AS 2129:2000 pdf – Flanges for pipes, valves and fittings

AS 2129:2000 pdf – Flanges for pipes, valves and fittings.
4.1 NIANUFACTURING METHODS Flanges may he produced from—
(a) one piece of material without welding except for repairs permitted by the material standard: or
(b) by ring rolling, or segments of plate or bar welded with a full penetration weld(s) made in accordance with a pressure vessel standard and with the purchaser’s agreement.
Where welding neck flanges are forged, the direction of the grain flow in the material in the neck shall be parallel to the longitudinal axis and, in the face, perpendicular to the longitudinal axis of the flange.
4.2 FLAN(;E DIMENSIONS
4.2.1 General The dimensions of flanges shall be as given in Section 6. For guidance on tolerances not specified in this Standard, refer to the AS!NZS 4331 series.
4.2.2 Tolerance on flange thickness The actual flange thickness shall be not less than:
(a) For grey iron. malleable iron. ductile iron 0.957’ + 0.75 mm.
(b) For all other material 7’ — 0.5 mm.
NOTE: To achieve the surface requirements of Clause 4.3.2. it may be necessary lo machine the contact surface after the flange has been welded or brazed to the pipe. valve or fitting. Such cases may necessitate a machining allowance in the original thickness.
4.2.3 I)imensions of 0-ring grooves The dimensions for the 0-ring groove, shall be as specified in the flange Tables of Section 6.
4.2.4 height of raised face The height of a raised face shall be 1.6 mm.
4.3 FLANGE FACES
4.3.1 General Flanges shall be manufactured with a flat face, raised face, or flat face with an 0-ring groove, as limited by the flange table, the flange material and the type of flange as shown in Table 4.1.
4.3.2 Contact surface for flange faces
4.3.2.1 General The contact surface for flange faces shall he machined or otherwise finished so that the flatness and squareness to the axis and the surface finish are appropriate to the type of gasket.
4.3.2.2 Surface finish Where turning (see Note) is used to generate either a spiral groove or concentric grooves, the tool shall be round-nosed and have a radius of
approximately 1.5 mm.
The approximate dimensions of the groove shall be as follows:
(a) Pitch 0.8 mm.
(b) Depth 0.05 mm.
The contact surface produced by turning shall be not rougher than R 12.5 pm. nor smoother than R 3.2 pm. in accordance with AS 2536.
NOTE: The term turning’ includes any method of machine operation which produces either spiral or concentric grooves.
The contact surface produced by means other than turning shall be not rougher than Ra 6.3 pm, nor smoother than Ra 3.2 pm. in accordance with AS 2536.