The gaskets covered by this practice can be used on, but are not limited to, equipment constructed of the following materials: (a) stoneware, (b) glass and glass-lined, (c) tantalum (solid and lined), (d) titanium (solid and lined or clad), (e) zirconium (solid and lined or clad), (f) silver (solid and lined), and (g) nickel and nickel alloys (solid and clad).

The gaskets provided for herein are for the following: (a) pipe flanges (flat or raised face), (b) vessel nozzles, (c) circular openings in vessels in excess of 12 in. (305 mm) diameter, and (d) oval openings in vessels.

1.1 This practice covers the designs, sizes, classifications, and construction of enveloped gaskets for severe corrosive applications. The envelope serves as the corrosion resistant member of the composite gasket and is a nonmetallic material such as polytetrafluoroethylene, PTFE, or related materials. The inserts are nonmetallic gasketing materials with or without metal reinforcement. Other types of composite gaskets are covered in Classification F 868.

1.2 This standard is based directly upon ANSI B16.21–1992; for that reason units are as ANSI stated in inches.

1.3 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.