ASTM A531/A531M : 12

1.1 This practice covers ultrasonic examination of turbine-generator retaining rings produced in accordance with Specifications A288 and A289/A289M with an inside diameter to wall thickness ratio equal to or greater than 5:1 and with wall thicknesses from 1 to 4 in. [25 to 102 mm].

1.2 Forgings may be inspected by either the contact or the immersion methods, or combinations thereof, as agreed upon between the manufacturer and the purchaser.

1.3 Supplementary requirements of an optional nature are provided for use at the option of the purchaser. The supplementary requirements shall apply only when specified individually by the purchaser in the purchase order or contract.

1.4 This practice is expressed in inch-pound and SI units; however, unless the purchase order or contract specifies the applicable “M” specification designation (SI units), the inch-pound units shall apply. The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the practice, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the 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 and health practices and determine the applicability of regulatory limitations prior to use.