4.1 The sampling and inspection prescribed in this practice afford the purchaser a practical level of quality assurance on incoming material. They are based on cost/risk relationships considered typical for preformed thermal insulations offered for general use. In all cases, the purchaser should review this practice and determine its suitability in terms of his specific needs.

4.2 This procedure is intended primarily for the inspection of a continuing stream of lots, and there is not a high probability of rejecting occasional off lots. Consumer protection is based on economic pressure on the producer, through greater risk of lot rejection, to maintain the process average at 90 % conformance or better. Operating characteristic curves for the sampling plans employed can be found in Practice E2234, Table X-C through Table X-F.

4.3 It is not the intent of this procedure to estimate lot quality, control the quality of production, relieve the supplier of responsibility for the quality of material offered, or determine the disposition of material found to be defective after receipt by the purchaser.

1.1 This practice covers criteria for establishing the acceptability of lots of shipments of preformed board, preformed block and pipe, and batts and blanket thermal insulation based on sampling and inspection.

1.2 This practice is intended for use in conjunction with appropriate ASTM material specifications that classify and describe the specific physical requirements for the product in terms of qualification requirements and inspection requirements. Determination of nonconformity shall be based on the tolerances for individual sample test values prescribed in the material specification.

1.3 This practice may require inspection substantially different from that performed in the normal course of production. If the purchaser requires sampling and acceptance inspection in accordance with this practice, he shall so specify in the order or contract.

1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.5 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.