This guide includes recommendations for inservice inspection and recertification of ground based, unfired pressure vessels and all pressurized systems including those served by fired pressure vessels hereinafter referred to as pressure vessels, systems, and components of systems.

It covers the vast array of ground based industrial and special purpose pressurized components and systems used at NASA Centers for research and development and those utility systems and components that require more than routine maintenance to insure continued structural integrity for their useful life. Through surveillance and correction of inservice deterioration, NASA will maintain a safe working environment for their own and contractor personnel, safety for the public sector, and protection against loss of capital investment.

Items excluded from this guide are defined in Chapter 2.

Coverage includes test methods, system and component categorization, recertification procedures and documentation, and inservice inspection to support and maintain certification status. Recommended documentation forms are included in Appendix A.

THIS GUIDE DOES NOT REPLACE EXISTING ROUTINE OPERATIONS AND MAINTENANCE INSPECTIONS. System and component checks must be made on a continuing systematic basis at the beginning of each shift, periodically during runs, weekly or at other intervals of time, based on service history and criticality. Such checks are normally visual and audible to evaluate changes related to vibration or gas leaks, checks of instrumentation, etc., for indications of potential failures. Protective coatings on pressurized components must also be maintained on a continuing basis.

This guide is highly dependent on application by qualified pressure systems engineers and NASA-wide uniform application is dependent on good communications among the NASA Centers.

PURPOSE

a. This NPG is published for the purpose of establishing an outline of inservice inspection and recertification procedures for ground based, unfired pressure vessels and systems. It shall not replace the normal routine repair and maintenance programs now in effect.

b. Recommendations for categorizing systems and components, baseline inspection and recertification time intervals are presented in tabular form and a type and format of documentation is recommended.

APPLICABILITY

It is intended that each NASA Center use this guide and other applicable documents to define the detailed requirements and procedures for the specific vessels and systems over which it has cognizance.