API 608:2008 pdf download

API 608:2008 pdf download.Metal Ball Valves—Flanged,Threaded and Welding Ends.
3 Terms and Definitions
3.1
Class
An alphanumeric desgnation that is used for reference purposes relating to valve pressure/temperature capability, taking into account valve material mechanical properties and valve dimensional characteristics, It comprises the letters Class followed by a dimensionless whole number. The number following the letters Class do not represent a measurable value arid are not used for calculation purposes except where specified ii this Standard. The allowable pressure for a valve having a Class number depends on the valve material and its application temperature and is to be found in tables of pressure/temperature ratings. Class usage is applicable to steel valves beanng NPS nominal size designations.
3.2
An alpha numeric designation of size that is common for components used Wi a piping system, used for reference purposes, comprising the letters NPS followed by a dimensionless number indirectly related to the physical size of the bore or outside diameter of the end connection as appropriate. The dimensionless number may be used as a valve size identifier without the prefix NPS. The dimensionless size identification number does not represent a measurable value and is not used for calculation purposes. Prefix NPS usage is applicable to steel flanges bearing Class
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3.3
ON
An alpha numeric designation of size that is common for components used in a piping system, used for reference purposes, comprising the letters DN followed by a dimensionless number indirectly related to the physical size of the bore or outside diameter of the end connection as appropriate. The dimensionless number following DN does not represent a measurable value and is not used for calculation purposes except where specified in this international standard DN usage is applicable to steel valves bearing PN designations.
5.8.7 Lever type handles shall be parallel to the ball bore, so that lever always Indicates ball bore position. If the purchaser specifies round or oval direct-mounted handwheels. a permanent means of indicating ball bore position shall be included ii handwheel design.
5.8.8 An IndIcation of the position of ball bore of the valve shall be integral with the valve stem. This indication may be by permanent marking to the top of the stern, or by shape of exposed stem portion.
5.8.9 Levers. handwheels and other operating mechanisms shall be fitted so that they may be removed and replaced without affecting the integflty of the stem seal(s), body seal(s) or stern retention means.
5.8.10 Lever or manual gear operators shall be designed so that the lever or gear operator cannot be assembled to the valve other than in the correct configuration to indicate open and closed positions.
5.8.11 When specified in the purchase order, valves shall be furnished with a lockable device that accepts a purchaser-supplied padlock that allows the valve to be locked in both the fully open and fully closed positions The lockable device shall be designed such that a lock with a 5116-in. (8-mm) diameter shank, not more than 4.0 in. (102 mm) long can be inserted directly through hole(s) in lockable device and locked. Provision for lockable device is permitted, even when not speolfied on purchase order.
5.8.12 Position stops integral witl packing gland, gland flange or gland bolting shall not be used.
5.9 End Flange Face InterruptIons
5.9.1 Ring shaped radial gaps in the faces of end flanges of flanged ball valves, located in the sealing surface of a centered ASME B16 .20 spiral-wound gasket, shall not exceed 0.030 in. (0.75 mm); see dimension b on Figure 1. An example of this condition Is the radial gap that exists between the outer diameter of a body insert and the inner bore of the body end flange of a valve as shown in Figure B.1.
5.9.2 For baN valves designed with a body insert as shown in Figure B. 1, with a gasket seating face outer diameter located within the sealwig area of a centered ASME B16.20 spiral-wound gasket, the body Insert flange face shall not protrude beyond the valve body end flange face. The body insert flange face shall not be recessed below the body end flange face by more than 0.010 in, (0.25 mm). See dimension a on Figure 1.
5.10 Valve Shell Joints
5.10.1 Nut and bolt head bearing surfaces of shell parts assembled by bolting shall be perpendicular to the centerline of tapped or clearance holes for the fasteners within ± 1.0 degree.
5.10.2 Bolting used for assembly of shel joints shall be studs with nuts or cap screws. Nuts shall be semi-finished hexagons conforming to ASME B18.2.2. Bolts and studs shall be threaded in conformance to ASME 81.1 unless purchaser specifies metnc series bolting. Bolting 1 In. (25.4 mm) or smaler shall have coarse (UNC) threads; bolting larger than 1 in. (25.4 mm) shall be 8 thread sehes (8UN). Bolt and stud threads shall be Class 2A, and not threads shall be Class 28 per ASME B1.1.