API 601

Covers — (historical) double-jacketed corrugated and spiral-wound metallic gaskets for raised-face pipe flanges and flanged connections in refinery service. This standard has been withdrawn.

Does NOT cover / superseded by — current metallic gasket requirements are governed elsewhere:

• Current metallic gaskets (spiral-wound/RTJ/jacketed) → ASME B16.20 (the successor).
• Nonmetallic gaskets → ASME B16.21.
• Bolted-joint assembly → ASME PCC-1.

API 601 is withdrawn — specify ASME B16.20 for new metallic gaskets and update legacy callouts.

Because API 601 is withdrawn, its requirements are historical only:

• Legacy Content — it defined double-jacketed and spiral-wound metallic gaskets for raised-face refinery flanges.
• Current Basis — equivalent requirements now live in ASME B16.20 (dimensions, colour coding, marking).
• Action — update any specification or drawing citing API 601 to ASME B16.20.

API 601 was API's metallic-gasket specification for raised-face refinery flanges (double-jacketed and spiral-wound). It has been withdrawn (2013) and superseded by ASME B16.20, which now carries the dimensions, colour coding, and marking for metallic gaskets.

The entry is kept for historical traceability: legacy refinery drawings and specifications still reference "API 601," and recognizing it as an obsolete callout — to be replaced by B16.20 — prevents procurement confusion.

Engineering Note: Do not order new gaskets "to API 601." Reissue the specification to ASME B16.20 and confirm the spiral-wound/RTJ details match the current flange.