1.4.5 Pressure System and Test Technicians.
Below is a list of the Codes possibly applicable to Jefferson Lab pressure system repair and alteration. Included are brief descriptions of where these Codes may be applicable.
· ASME Boiler and Pressure Vessel Code
o Section II: Specifications for materials including tables of allowable stresses.
o Section V: Requirements and methods for non-destructive testing
o Section VIII: Rules for construction of pressure vessels. This Section is split into 3 divisions. Division 1 is the standard set of rules. Division 2 is alternative rules where more detailed analysis is required but, lower factors of safety are required. Division 3 consists of rules for high pressure vessels.
o Section IX: Welding and Brazing Qualifications
· National Board Inspection Code (NBIC) / NB-23
o Part 1: Installation
o Part 2: Inspection
o Part 3: Repair and Alteration
o Part 4: Pressure Relief Devices
· ASME B31 Code for Pressure Piping
o B31.1 Power Piping: applicable to piping generally found in electric power production and district heating plants
o B31.3 Process Piping: General piping code most applicable for piping systems at Jefferson Lab not associated with building services.
o B31.4 Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids
o B31.5 Refrigeration Piping and Heat Transfer Components: Applicable to HVAC systems.
o B31.8 Gas Transmission and Distribution Piping Systems
o B31.9 Building Services: Applicable to piping carrying nonhazardous fluids at moderate temperatures typical in building services such as hot and cold water as well as instrument air systems.
o B31.11 Slurry Transportation Piping Systems
o B31.12 Hydrogen Piping and Pipelines
o B31E Standard for the Seismic Design and Retrofit of Above-Ground Piping Systems
· ASME PCC-2 Repair of Pressure Equipment and Piping
Pressure-Relieving Devices:
· American Petroleum Institute (API)
o API 520:Sizing, Selection, and Installation of Pressure-Relieving Devices in Refineries applies to the sizing and selection of pressure relief devices used in refineries and related and gives excellent guidance for selecting relief devices
o API 521: Guide for Pressure-relieving and Depressuring Systems. This Code gives guidance for determining the causes of overpressure and mitigating measures that can be taken.
A repair of an existing pressure system shall be defined as any work performed on an existing system that is not considered maintenance (see Part 8: Section 8.2 Maintenance) and does not change the fluid service or any aspect of the original design specifications. A repair of any pressure system component installed on an existing system shall either return this component to its original specifications or replace it with a new component with equivalent specifications.
Repairs or replacement of components not larger than NPS 5 (DIN 125) that do not require welding, brazing, or other hot work may be considered routine in nature and are considered in Part 8: Section 8.2 Maintenance.
An alteration of an existing pressure system shall be defined as any work performed on an existing system that may change any aspect of the design specification or fluid service; this includes changes to the structural supports for piping or vessels and extension of piping.
Repairs or alterations to Excluded Vessels (i.e. those without an ASME stamp) shall be performed in accordance with Part 5: Section 5.4 Repair and Alteration Procedures.
Repairs or alterations to ASME Pressure Vessels, excluding those not affecting the pressure resisting components (i.e. the pressure boundary), shall be performed by an organization that is authorized to use the National Board R stamp. These repairs or alterations to pressure vessels shall be coordinated by the Facilities Management and Logistics Department.
Repairs or alterations to “ASME”, “V”, “UV”, “HV”, “UV3”, “TV”, or NBIC “VR” stamped pressure relief devices shall be performed by an organization that is authorized to use the National Board “VR” stamp. All other relief devices with set pressures greater than 15 psi requiring repair shall be replaced with Code compliant devices.
Repairs and alterations to pressure systems must be completed under the direction of the DA and be properly documented as described in Part 1: Section 1.5 Required Documentation.
Repairs to piping components and Excluded Vessels installed on a pressure system shall comply with the original construction Code, NBIC (Part 3), ASME PCC-2, or other suitable post construction code. Where the original Code is unknown and the DA chooses not to use NBIC or PCC-2, the most applicable ASME Pressure Code in effect at the time of repair shall be used. Where ASME Pressure Codes do not apply, sound engineering principles and equivalent measures as described in Part 3: Equivalent Measures shall be used.
