Status Report

NASA OIG Review of NASA’s Pressure Vessels and Pressurized Systems Program

By SpaceRef Editor
June 30, 2015
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NASA OIG Review of NASA’s Pressure Vessels and Pressurized Systems Program

Full Report


To conduct its space and science operations, NASA uses a variety of pressure vessels and pressurized systems (PVS) such as storage tanks, cylinders, and piping that deliver compressed gas or liquid under significant pressure. Because of the nature of these gasses and liquids and how they are used, PVS may fail and cause harm to people, facilities, and the surrounding environment if not properly operated and maintained. NASA has experienced PVS failures in the past that resulted in loss of mission, injury, and property damage.

As of February 2015, NASA managed 10,109 active PVS and spent approximately $22 million annually to inspect and maintain these critical systems. Most PVS failures occur when a vessel or piping wall fails or ruptures because the internal pressure of the material inside exceeds the strength of the wall. Similar to the skin of a balloon that progressively grows thinner as inflated and weaker after multiple inflation-deflation cycles, over-pressurization or repeated pressurization and depressurization can gradually weaken the skin or walls of PVS, eventually leading to failure. Internal or external corrosion and physical damage (scratches, dings, and dents) can also increase the risk of PVS failure.

We initiated this audit to determine whether NASA had implemented appropriate policies and procedures to protect lives and facilities while ensuring reliable operation of its PVS. As part of the review, we visited Glenn Research Center (Glenn), Kennedy Space Center (Kennedy), and Langley Research Center (Langley) to inspect PVS and interview Center Pressure System Managers (PSM) and other responsible personnel. We also gathered information from PSMs at other NASA Centers and facilities via an electronic survey.


NASA Centers could benefit from stronger oversight and clarification of policies and procedures to ensure reliable operation of their PVS, which in turn could reduce risk to personnel and facilities. Specifically, NASA policy and standards for the management, operation, inspection, and maintenance of PVS are intentionally written at a fairly high level and do not contain specific guidance regarding the application of national consensus codes and standards, and the level of experience, education, and training sufficient to qualify an individual to serve as a Center PSM. In addition, NASA’s Office of Safety and Mission Assurance (OSMA) did not provide adequate oversight of Center PVS Programs.

We also found multiple issues of concern at each of the Centers we visited, including corrosion on a large number of PVS, inadequate inventory and property controls, and unclear assignment of PSM roles and responsibilities. For example, at Langley we identified significant corrosion on high pressure piping and components, ground water penetration, and obstructed piping and systems in an underground utility corridor that contains high pressure steam piping, electrical conduit, and fiber optic communication lines (as shown in the figure). If a rupture were to occur in this corridor, the resulting damage could cause power and communication outages that would impact Center operations.

In our judgment, NASA’s PVS Program could be improved by establishing clear lines of communication for resolving issues, implementing corrosion prevention and mitigation programs, and evaluating and providing the PVS Programs sufficient resources to meet Center mission goals and objectives.


To improve NASA’s PVS Program and reduce the likelihood of mishaps, we made five recommendations to the Chief of OSMA, including (1) reviewing PVS management at all NASA Centers, (2) revising applicable NASA guidance, (3) reassessing the effectiveness of OSMA oversight, (4) requiring Centers to perform an analysis to determine if having certain calibration and repair capabilities on site would be cost and mission effective, and (5) requiring each Center to implement a formal PVS corrosion prevention and mitigation program. We also made recommendations to the Glenn, Kennedy, and Langley Center Directors to improve the overall effectiveness of each Center’s PVS Program.

In response to a draft of our report, management concurred or partially concurred with our recommendations and described corrective actions they plan to address them. We consider management’s comments responsive; therefore, the recommendations are resolved and will be closed upon completion and verification of the proposed corrective actions.

SpaceRef staff editor.