Stainless Steel Forged Flanges

Weld Forged Flanges

A flange is a ring of steel (forged, cut from plate, or rolled) designed to connect sections of pipe, or to join pipe to a pressure vessel, valve, pump or other integral flanged assembly. Flanges are joined to each other by bolting, and are joined to the piping system by welding or threading (or loose when stub ends are used). The basic types of flanges are:

• Slipon
• Blind
• Weld neck
• Threaded
• Socket weld
• Lap joint
• Orifice

Standards

Forged stainless steel flanges are designed to the following common pressure ratings: Classes 150, 300, 600, 900, 1500 and 2500. Standard sealing face is Raised Face (RF).

Manufacturing specification: ASTM A182M and ASME B16.5. (Flanges over NPS24/DN 600 to ASME B16.47, API 60S or BS 3293) Plate stainless steel flanges are forged or cut and machined from plate – Table ‘D’, Table ‘E’, etc.

Manufacturing specification: AS2129 Waterworks flanges to AS4087 and PN16 flanges to EN 1092-1 are also available subject to enquiry.

Types and Applications of Flanges

Slip-on flanges – the flange is slipped over the pipe and then welded both inside and outside to provide sufficient strength and prevent leakage. Slip-on flanges are also used as loose back-up flanges when Type B stub ends are used.

Blind flanges – this is a flange without a centre bore, used to shut off a piping system or vessel opening.

Weld neck flanges – designed to be joined to a piping system by butt welding. They are relatively expensive due to the weld neck, but are preferred for high-stress applications.

Lap joint flanges – this is again similar to a slip-on flange, but has a radius at the intersection of the centre bore and the flange face to accommodate a Type A lap joint stub end.