All alterations to pressure systems shall be completed under the direction of an assigned DA. Where an ASME Pressure Code applies, all design and fabrication of the alteration and tie in to the existing system, shall be performed to the Code edition (year) in effect at the time of the alteration. Applicable Codes may be construction codes (e.g. ASME B31.3, ASME B31.9, ASME B31.12, etc.) or post construction codes such as ASME PCC-2 or NBIC Part 3. Where Codes do not apply, sound engineering principles and equivalent measures as described in Part 3: Equivalent Measures shall be used. When performing any alteration the DA shall at least consider the following:
· Changes to design temperature and the effect on materials.
· Changes to design pressure may have multiple affects. Relief device set points and capacities may be affected. Relief paths may not be adequate for new requirements. While the original wall thicknesses may be adequate, corrosion effects may require reduced operating pressures.
· Tie-ins to existing systems:
o The DA shall fully understand the upstream operating conditions
§ Design pressure/temperatures
§ Fluid service
§ Relief capacities
§ Method of tie-in and reaction loads
o The DA shall ensure that adequate relief capacity is installed on the system
· Flow paths and changes to relief paths as these may affect pressures and reaction loads.
· Changes in fluid service as these may affect live loads, pressures, operating temperatures, relief capacities, corrosion allowance, etc.
· Seismic, wind, and other loads as given in ASCE 7
Repairs and alterations do not require a system wide pressure test or inspection. The extent of the test and inspection requirements shall be determined by the DA.
Repairs to any pressure component or branch (i.e. pressure boundary) of a system that is energized shall be categorized as follows:
Case 1: Repairs to a component or branch that has been isolated by valve lineup or system configuration (e.g. blank flanges, etc.) and locally deenergized; meaning part of the system unaffected by the repair remains energized.
Case 2: Repairs to components that are fully or partially energized.
The component or branch of the system to be repaired shall be isolated, as given in Case 1 above, provided that this does not cause an unacceptable service interruption or create an unsafe condition.
Repairs to components not retaining pressure (e.g. piping supports, hanger, etc.) on energized systems may be performed when the system integrity, personnel and equipment safety is assured through appropriate procedures and review, as determined by the DA.
Repairs shall be affected as follows:
Case 1:
· An OSP or TOSP detailing the system configuration and preparation prior to and following the repair as well as the repair procedure itself shall be written by or approved by the DA in addition to normal procedural signoffs
· If the system fluid is flammable, Category M as defined by ASME B31.3, or considered hazardous by the ES&H manual then the isolated component or branch of the system shall be purged by an inert fluid prior to any repair. The procedure for purging shall be included in the OSP or TOSP.
Case 2:
· An OSP or TOSP detailing the system configuration and preparation prior to and following the repair as well as the repair procedure itself shall be written by or approved by the DA in addition to normal procedural signoffs.
Standard work planning tools (i.e. THA, Atlis, TOSP, AHA, etc.) shall be written to ensure personnel and equipment safety. These documents shall describe any required system configuration and preparation prior to and following the repair as well as the repair procedure itself (if required).
If the system fluid is flammable, Category M as defined by ASME B31.3, or considered hazardous by the ES&H manual then the system must be purged by an inert fluid prior to any repair.
Alterations to any pressure component or branch (i.e. pressure boundary) of a system that is energized shall be categorized as follows:
Case 1: Alterations to a component or branch that has been isolated by valve lineup or system configuration (e.g. blank flanges, etc.) and locally deenergized; meaning part of the system unaffected by the alteration remains energized.
Case 2: Alterations to components that are fully or partially energized.
The component or branch of the system to be altered shall be isolated, as given in Case 1 above, provided that this does not cause an unacceptable service interruption or create an unsafe condition.
Alterations to components not retaining pressure (e.g. piping supports, hanger, etc.) on energized systems may be performed when the system integrity, personnel and equipment safety is assured through appropriate procedures and review, as determined by the DA.
Alterations shall be affected as follows:
Case 1:
· An OSP or TOSP detailing the system configuration and preparation prior to and following the alteration as well as the alteration procedure itself shall be written by or approved by the DA in addition to normal procedural signoffs.
· If the system fluid is flammable, Category M as defined by ASME B31.3, or considered hazardous by the ES&H manual then the isolated component or branch of the system shall be purged by an inert fluid prior to any alteration. The procedure for purging shall be included in the OSP or TOSP.
Case 2:
· An OSP or TOSP detailing the system configuration and preparation prior to and following the alteration as well as the alteration procedure itself shall be written by or approved by the DA in addition to normal procedural signoffs.
· The DA shall provide detailed procedures in the OSP or TOSP to ensure personnel and equipment safety.
