4.1 This standard is intended to be used by engineers and designers as a guide to assist them in selecting appropriate thermal insulation jacketing materials. As a guide, it can be used to identify performance characteristics that might be necessary for a particular insulation jacketing system. This guide is not a specification and therefore should not be used as such. It might, however, be useful in writing a specification. Specification C921 can also be used to determine properties of jacketing materials for thermal insulation.

1.1 This guide covers criteria for selecting thermal insulation jacketing materials and is not intended for use as a performance or product specification.

1.2 This guide applies to jacketing materials applied over thermal insulation for piping, ducts, and equipment.

1.3 This guide includes jacketing materials used over thermal insulation whether the insulation is in the form of pipe, board, or blanket, or field applied materials that are self-supporting, including insulating cements.

1.4 This guide does not include covers or other retaining walls that contain loose fill, other nonsupporting insulation materials, or conduits or containers for buried insulation systems.

1.5 This guide does not include mastics and coatings and their reinforcements.

1.6 The values stated in inch-pound units are to be regarded as the standard. The SI values given in parentheses are provided for information only.

1.7 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 and health practices and determine the applicability of regulatory limitations prior to use.