scope:

This specification establishes surface cleanliness requirements for oxygen, fuel, and pneumatic components used in space vehicle fluid systems and associated ground support equipment (GSE) and test facilities. This specification is not intended to specify cleanliness requirements for composite surfaces used in cryogenic service, but it may be used to specify internal cleanliness requirements for metal-lined composite over-wrapped pressure vessels (COPVs). General cleaning requirements, verification procedures, drying and packaging requirements are provided. Each user shall require sub-tier documents to address processing, system cleanliness, solvent selection, cleanliness verification, and maintenance. An engineering assessment shall be necessary to establish requirements for each system.

Cleanliness Levels

Cleanliness levels for particulate and nonvolatile residue (NVR) are listed in Table I. Unless otherwise specified, the minimum cleanliness levels for new or re-cleaned systems, subsystems and components are specified in paragraph 3.2.3 and Table II.

Alternate Procedures

Methods and procedures other than those enumerated in this document may be utilized with prior approval of the NASA procuring activity.

This document applies the following: all mandatory actions (i.e., requirements) are denoted by statements containing the term "shall." The following terms also apply: "may" or "can" denote discretionary privilege or permission, "should" denotes a good practice and is recommended, but not required; "will" denotes expected outcome, and "are/is" denotes descriptive material.

Alternate Cleanliness Levels

For system performance or safety, some propulsion systems, such as hypergolic systems, may require cleanliness levels more stringent than those defined in Table I. When cleanliness levels more stringent than those shown in Table 1 are required they may be specified on the engineering drawing or specification in accordance with IEST-STD-CC1246, or particulate levels tailored from IEST-STD-CC1246, with cleaning, inspection, and packaging in accordance with this document. When a cleanliness level is required that cannot be defined by one of these specifications, the cleanliness requirement may be explicitly specified on the engineering drawing or specification as a custom cleanliness level. The custom cleanliness level shall state the maximum number of particles allowed per 0.1 m2 in defined particle size ranges.