Chapter 14 Table of Contents. View the entire chapter in a PDF format. Please use the pdf for printing.

Requirements:
General (5.1)

This section contains general requirements for pressure system design and modification, fabrication, installation, testing, inspection, operation, maintenance, service, repair, and decommissioning. Following these requirements keeps SLAC in regulatory compliance and ensures that all work pertaining to pressure systems is conducted in a manner that protects workers and the environment from recognized hazards.

Note: The term pressure system refers to all types of systems within the scope of this chapter: pressure, vacuum, and cryogenic systems for both conventional and science applications.

Design and Modification (5.1.1)

All pressure systems and components or hardware must be designed in strict adherence to the following safety objectives and requirements and all applicable codes and standards. The design process must be fully documented and any design that cannot meet applicable codes and standards must undergo additional levels of review as specified.

Legacy Systems (5.1.1.1)

A legacy system is any pressure system installed before May 25, 2007. Legacy systems must only be brought into compliance with the requirements for new systems (Section 5.1.1.2, “New Systems”) under the following conditions.

• If an addition to or modification of a legacy pressure, cryogenic, or vacuum system affects more than 10 percent of the existing system, it must be brought in compliance with 10 CFR 851. Changes that do not affect a legacy system more than 10 percent must meet the codes, regulations, and work smart standards, including those associated with maintenance and operation, in effect at the time that system was installed.
• 10 CFR 851 levies an overarching requirement that all workplaces be free from recognized hazards that can cause or have the potential to cause serious physical harm to workers. This requirement dovetails with the SLAC Integrated Safety and Environmental Management System (ISEMS). In meeting these safety objectives, any legacy pressure system that is determined to carry a serious hazard potential for workers who use, service, maintain, or repair those systems must have the appropriate safety controls in place. The safety controls must be consistent with the letter and intent of current codes, regulations, work smart standards, and laboratory safety policies as described in the following sections.

New Systems (5.1.1.2)

The design requirements applicable to all new pressure systems and any legacy systems undergoing significant change (as described in the previous section) are the following.

• Hazard analysis. Pressure systems must be designed so that no single point failure in the system will result in a severe injury, significant environmental impact, or potential loss of a facility. The use of process hazard analysis should be used to assess the risk and the controls that will eliminate single point failure designs.
• Design safety factor. Any design for an application that calls for a component or system that falls outside applicable codes or standards must provide a level of protection greater than or equal to the level of protection provided by the code. A safety factor of 4 times (4x) the design burst pressure over the maximum allowable working pressure (MAWP) is a good guideline unless another safety factor is approved by the Hazardous Experimental Equipment Committee (HEEC) in consideration of the administrative controls, training, area of use, duration of use, functionality, materials, and science objective of the project.
• Design for safe use. Pressure systems must be designed and installed with full consideration of the end user's ability to operate the system safely, and, the operation of the system must not create uncontrolled safety risks to the overall workplace environment.
• Design for safe maintenance, servicing, and repair. Pressure systems must be designed (and installed) with full consideration of the safety of the person who will perform maintenance, service, and repair. Design considerations include proper placement of components for servicing, providing means and methods for controlling hazardous energy, and taking into account human factors.
• Design for the environment of use. If installed indoors, mechanical exhaust ventilation may be required. If placed outdoors, the system may need additional protection from direct sunlight, corrosion, physical impact, and/or other environmental factors.
• Design for natural hazards. Pressure systems must be designed with consideration of natural hazards such as earthquakes, wind, rain, and temperature extremes in order to ensure safety, business/science continuity, and business recovery.
• Design for safe manufacture. Hazards associated with the installation and manufacture of the system should be identified during the design phase.

For additional detail, see Pressure, Vacuum, and Cryogenic Systems: Design Requirements [pdf]. For guidance on vacuum systems, see Vacuum Systems Consensus Guideline for Department of Energy Accelerator Laboratories and Pressure, Vacuum, and Cryogenic Systems: Vacuum System Requirements [pdf].

Design Documentation (5.1.1.3)

The design documentation for any pressure vessel or pressure system design must include the following.

• The project scope and applicable codes and standards: if the project scope includes equipment that is outside the code, best alternative engineering practices must be specifically identified.
• Hazards and engineering controls: documentation must fully describe operating pressures and the size and specifications of safety-related equipment such as relief valves and emergency shut-offs.
• Construction and piping fabrication plans: plans must include all drawings - plan view, isometric, and piping and instrumentation diagrams (P&ID) - and specifications for fabrication or manufacturing, testing, installation, operation, and maintenance. The plans must also include any essential intermediate steps (for instance, checking for vacuum leaks in a thin-walled ceramic beam pipe prior to installing it in a kicker system).

Safety Review (5.1.1.4)

The level of safety oversight for the various types of systems, based on the intended application and the hazards presented by system specifications, are listed below.

