BS 1873: Steel globe and globe stop and check valves (flanged and butt-welding ends) for the petroleum, petrochemical and allied industries

BS 1873 Standard specifies requirements for cast or forged carbon and alloy steel outside screw and yoke globe valve and globe stop valve and check valves, straight pattern, angle pattern and (oblique) Y pattern, with flanged or butt-welding ends in nominal sizes within the range of 15 mm to 400 mm (; in to 16 in) and Classes 150 to 2500.

BS 1873 standard can also be used as a general guide where valves of material composition outside the scope of section three of this standard are required as, for example, for use in highly corrosive services or environments or for low temperatures (see clause 37).

BS 1873 standard can be adapted to apply to valves with needle type seats in 15 mm (; in) an 20 mm (< in) nominal sizes which will meet all requirements of this standard, except that the valve seat bore is reduced and the needlepoint may be either integral with or loose on the stem.

8 Body

8.1 For the body the design criteria specified in 8.2 to 8.10 shall be observed.

8.2 The body shall be designed to minimize pressure loss as well as corrosive and erosive effects. The

body end ports shall be circular. The area of the flow passage shall everywhere be as near equal to the area of the body end ports as practicable.

8.3 The body wall thickness shall comply with the requirements for shell thickness in Appendix A. Drilling of, or pinning to, the wallis not permissible, e.g. for nameplate fixing where this would reduce the effective thickness below the minimum permitted value.

8.4 Face-to-face and centre-to-face dimensions for raised face flanged end valves and end-to-end and centre-to-end dimensions for butt-welding end and ring joint flanged end valves shall conform to the dimensions specified in BS 2080. Stop and check valves shall have the same dimensions as globe valves of similar pattern.

8.5 End flanges shall be cast or forged integral with the body except that flanges may be attached by welding if so specified in the order. The welds of end flanges attached by butt-welding shall comply with the requirements of BS 3351 and shall have any necessary heat treatment as required by BS 3351 to ensure that they are suitable for service temperatures down to – 30 。C. Flange attachment by other welding processes shall be the subject of agreement between the manufacturer and the purchaser.

8.6 End flanges shall comply with the requirements of BS 1560-2. End flange facings shall be one of the types shown in Figures 1 and 2 of BS 2080. The purchasershall specify the type of facing required. Valves generally in accordance with this standard but suitable for use in piping systems with BS 4504 flanges shall comply with the requirements of Appendix B.