flanges

Non-Standard Flanges are any flanges that do not conform to the dimensions, materials, pressure ratings, or design specifications outlined in established industry standards like ASME B16.5, ASME B16.47, EN 1092-1, or MSS SP-44. These flanges are custom-designed and manufactured to meet the unique requirements of a specific application that cannot be satisfied by an off-the-shelf, standard ASME B16.5 forged flanges. Key Reasons for Using Non-Standard Forged Flange: 1. Unique Dimensional Requirements:

1. • Odd Sizes: Connecting to equipment with a nozzle or opening that is not a standard NPS (Nominal Pipe Size).

   • Special Bolt Patterns: A bolt circle diameter (B.C.D.) or number of bolts that differs from the standard to match existing equipment.

   • Non-Standard Thickness or Hub Dimensions: Requires a thicker or thinner wall for unusual pressure loads or to fit a specific spatial constraint.

2. Special Material Requirements:

   • Exotic Alloys: Applications requiring a material not covered by standard flange specifications (e.g., Hastelloy, Inconel, Monel, Titanium, or Zirconium) often need to be custom-made.

   • Clad or Lined Flanges: A flange with a carbon steel body for strength but internally clad with stainless steel, nickel alloy, or even a polymer lining for corrosion resistance. The specific cladding process and thickness may be non-standard.

3. Unusual Pressure or Temperature Ratings:

   • Extreme Conditions: Applications that operate at pressures or temperatures far beyond (or between) the ratings of standard Class flanges require a custom-engineered design with a specific thickness and material grade.

4. Integration with Special Equipment:

   • Proprietary Equipment: Connecting to a heat exchanger, reactor, pump, or compressor that has proprietary flange connections not built to a common standard.

   • Vessel OEM Requirements: Many pressure vessels have manways and nozzles designed by the manufacturer that may not strictly adhere to a pipe flange standard.

5. Functional Design Modifications:

   • Extended Neck / Long Weld Neck (LWN) Flanges: A weld neck flange with an exceptionally long hub to act as a pipe reinforcement or to place the weld away from a high-stress area.

   • Reducing Flanges: While standard reducing flanges exist, a custom reduction (e.g., from a very large to a very small size) might be necessary.

   • Flanges with Special Nozzles or Connections: A flange might have additional smaller threaded or welded outlets, lugs for lifting, or connections for instrumentation.