• All pressure vessels. A review and approval by the pressure vessel registration manager is mandatory except for the following vessel types: any ASME "U" or "UM" stamped vessel, DOT-approved cylinders, and dewars used as the pressure source. For registration details and the Mechanical Engineering Safety Inspection (MESI) form, see Pressure, Vacuum, and Cryogenic Systems: Pressure Vessel Registration Form (MESI) [pdf].
• Conventional applications. A safety review and oversight is mandatory for all projects and is the responsibility of line management and the project engineer.
• All construction projects must be submitted to the Environment, Safety, and Health (ES&H) Building Inspection Office (on the Resource List [pdf]) prior to submitting the project to the Purchasing Department.
• Conventional applications that may require HEEC review include instances in which a design presents an unusual combination of hazards, or in instances in which the installation presents unusual hazards. These could be due to, for example, equipment placement or location.

• Science applications. A safety review and oversight by line management and the project engineer is mandatory for all projects, and in addition, approval by the HEEC is mandatory as described in Pressure, Vacuum, and Cryogenic Systems: HEEC Review Requirements [pdf].

Procurement (5.1.2)

All pressure system components must meet the applicable code requirements identified in the design phase. Line management and project managers must ensure that all selected components are traceable to the applicable code(s) through certifications or statements made by a manufacturer, vendor or supplier in product catalogs, product literature or cut sheets. Documentation to verify this must be retained as part of the design package for audit purposes.

Fabrication (5.1.3)

Fabrication methods must meet applicable codes for piping systems and pressure vessels where applicable codes exist. (See the appropriate applicable ASME standard.) Small-scale, low-pressure scientific pressure systems must be fabricated in accordance with the best practices applicable for the specific system type. Some low-pressure, low-hazard systems may use standard pressure fittings for such applications.

Pressure Vessel Registration (5.1.4)

All pressure vessels, once approved, must be registered with the pressure vessel registration manager to be added to a master list. (The only exception applies to vacuum vessels that qualify as "inherently safe" in that they are classified as category I or II systems in Pressure, Vacuum, and Cryogenic Systems: Vacuum System Requirements [pdf].)

The project manager or a designated person must submit to the pressure vessel registration manager a completed pressure vessel registration form [pdf] for any vessel that is new, re-used, or modified. This requirement applies to both conventional and science applications. In addition, all relevant information (design, fabrication, pressure test, and/or operating procedures) must be included.

Installation and Inspection (5.1.5)

Line management and the project manager must ensure that all pressure systems are installed in accordance with all applicable codes or regulations and in the manner stated in the approved design documentation. Inspection requirements during installation include

• Oversight by line management and the project manager to ensure that all requirements are being met
• A verification of the installation of appropriate control of hazardous energy isolating devices or features

Piping Systems (5.1.5.1)

Piping must be labeled in accordance with ASME/ANSI A13.1 requirements, which requires that markings

• Consist of the content's name and include a direction of flow arrow
• Are provided at each valve; at wall, floor or ceiling penetrations; at each change of direction; and at a minimum of every 20 ft throughout the piping run*

* ASME A13.1-2007, “Scheme for the Identification of Piping Systems”, Section 3.1, “Legend”. See the “SLAC Research Library Community Pages”, for available standards.

Testing (5.1.6)

All systems must be tested for leaks and workmanship quality prior to commissioning the system as follows. Test results must be documented and maintained. Pressure systems must be proof-tested and pressure/vacuum leak tested in accordance with all regulatory or code requirements or as required in the approved design documentation.

Operational Approval and Safety (5.1.7)

For conventional applications, line management and/or project engineers must determine when an installation is ready for use given that all requirements have been satisfied and the system is safe to use.

For science applications, a current operational approval from HEEC must be on record.

Line management, project engineers, or other persons of authority must not place any system into operation without assuring that all persons who will operate, maintain, service or repair such systems have had the appropriate level of training and are authorized to perform such work.

Use (5.1.8)

Line management is responsible for ensuring that pressure system users have completed the appropriate level of training commensurate with the user's level of interaction with or responsibility for the system. For instance, a "user only" would require different training from an equipment custodian who maintains, services, or repairs the system.

Line management is responsible for ensuring that written procedures are in place for operating pressure, cryogenic, or vacuum systems and line management is also responsible for determining the required level of detail.

Maintenance, Service, and Repair (5.1.9)

Maintenance (5.1.9.1)

All pressure systems must have a comprehensive maintenance plan that keeps the work environment safe, and the plan must be in place from the first day the system is placed in operation. Maintenance refers to the performance of scheduled measures such as calibration, soft-goods replacements, refurbishment, and corrosion protection. Maintenance must be performed on a planned or time-compliant basis by properly trained personnel.

