The NASA Pressure Vessels and Systems (PVS) Working Group developed updates to NASA-STD-8719.17, Requirements for Ground-Based Pressure Vessels and Pressurized Systems (PVS). With thousands of ground-based pressure systems across the agency storing substantial amounts of energy, it’s essential requirements for their safe and reliable operation remain current.
The PVS program updates its policies on an as needed basis, with document reviews typically occurring more frequently than the basic five year requirement. Recent updates include recommended qualifications for the Pressure System Manager (PSM) role; technical requirements, exclusions, and permissions; and revised and corrected editorial content.
A brief summary of current changes to the standard is provided below. If you desire information regarding prior history of the document, you can find it at the beginning of the Document History Log.
1.2.1 Applicability — The text of this section was modified to conform to current NASA practice on when and how a standard is used, particularly with respect to contracts, grants, and agreements.
2.0 Applicable Documents and Reference Documents — These sections were reformatted and updated to reflect actual usage within the standard and the current approach to structuring the document.
4.2.3.23 Excluded PVS — Added low pressure (less than 15 psig) Commercial Off-the-Shelf (COTS) portable cryogenic dewars to the list of components and systems that may potentially be excluded from PVS certification in accordance with NPD 8710.5, NASA Safety Policy for Pressure Vessels and Pressurized Systems, provided they are covered under appropriate inspection and maintenance programs, and meet the additional component specific requirements.
4.10.1.13 Pressure Relief Devices (PRDs) — Added requirements for PRDs on liquid withdrawal devices installed on low pressure COTS, portable non-Department of Transportation cryogenic dewars addressing
- Their inclusion in the PVS certification process
- How they should be installed
- How often they should be inspected, checked, and tested for functionality
4.10.4.7 Flexible Hoses — Added rejection criteria for wire braid reinforced flexible hoses; requiring removal from service of any flexible hose exhibiting major defects as classified in SAE ARP 1658.
4.10.9 Hydraulic Systems — Added a provision allowing hydraulic pump discharge pressure relief valves to be used as relief devices, provided specified flow requirements are met, functionality has been verified, and they are tested at no more than five year intervals to verify set point.
Appendix B — Added recommended minimum qualifications for the Center PSM position, including recommended education, experience, knowledge, abilities and a leadership background. This guidance is to help ensure the PSM possesses the capabilities needed to fulfill the responsibilities of the role.
Questions about the standard or suggestions for improvements may be addressed to Owen Greulich.