Stainless Steel Flanges

Product Description

Stainless Steel Pipe Flanges are forged or plate-machined connectors used in systems requiring superior corrosion resistance, chemical stability, high-temperature strength, and hygienic performance across chemical, pharmaceutical, oil and gas, food processing, and marine industries.

1. Common Material Grades & Specifications

Stainless steel flanges are primarily governed by ASTM A182 (forged flanges for high-temperature/pressure service) and ASTM A240 (plate flanges):

2. Structural Types & Attachment Methods

• Weld Neck (WN): Joined by a full-penetration butt-weld; distributes stresses evenly for high-pressure, high-temperature, or cyclic loads.

• Slip-On (SO): Double fillet-welded inside and out; easier field alignment at lower fabrication cost.

• Blind (BL): Solid forged disc used to blank off or terminate pipeline ends and vessel nozzles.

• Socket Weld (SW): Recessed socket holds small-bore piping ($\text{NPS } \le 2$) prior to fillet welding.

• Threaded (TH): Screwed connection using NPT or BSP threads; ideal where welding is prohibited.

• Lap Joint (LJ): Loose backing flange paired with a stainless steel stub end to reduce overall material expense.

3. Sealing Face Configurations

• Raised Face (RF): Features concentric serrations ($125\text{--}250\text{ AARH}$) to concentrate seating stress on spiral-wound, PTFE, or non-asbestos gaskets.

• Flat Face (FF): Fully flat surface; used when connecting to low-pressure flat-faced equipment or fragile cast valves.

• Ring Type Joint (RTJ): Features a precision annular metallic groove for solid oval or octagonal stainless/alloy ring gaskets under extreme pressure.

• Tongue & Groove (T&G) / Male & Female (M&F): Interlocking joint faces that prevent gasket lateral displacement under pressure.

4. Primary Dimensional Standards & Ratings

• ASME B16.5: Pipe Flanges and Flanged Fittings ($\text{NPS } 1/2 \text{ to } 24$, Class 150, 300, 400, 600, 900, 1500, 2500).

• ASME B16.47 Series A & B: Large Diameter Flanges ($\text{NPS } 26 \text{ to } 60$, Class 75 through Class 900).

• EN 1092-1: European Metric Series (DN 10 to DN 4000, PN 2.5 through PN 400).

• JIS B2220: Japanese Industrial Standard ($5\text{K}, 10\text{K}, 16\text{K}, 20\text{K}, 30\text{K}$).