Maintenance Plan Elements

The equipment owner determines the elements that will constitute the maintenance program based on the risks a particular pressure system poses. Common maintenance plan elements include:

• A written maintenance plan provided by the system owner that lists
• Maintenance activities and procedures
• Maintenance intervals
• Maintenance personnel qualification requirements

• Identification of qualified maintenance personnel. Maintenance may be performed by a qualified person or a qualified group, such as the Facilities Department or a vendor.
• The identified maintenance group must be provided with all necessary documentation and procedures. Note: The group may refuse to accept the (sub-) system for such deficiencies as insufficient documentation, understaffing, or lack of required expertise.

• An up-to-date log of maintenance activities
• Inspections

Performing Maintenance Safely

In performing maintenance on pressure systems, the following is required:

• Hazardous energy isolating devices must be available to allow affected workers to isolate the system from hazardous energy to allow safe maintenance in accordance with Control of Hazardous Energy program requirements.
• Any maintenance that involves breaking the pressure boundary integrity requires that the system or system section must be pressure/leak tested or vacuum/ leak tested at the MOP or MAWP to verify workmanship. Pressure testing must be accomplished with an inert fluid if the system is designed to handle hazardous materials.
• When venting or purging a beamline vacuum system, it is imperative that the gas source is equipped with an integrated relief device (such as a low-pressure relief valve) to avoid pressurizing the system above a safe pressure.

Servicing (5.1.9.2)

Servicing refers to activities needed to replace or replenish materials that are used up, consumed, or worn out. Examples include the replacement of filters, hydraulic fluid, and lubricants such as compressor oil. Generally, less extensive training is required for equipment service than for equipment maintenance.

The location where service work must be accomplished must be readily accessible and there must be enough workspace available to perform the work safely.

Repair (5.1.9.3)

Repairs and/or modifications to vessels, tanks, piping, and other components must be performed to the same standards, codes, and requirements as new systems and components. Repairs to other parts of the pressure system must be as good as the originally installed equipment or be brought up to the appropriate safety level and be consistent with the following requirements.

Once the repair is finished and the system is reassembled, the system must be pressure tested according to the requirements specified in the applicable codes or regulations. In the absence of specific testing requirements, these general rules apply:

• Any pressure system or system component, including fittings or welds that have been repaired, modified, or possibly damaged, subsequent to having been hydrostatically tested, must be retested hydrostatically to 1.5 times the MAWP or pneumatically tested to 1.1 times the MAWP prior to reuse. Replacement of gaskets, seals, and valve seats that do not affect the structural integrity may only require a leak test.
• After pressure testing, modified or repaired pneumatic systems must be leak tested at the system MOP prior to placing them back in service.
• After pressure testing, modified or repaired pneumatic systems must be functionally tested at the system MOP prior to reuse.
• All pneumatic system mechanical joints affected in the disconnection, connection, or replacement of components must be leak tested at the system MOP before being placed back in service. The method of leak testing may include pressure decay, soap bubble, or helium leak testing.

Decommissioning (5.1.10)

Any pressure system or component that is removed from service must be protected from unintentional operation and must be rendered safe, as applicable:

• If the pressure vessel is registered with the pressure vessel registration manager, the change in vessel status must be reported to the pressure vessel registration manager.
• Any pressure system that is defective or unsafe for reuse must be labeled or rendered unusable by, for example, dismantling or disposal.
• Potential pressure hazards must be identified and mitigated.
• Valves connecting the system to other systems must be closed, locked-out, and tagged, or the decommissioned system may be completely disconnected from other systems.
• The system may be disassembled.

Asset Preservation (5.1.10.1)

Pressure systems intended for reuse must be protected from damage or degradation. This may include measures such as backfilling with nitrogen to protect against corrosion.

If the vessel or system is to be stored in place, it must be clearly labeled with the following information:

• Equipment owner and department or division
• Current date
• Last date of operation and system content
• Condition (serviceable or defective, including details)
• Detailed information on potential hazards (contamination, danger)

Disposal of Assets or System Content (5.1.10.2)

System components or content must be removed in coordination with the following subject matter experts or departments:

• Any system that contains or is contaminated with a hazardous material. A decommissioning plan must be submitted to ES&H (Hazardous Materials and Air Quality Group) at least 60 days before decommissioning is scheduled to begin.
• System content must be emptied in a controlled manner. This can be accomplished by a chemical supply vendor, who may reclaim unused product, or by the equipment owner. All waste must be properly disposed of:
• Venting of gas must be done in accordance with applicable regulatory requirements provided by the air quality program manager.
• Liquid or solid content must be disposed of by coordinating with the Waste Management Group.

• To arrange for removal of conventional systems and components, contact the Salvage Department in Business Services.
• For removal of contaminated systems or larger items, contact the Waste Management Group.

continue to Requirements, Roles & Responsibilities (5.1.11)