· Alterations to systems where the system fluid is Category M shall require written approval from the Jefferson Lab Director
· Hot Tapping:
o Hot tapping on systems where the system fluid is water shall require only the approvals included in the signoff of the associated OSP or TOSP.
o Hot tapping on systems where the applicable Code and fluid Category is B31.3 Category D (other than water), B31.5, or B31.9 and the piping is not larger than NPS 6 (DN 150) shall require only the approvals included in the signoff of the associated OSP or TOSP.
o All other hot tapping operations shall require written approval from the Jefferson Lab Director in addition to the approvals included in the signoff of the associated OSP or TOSP.
Standard work planning tools (i.e. THA, Atlis, TOSP, AHA, etc.) shall be written to ensure personnel and equipment safety. These documents shall describe any required system configuration and preparation prior to and following the alteration as well as the alteration procedure itself (if required).
If the system fluid is flammable, Category M as defined by ASME B31.3, or considered hazardous by the ES&H Manual, then the system must be purged by an inert fluid prior to any alteration of any pressure retaining components.
The DA shall determine the nature and extent of the calculations required for all pressure system repairs and alterations. These calculations shall be reviewed as required:
· A Technical Review shall be performed where the design of the repair or alteration meets ASME Pressure Codes, or NBIC.
· A Peer Review shall be performed where the design of the original or modified system component(s) cannot meet national consensus codes.
The extent of the calculations required shall depend on the nature of the repair or alteration. Calculations are required for all repairs and alterations requiring welding or brazing. Where piping repairs or repairs to Excluded Vessels are affected, calculations showing that the repair returns the component to original design requirements (or exceeds them) are required. Calculations for alterations and tie-ins to existing piping shall be the same as those for new construction (see Part 2: Section 2.4 Design). The DA shall determine the nature and extent of the calculations required.
Repairs and alterations requiring welding or brazing shall meet the additional requirements given in the Jefferson Lab Welding and Brazing Supplement (WBS). If the system fluid is flammable, Category M as defined by ASME B31.3 or considered hazardous by the ES&H Manual, the system shall be purged with an inert fluid and the purged condition shall be verified by acceptable detection methods prior to any hot work performed on the system.
Exception: “Hot Tapping” of pressure systems shall comply with Part 5 Section 5.4.3 Alterations to Energized Systems.
Repairs and alterations requiring welding or brazing shall meet the requirements for examination given in the applicable Code of construction or post construction. With the exception of Category M and High Pressure Piping (as defined in ASME B31.3), the DA responsible for the repair or alteration shall ensure that one or more of the following tests or examinations are performed. In the following list, where exclusive use of a certain method is prohibited, at least one other test or examination method shall be used.
o Test shall be as described in ASME B31 (relevant Section), ASME PCC-2, or NBIC Part 3
o Test shall be as described in ASME B31 (relevant Section), ASME PCC-2, or NBIC Part 3. Plastic and other piping subject to brittle failure such as PVC, CPVC, and PVDF shall not be pneumatically tested. See Part 6: Section 6.1 Pressure and Leak Testing.
o If the fluid service is Category D or Normal (as described in ASME B31.3) and not flammable, toxic, or harmful to humans or the environment or otherwise considered hazardous by ES&H Manual, then an initial service leak test may be performed. The exclusive use of this test is prohibited unless explicitly allowed by the original code of construction.
o A sensitive vacuum leak test may be performed. Exclusive use of this test is prohibited on all systems with a design pressure greater than 15 psi.
· Nondestructive examination:
o Nondestructive examinations in compliance with ASME BPVC Section V may be performed. These examinations may be performed instead of or in addition to the pressure tests described above. Exclusive use of the visual examination (VT) is prohibited on all components larger than NPS 5 (DIN 125).
The required examinations and testing shall be as given in the most recent edition of ASME B31.3.
The required examinations and testing shall be as given in the most recent edition of ASME B31.3.
Repairs and alterations requiring welding or brazing shall meet the requirements for inspection as given in the Welding and Brazing Supplement.
Documentation for each pressure system repair and/or alteration shall be as described in Part 1: Section 1.5.5 Folder Content.
Revision 1.1 – 01/10/19 - Updated
Section 5.1 to comply with January 2019 DOE revisions to 10 CFR 851.
Remove years associated with standards.
|
|
Issuing
Authority |
Supplement
Author |
Approval
Date |
Review
Date |
Rev. |
|
|
|||
|
QA/CI Dept. |
11/06/15 |
11/06/20 |
1.1 |
|
||||||
|
|
|||||||||