1.1 This specification covers electric fusion welded pipe suitable for high-temperature or corrosive service as listed in Table 1. (Although no restrictions are placed on the sizes of pipe that may be furnished under this specification, commercial practice is commonly limited to sizes not less than 8 in. [203 mm] nominal diameter.)

(A) Recommended temperatures—Different temperatures may be selected by either the purchaser or the manufacturer.
(B) Set temperatures, ±25°F [±14°C].
(C) Minimum set temperature.
(D) Registered Trademark of Haynes International.
(E) Heat treatment is highly dependent on intended service temperature — consult material manufacturer for specific heat treatments for end use temperature.
1.2 Five classes of pipe are covered as follows:

1.2.1 Class 1—Pipe shall be double welded by processes employing filler metal in all passes and shall be completely radiographed.

1.2.2 Class 2—Pipe shall be double welded by processes employing filler metal in all passes. No radiography is required.

1.2.3 Class 3—Pipe shall be single welded by processes employing filler metal in all passes and shall be completely radiographed.

1.2.4 Class 4—Same as Class 3 except that the weld pass exposed to the inside pipe surface may be made without the addition of filler metal.

1.2.5 Class 5—Pipe shall be double welded by processes employing filler metal in all passes and shall be spot radiographed.

1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. 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 non-conformance with the standard.

1.4 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 become familiar with all hazards including those identified in the appropriate Safety Data Sheet (SDS) for this product/material as provided by the manufacturer, to establish appropriate safety and health practices, and determine the applicability of regulatory limitations prior to use.