PIPING GUIDE: Variety of Standards Used in Design and Selection of Flanges

There are a variety of standards used in the design and selection of flanges. The following codes and standards relate to pipe flanges:

B16.1 - Cast Iron Flanges and Flanged Fittings
B16.5 - Pipe Flanges and Flanged Fittings
B16.24 - Bronze Flanges and Fittings–150 and 300 Classes

B16.42 - Ductile Iron Pipe Flanges and Flanged Fittings–150 and 300 Classes

B16.47 - Large Diameter Steel Flanges

Division 1 - Pressure Vessels
Appendix 3 - Mandatory Rules for Bolted Flange Connections

C-111/A21.15 - Flanged C.I. Pipe with Threaded Flanges
C-207 Steel Pipe Flanges

Spec 6A-96 - Specification for Wellhead and Christmas

The two most commonly used flange standards for process and utilities pipework are ASME B16.5 and BS 1560 (British Standards).

API 6A (American Petroleum Institute) specifies flanges for wellhead and Christmas tree equipment.

Less common flange standards which may be encountered are flanges for metric or DIN standards.

PIPING GUIDE