API 608 Metal Ball Valves—Flanged, Threaded and Welding Ends

API 608 specifies the requirements for metal ball valves suitable for petroleum, petrochemical and industrial applications that have:
— flanged ends in sizes NPS 1/2 through NPS 20 (DN 15 through DN500);
— butt-welding ends in sizes NPS 1/2 through NPS 20 (DN 15 through DN 500);
— socket-welding ends in sizes NPS 1/4 through NPS 2 (DN 8 through DN 50);
— threaded ends in sizes NPS 1/4 through NPS 2 (DN 8 through DN 50).
Corresponding to the nominal pipe sizes in ASME B36.10M.

API 608 applies to metal ball valves with pressure classes as follows:
— flanged ends in Classes 150, 300 and 600 (PN 16, 25, 40 and 100);
— butt-welding ends in Classes 150, 300 and 600 (PN 16, 25, 40 and 100);
— socket-welding ends in Classes 150, 300, 600 and 800 (PN 16, 25, 40 and 100);
— threaded ends in Classes 150, 300, 600 and 800 (PN 16, 25, 40 and 100).

API 608 establishes requirements for bore sizes described as:
— full bore;
— single reduced bore;
— double reduced bore.

API 608 applies to floating ball valve designs (Figure B.1) and trunnion ball valve designs (Figure B.2).
These figures are to be used only for the purpose of establishing standard nomenclature for valve components—
other floating and trunnion designs also exist.

API 608 establishes additional requirements for ball valves that are otherwise in full conformance to the
requirements of ASME B16.34, Standard Class.