Non-standard flanges are flange products that do not conform to national or industry standards (such as GB, ASME, DIN, etc.). Their design, dimensions, materials, and processes must be customized according to specific working conditions or customer needs. The following analyzes its product characteristics from multiple dimensions:

Customized design to adapt to special needs

Flexible size adjustment

According to special requirements such as pipe diameter, pressure level, and installation space, non-standard outer diameter, inner diameter, thickness, and bolt hole spacing can be customized. For example: Non-standard pipe diameter pipes (such as DN650, DN800, etc., non-national standard sizes) require non-standard flanges; special equipment interface irregular sizes (such as oval, rectangular flanges) also need to be designed separately.

Case: The reactor interface of a certain chemical enterprise is a non-standard taper, and the inner hole taper of the customized flange needs to be completely matched with the equipment to ensure sealing.

Targeted structural optimization

For extreme working conditions such as high pressure, high temperature, and strong corrosion, the flange neck thickness can be strengthened, stiffeners can be added, or the sealing surface form can be optimized (such as non-standard tenon groove surface, lens gasket sealing surface). For example: Non-standard flanges for high-pressure pipelines (design pressure > 10MPa) may use thicker necks and higher-strength bolt hole layouts.

Speciality of materials and processes

Application of unconventional materials

Non-standard metal materials (such as Hastelloy, titanium alloy, duplex stainless steel, etc.) or non-metal materials (such as reinforced polytetrafluoroethylene, fiberglass) can be used to meet the corrosion resistance requirements of special media (such as strong acids, strong alkalis, radioactive substances).

Case: A certain pharmaceutical factory needs to transport sterile corrosive liquid. The non-standard flange uses 316L stainless steel + electropolishing process, and the surface roughness is below 0.8μm, which meets the GMP standard.

Special manufacturing process

Some non-standard flanges require non-standard processes such as forging, cast steel, and rolling. For example: Large-diameter non-standard flanges (diameter > 2000mm) are often made by rolling steel plate welding, and then overall heat treatment is used to eliminate stress; irregular flanges (such as structures with convex or concave grooves) need to be customized by CNC machining centers.

Performance advantages: Adapting to complex working conditions

High sealing and reliability

For scenarios with high leakage risks (such as highly toxic media, vacuum systems), non-standard sealing structures can be designed. For example: Using metal wound gaskets + double sealing surface design, or adding leakage prevention grooves to the flange edge, combined with a nitrogen purge system, to ensure zero leakage.

Ability to resist special loads

Can withstand non-uniform loads (such as vibration, alternating stress), for example: Non-standard flanges used in nuclear power plants need to be subjected to seismic calculations, and the neck is designed with a gradual thickness to reduce stress concentration; flanges used on offshore platforms need to consider typhoon vibration and seawater corrosion, and the material needs to be added with anti-salt spray coating.

Application areas

Wind power industry	Shipbuilding	Mechanical manufacturing
Nuclear power industry	Oilfield industry	Chemical industry