1. SCOPE

This standard specifies the classification, marking, requirements, test methods, inspection rules, marking, packaging, and storage of cast steel suction sea valves (hereinafter referred to as "sea valves") where flange connection dimensions and sealing surfaces comply with GB/T 569 and GB/T 2501.
This standard is applicable to the design, manufacture, and acceptance of sea valves in fresh water and seawater piping systems of ships.

2. NORMATIVE REFERENCES

The provisions of the following documents become provisions of this standard through reference in this standard. For dated references, subsequent amendments (excluding errata) or revisions do not apply to this standard; however, parties agreeing to this standard are encouraged to investigate whether the latest editions of the following documents apply. For undated references, the latest edition applies to this standard.
GB/T 41-2000 Hexagon nuts, grade C (eqv ISO 4034:1999)
GB/T 569 Ship flanges - Connection dimensions and sealing faces
GB/T 600 General technical requirements for ship piping valves (GB/T 600-1991, neq ISO 5208:1982)
GB/T 897-1988 Double-head studs bm=1d
GB/T 1176-1987 Casting copper alloy technical conditions (neq ISO 1338:1977)
GB/T 1184-1996 Geometrical tolerances - Unindicated tolerance values (eqv ISO 2768-2:1989)
GB/T 1804-2000 General tolerances - Tolerances for linear and angular dimensions without individual tolerance indications (eqv ISO 2768-1:1989)
GB/T 1958 Geometrical product specifications (GPS) - Geometrical tolerance verification
GB/T 2501 Ship flanges - Connection dimensions and sealing faces (four-position) (GB/T 2501-1989, neq ISO 2084:1974)
GB/T 3032 Marking of ship piping accessories
GB/T 4423-2007 Copper and copper alloy drawn rods
GB/T 11698 Ship flanges - Structural length for connecting metal valves (GB/T 11698-1989, neq ISO 5752:1982)
GB/T 12229-2005 General purpose valves - Technical specifications for carbon steel castings
GB/T 3927 Wall thickness of ship casting valves

3. CLASSIFICATION AND MARKING

3.1 TYPE

Sea valve types are specified as follows:
Type B: Sea valves with flange connection dimensions and sealing surfaces in accordance with GB/T 569.
Type BS: Sea valves with flange connection dimensions and sealing surfaces in accordance with GB/T 2501.

3.2 BASIC PARAMETERS

The basic parameters of sea valves are shown in Table 1.

TABLE 1 - BASIC PARAMETERS OF SEA VALVES

3.3 STRUCTURE AND BASIC DIMENSIONS

The structure and basic dimensions of the sea valves are shown in Figure 1 and Tables 2 and 3.

TABLE 2 - BASIC DIMENSIONS OF TYPE B SEA VALVES (Unit: mm)

TABLE 3 - BASIC DIMENSIONS OF TYPE BS SEA VALVES (Unit: mm)

3.4 PRODUCT MARKING

[Diagram showing marking structure: Type code | 10 times the nominal pressure value, unit MPa | Nominal diameter value (pad with "0" if less than three digits), unit mm]

3.5 MARKING EXAMPLE

For a cast steel suction sea valve with nominal pressure 0.4 MPa, nominal diameter 80 mm, and flange connection dimensions and sealing surfaces in accordance with GB/T 569, the marking is:
Sea Valve GB/T 2029-2008 B4080
For a cast steel suction sea valve with nominal pressure 0.4 MPa, nominal diameter 100 mm, and flange connection dimensions and sealing surfaces in accordance with GB/T 2501, the marking is:
Sea Valve GB/T 2029-2008 BS4100

4. REQUIREMENTS

4.1 MATERIALS

4.1.1 The main part materials of the sea valves are specified in Table 4.

TABLE 4 - MAIN PART MATERIALS FOR SEA VALVES