Flange

Our nickel alloy and stainless steel flanges are hot forged to strict ASME and ASTM standards, ideal for high-pressure and corrosive industrial piping systems. Available in Inconel, Monel, Hastelloy and stainless steel grades, they feature high strength, excellent sealing performance and long service life. We supply weld neck, slip-on, blind, socket weld and other types with complete pressure ratings. Precision machining ensures tight tolerance and reliable connection. Widely used in petrochemical, oil & gas, water treatment and power generation. Custom sizes and material solutions are available for harsh working environments.

Material Standard

• Specification for Forged Nickel Alloy Steel Flanges
• Covers chemical, mechanical properties, testing, marking

Dimension Standards

• ASME B16.5: NPS 1/2" ~ 24" (most common for industrial piping)
• ASME B16.47: NPS 26" ~ 60" (large diameter flanges, Series A & B)
• MSS SP-44: Supplementary for high-pressure & special designs

Pressure Ratings (Class)

• Standard: 150#, 300#, 600#, 900#, 1500#, 2500#
• ASME B16.47: 75#, 150#, 300#, 400#, 600#, 900#

Common Nickel Alloy Grades (UNS)

• Nickel 200/201 (N02200/N02201)
• Monel 400 (N04400)
• Inconel 600, 625, 718 (N06600, N06625, N07718)
• Incoloy 800/800H/825 (N08800, N08825)
• Hastelloy C276, C22 (N10276, N06022)
• Alloy 20 (N08020)

Flange Face Types

• RF (Raised Face): Most common, standard gasket
• FF (Flat Face): Full-face gasket
• RTJ (Ring Type Joint): High-pressure (Class 600+)
• Male/Female (M/F), Tongue/Groove (T/G): Special sealing

Common Flange Types & Dimensions

1. Weld Neck Flange (WN) – Long Weld Neck (LWN)

• Design: Tapered hub, butt-weld to pipe; high strength & fatigue resistance
• Standard: ASME B16.5, B16.47
• Size: NPS 1/2" ~ 60"
• Best for: High pressure, temperature, cyclic loads
  

2. Slip-On Flange (SO)

• Design: Slips over pipe, fillet-welded outside & inside
• Size: NPS 1/2" ~ 24"
• **Lower cost, easier alignment; lower pressure rating
  

3. Socket Weld Flange (SW)

• Design: Socket recess, pipe inserted, fillet-welded
• Size: NPS 1/2" ~ 4" (up to 24" special)
• **For small bore, high-pressure piping
  

4. Blind Flange (BL)

• Design: Solid plate, to blank pipe ends
• Size: NPS 1/2" ~ 60"
• **Pressure testing, isolation
  

5. Threaded Flange (TH)

• Design: Internal pipe thread, no welding
• Size: NPS 1/2" ~ 4"
• **Low-pressure, non-weld systems
  

6. Lap Joint Flange (LJ)

• Design: Loose flange with stub end; rotational ease
• Size: NPS 1/2" ~ 24"
• **Corrosive service, frequent disassembly
  

7. Spectacle Blind / Spade & Ring

• Design: Combo blind/through plate for line blinding
• Size: NPS 1/2" ~ 60"
• **Maintenance isolation
  

Standard NPS Sizes (ASME B16.5)

Key Dimensions (WNRF Class 150/300)

• NPS 2" (DN50):
  • OD: 152 mm / Bolt Circle: 114 mm / 8 bolts
  • Hub Dia: 73 mm / Thickness: 17.5 mm (150#)
• NPS 4" (DN100):
  • OD: 216 mm / Bolt Circle: 178 mm / 8 bolts
  • Hub Dia: 114 mm / Thickness: 22.2 mm (150#)

Typical Applications

• Chemical & petrochemical processing
• Oil & gas transmission/refining
• Power generation (heat exchangers)
• Marine & offshore (seawater systems)
• Pharmaceutical & food processing
• High-temperature/pollution control

Selection Notes

• Weld Neck (WN): Preferred for nickel alloy (best fatigue/corrosion)
• Class 150/300: Most common; 600+ for high pressure
• RF Face: Standard for most nickel alloy piping
• RTJ: Used for Class 600+ & sour gas