Update Feb. 1, 2021: NPD 8710.5, NASA Safety Policy for Pressure Vessels and Pressurized Systems was cancelled on Feb. 2, 2021. The current directive is NPR 8715.1, NASA Hazardous Chemical Storage Requirements.
Updates to American National Standards Institute (ANSI)/American Institute of Aeronautics and Astronautics (AIAA) S-080A, Space Systems—Metallic Pressure Vessels, Pressurized Structures, and Pressure Components and ANSI/AIAA S-081B, Space Systems—Composite Overwrapped Pressure Vessels went into effect March 2018.
After more than 10 years of meetings, negotiations and edits between NASA, other Governmental Agencies, and private manufacturing companies, the two aerospace pressure vessel and component performance standards were reorganized to make navigating the documents and finding specific requirements easier, and to more accurately reflect current industry practice. The updated standards define specifically what kinds of processes need to be used and how compliance validation must be performed.
The following changes were made to the revised versions of both ANSI/AIAA S-080A and ANSI/AIAA S-081B:
- Updated the requirements for design and verification, including damage tolerance life (formerly referred to as safe life) and leak before burst
- Articulated the responsibility of the owner, manufacturer and procuring authority
- Organized the requirements into separate sections for design, analysis and test
- Added a design requirements verification matrix
- Added sections to identify the manufacturing, Quality Assurance, and operations and maintenance requirements
- Added requirements for maximum mass and required volume
- Added requirements for quantifiable Reliability and a Failure Modes and Effects Analysis
- Identified requirements associated with reuse
- Articulated requirements for data documentation
- Incorporated loading spectra into the service life
Both standards also were updated to assure alignment between them.
ANSI/AIAA S-080A
ANSI/AIAA S-080A, Space Systems—Metallic Pressure Vessels, Pressurized Structures, and Pressure Components establishes baseline requirements for the design, analysis, fabrication, test, operation and maintenance of metallic pressure vessels; pressurized structures; batteries; heat pipes; cryostats; dewars; sealed containers; accumulators; and pressure components such as lines, fittings, hoses, and bellows made of metals. These components are used for pressurized, hazardous or nonhazardous liquid or gas storage in space systems including spacecraft and launch vehicles.
In addition to the changes indicated above to both documents, the following changes were applied to ANSI/AIAA S-080A:
- Expanded the requirements for stability and included a higher safety factor when verification is performed by analysis only
- Added requirements to address scenarios with significant combined loads
- Added an alternate set of requirements for lines and/or fittings with 1.5 inches (38 millimeter) outside diameter or greater
- Aligned sections to better identify the separate requirements for metallic pressure vessels; pressurized structures; batteries; heat pipes; cryostats; dewars; sealed containers; and pressure components such as lines, fittings, and hoses made of metal
- Removed the thermal vacuum testing requirement for batteries and battery cases (because they will be included in ANSI/AIAA S-136-201x, Battery Safety Standard for Space Applications)
ANSI/AIAA S-081B
ANSI/AIAA S-081B, Space Systems—Composite Overwrapped Pressure Vessels establishes baseline requirements for the design, analysis, fabrication, test, inspection, operation and maintenance of Composite Overwrapped Pressure Vessels (COPVs). These COPVs are used for pressurized, hazardous or nonhazardous liquid or gas storage in space systems including spacecraft and launch vehicles. This standard is applicable to COPVs constructed with a metal liner and a carbon fiber/polymer overwrap.
In addition to the changes indicated above to both documents, the following changes were applied to ANSI/AIAA S-081B:
- Expanded the requirements for stability
- Added references to American Society for Testing and Materials standards for inspection
NPD 8710.5, NASA Safety Policy for Pressure Vessels and Pressurized Systems is currently in review with changes to reflect the updated ANSI/AIAA standards.
Questions can be directed to PVS Program Manager Owen Greulich.