API 608: Metal Ball Valves-Flanged, Threaded, and Welding Ends

1 Scope

1.1 API 608 standard specifes the requirements for metal ball valves suitable for petroleum, petrochemical, and industrial applications— corresponding to the nominal pipe sizes in ASME B36.10M—that have:

Sizes Covered:

— fanged ends in sizes DN 15 through DN 600 (NPS 1 / 2 through NPS 24);

— butt-welding ends in sizes DN 15 through DN 600 (NPS 1 / 2 through NPS 24);

— socket-welding ends in sizes DN 8 through DN 50 (NPS 1 / 4 through NPS 2); and

— threaded ends in sizes DN 8 through DN 50 (NPS 1 / 4 through NPS 2)

1.2 This standard applies to metal ball valves with pressure classes as follows:

Pressure Ratings: 

— fanged ends in Classes 150, 300, and 600;

— butt-welding ends in Classes 150, 300, 600, and 800;

— socket-welding ends in Classes 150, 300, 600, and 800;

— threaded ends in Classes 150, 300, 600, and 800.

1.3 This standard establishes requirements for bore sizes described as:

Bore Type:

— full bore;

— single reduced bore;

— double reduced bore.

1.4 API 608 standard applies to foating (seat-supported) ball (Figure C.1) and trunnion ball valve designs (Figure C.2). These fgures are to be used only for the purpose of establishing standard nomenclature for valve components—other foating and trunnion designs also exist.

1.5 This standard establishes additional requirements for ball valves that are otherwise in full conformance to the requirements of ASME B16.34, Standard Class.

1.6 If product is supplied bearing the API Monogram and is manufactured at a facility licensed by API, the requirements of Annex A shall apply.

1.7 Trunnion ball valves equipped with double piston efect seats are outside of the scope of this standard.