ISO 15607, Specification and qualification of welding procedures for metallic materials—General rules

ISO TR 15608:2013, Welding—Guidelines for a Metallic Materials Grouping System

ISO 15609 (all parts), Specification and qualification of welding procedures for metallic materials—Welding procedure specification

ISO 15614-1, Specification and qualification of welding procedures for metallic materials—Welding procedure test—Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys

ISO 15614-7, Specification and qualification of welding procedures for metallic materials—Welding procedure test—Part 7: Overlay welding

ISO 80000-1:2009, Quantities and units—General principles MSS SP-44, Steel Pipeline Flanges

MSS SP-55, Quality Standard for Steel Castings for Valves, Flanges and Fittings and Other Piping Components—Visual Method for Evaluation of Surface Irregularities

NACE MR0103, Materials Resistant to Sulfide Stress Cracking in Corrosive Petroleum Refining Environments

NACE MR0175 (all parts), Petroleum and natural gas industries—Materials for use in H2S-containing environments in oil and gas production

3Valve Types and Configurations

3。1Valve Types

3。1。1Gate Valves

Typical configurations for gate valves with flanged and welding ends are shown, for illustration purposes only, in Figure B。1 and Figure B。2。

Gate valves shall have an obturator that moves in a plane perpendicular to the direction of flow。 The gate can be constructed of one piece for slab-gate valves or of two or more pieces for expanding-gate valves。

Gate valves shall be provided with a back seat or secondary stem sealing feature in addition to the primary stem seal。

3。1。2Lubricated and Nonlubricated Plug Valves

Typical configurations for plug valves with flanged and welding ends are shown, for illustration purposes only, in Figure B。3。

Plug valves shall have a cylindrical or conical obturator that rotates about an axis perpendicular to the direction of flow。

3。1。3Ball Valves

Typical configurations for ball valves with flanged or welding ends are shown, for illustration purposes only, in Figure B。4, Figure B。5, Figure B。6, and Figure B。14。

Ball valves shall have a spherical obturator that rotates on an axis perpendicular to the direction of flow。

3。1。4Check Valves

Typical configurations for check valves are shown, for illustration purposes only, in Figure B。7 to Figure B。13。 Check valves can also be of the wafer, axial flow, and lift type。

Check valves shall have an obturator that responds automatically to block fluid in one direction。

3。2Valve Configurations

3。2。1Full-opening Valves

Full-opening valves shall be unobstructed in the fully opened position and shall have an internal minimum cylindrical opening for categorizing bore size as specified in Table 1。 When pipe is used in the construction of the valves, the pipe shall meet the tolerances of the applicable pipe specification。 Obturator and seat dimensions shall meet Table 1。

NOTE There is no restriction on the upper limit of valve bore sizes。

When there is no minimum bore dimensions listed for a valve pressure class and size stated in Table 1, the size and bore shall be by agreement and the manufacture shall stamp the size and bore on the nameplate。

Welding-end valves can require a smaller bore at the welding end to mate with the pipe。

Valves with a noncircular opening through the obturator shall not be considered full opening。

Table 1—Minimum Bore for Full-opening Valves

NPS

DN