This specification covers the general requirements for materials used in rubber seals of concentrating solar collectors. Design requirement pertains only to permissible deflections of the rubber during thermal expansion or contraction of the seal in use and the tolerances in dimensions of molded and extruded seals. The materials shall be classified according to usage: Type C and Type W; according to degrees of hardness: Grade 2; 3; 4; 5; 6; 7; and 8. The seals shall be classified as: Class PS and Class SC. Desert outdoor exposure and xenon arc laboratory exposure shall be performed to determine the resistance to solar radiation. The following test methods shall be performed: ultimate elongation; compression set; resistance to heating; resistance to ozone; resistance to low temperature; and adhesion loss.

1.1 This specification covers the general requirements for materials used in rubber seals of concentrating solar collectors. Particular applications may necessitate other requirements that would take precedence over these requirements when specified.

1.2 Design requirement pertains only to permissible deflections of the rubber during thermal expansion or contraction of the seal in use and the tolerances in dimensions of molded and extruded seals.

1.3 This specification does not include requirements pertaining to the fabrication or installation of the seals.

1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5 The following safety hazards caveat pertains only to the test methods portion, Section 9, of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.