API 603: Corrosion-resistant, Bolted Bonnet Gate Valves—Flanged and Butt-welding Ends

1 Scope

1.1 API 603 standard specifies the requirements for corrosion-resistant bolted bonnet gate valves meeting the requirements of Standard Class, ASME B16.34 and having full port openings for use in process piping applications.

API 603 standard sets forth the requirements for the following gate valve features:

— bolted bonnet;

— outside screw and yoke;

— rising stems;

— non-rising handwheels;

— single or double gate;

— wedge or parallel sealing;

— metallic seating surfaces;

— flanged or butt-welding ends.

Sizes Covered:

Covering valves of the nominal pipe size DN:

— 15; 20; 25; 32; 40; 50; 65; 80; 100; 150; 200; 250; 300; 350; 400; 450; 500; 600.

Corresponding to the nominal pipe size NPS:

—1 / 2 ; 3 / 4 ; 1; 1 1 / 4 ; 1 1 / 2 ; 2; 2 1 / 2 ; 3; 4; 6; 8; 10; 12; 14; 16; 18; 20; 24.

Pressure Ratings Covered:

Applies to pressure class designations:

— 150; 300; 600.

1.2 Annex C illustrates a bolted bonnet gate valve for the purpose of establishing standard nomenclature for valve parts.

1.3 The dimensions in metric (SI) units are standard; customary units are shown for reference.

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

5.1 Body Wall Thickness

5.1.1 A valve body schematic is shown in Figure 1. The minimum body wall thickness, t m , at the time of manufacture shall be as given in Table 1, except as indicated in 5.1.2 for butt-welding valve ends. Additional metal thickness needed for assembly stresses, stress concentrations, and shapes other than circular shall be determined by individual manufacturers.

Table 1—Minimum Thickness of Shell/Bonnet Wall, t m and Minimum Diameter of Stem, ds

Size		Class 150		Class 300		Class 600
DN	Inch	Shell/Bonnet Wall Thickness	Stem Diameter	Shell/Bonnet Wall Thickness	Stem Diameter	Shell/Bonnet Wall Thickness	Stem Diameter
15	1/2	3.2	10.7	3.3	12.3	3.6	12.3
20	3/4	3.6	10.7	3.8	12.3	4.2	12.3
25	1	4.0	12.3	4.3	15.5	4.8	15.5
32	1-1/4	4.4	12.3	4.8	15.5	5.1	15.5
40	1-1/2	4.8	13.9	5.2	18.7	5.5	18.7
50	2	5.5	15.5	6.1	18.7	6.2	18.7
65	2-1/2	5.8	15.5	6.5	18.7	7.1	21.8
80	3	6.0	18.7	6.9	21.8	7.9	25.0
100	4	6.4	21.8	7.8	25.0	9.6	28.2
150	6	7.2	25.0	9.4	31.3	13.1	37.6
200	8	8.0	28.2	11.1	34.4	16.3	40.7
250	10	8.8	31.3	12.8	37.6	19.5	46.9
300	12	9.7	34.4	14.5	40.7	22.9	50.1
350	14	10.2	40.7	15.5	43.8	24.9	56.4
400	16	11.0	43.8	17.2	46.9	28.1	59.5
450	18	11.8	46.9	18.6	50.1	31.1	62.7
500	20	12.7	50.1	20.3	53.3	34.1	69.1
600	24	14.3	56.4	23.7	62.7	40.5	75.4

5.1.2 The weld end preparation in butt-welding end valves (see 5.3.2) shall not reduce the body wall thickness to less
than the values specified in 5.1.1 within a region closer than t m to the outside surface of the body neck, measured along
the run direction. The transition to the weld preparation shall be gradual, and the section shall be essentially circular
through the entire length of the transition. Sharp discontinuities or abrupt changes in section in areas that infringe into
the transition shall be avoided. In no case shall the thickness be less than 0.77 t m at a distance of 2 t m from the weld end.

5.2 Bonnet Wall Thickness

The minimum bonnet wall thickness at the time of manufacture, except for the part of the neck extension that contains
the packing, shall be t m as given in Table 1. For the neck extension, the local minimum wall thickness shall be based on
the local diameter, e.g., the inside diameter of the stem bore or packing box bore, and shall be in accordance with valve
body neck rules of ASME B16.34.

NOTE 1- See 5.8.1 and 5.8.3.

NOTE 2- Wall thickness calculated from equation of ASME B16.34, with minimum flow diameter (d) per ASME B16.34 for applicable