This specification establishes the general requirements for two types, two classes, and seven grades of rubber seals used in solar energy systems employing air-heat transport, such as duct and damper seals. Particular applications may necessitate other requirements that would take precedence over these requirements when specified. The design requirement stated herein 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. This specification does not address the requirements pertaining to the fabrication or installation of the seals. Type C seals are intended for use in cold climates, while Type W seals are intended for use in warm climates. Grade designations (Grades 2 to 8) represent differing degrees of hardness. Finally, Class PS are preformed rubber seals, while Class SC are sealing compounds. Each class shall conform to individually specified values of the following requirements: ultimate elongation; compression set at specified times and temperatures; resistance to heating (hardness and ultimate elongation change, and volatiles lost); resistance to ozone; resistance to low temperature; and adhesion loss.

1.1 This specification covers the general requirements for the rubber seals used in solar energy systems employing air-heat transport. Examples are duct and damper seals. Particular applications may necessitate other requirements that would take precedence over these requirements when specified.

Note 1: Rubber seals for the collector are covered in Specifications D3667 and D3771.

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 10, of this specification: This standard does not purport to address the safety concerns associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.