Non-standard Large Diameter Welding Flange

Why are traditional flanges not enough to solve your difficulties?

1. Pressure limitation: Non-standard Large Diameter Welding Flanges can only withstand 16Bar at 150°C, while deep-sea oil and gas projects need to withstand ultra-high pressures of 300Bar+.

2. Risk of seal failure: Dangerous fluid transportation requires absolute sealing of <1ppm while the leakage rate of standard flange gaskets is >100ppm

3. Material bottleneck: Non-standard large-diameter welded flanges require ultra-low loss of less than 0.1mm/year in high-corrosion conditions, while ordinary flanges have a corrosion rate of >0.5mm/year in acidic environments

4. Size constraints: Pipeline projects or large reaction vessels usually require giant connections with a minimum of DN1500 to DN3000 or more. However, the maximum diameter of standard flanges usually stops at DN600, which cannot meet the needs.

Our non-standard customized solutions:

High-pressure certification: Customized according to customer requirements, the actual pressure bearing capacity of non-standard large-diameter welded flanges can reach PN420 or above, and there is no leakage or deformation after the 32MPa water pressure test.

Material strengthening: Customized alloy formula is used, which is nearly 80% higher than standard carbon steel, and the yield strength is ≥450MPa.

Precise thickening of key parts: For example, on the DN2000 flange, the maximum stress in the stress concentration area is reduced by 40% after optimization, and the thickness is increased by 25%. Large diameter precision can reach millimeter-level accuracy

Large diameter capability: Mature manufacturing of DN4000 (160”) grade flanges, with a single piece weight of over 20 tons. Adopting segmented temperature control heat treatment to ensure that the overall hardness deviation is ≤HB15.

Thick wall welding groove: For thick wall pipes, deep J-shaped or U-shaped grooves are designed to significantly improve the service life of welds.

Special alloy application: Provide options such as titanium alloy, duplex steel 2205, Hastelloy C276, etc., with an annual corrosion rate of <0.1mm in boiling acidic solution.

Seal reliability engineering:

Using mirror turning with Ra ≤3.2μm, combined with customized types such as tongue and groove surface, annular groove, concave and convex surface, to ensure zero leakage of metal spiral wound gaskets or O-rings.

Cooperative development of PTFE/graphite/metal composite gaskets, the measured sealing pressure is 1.5 times the rated pressure of the flange.

Reduce downtime losses: Ultra-high reliability design, expected to reduce 90%

Eliminate the risk of leakage: The sealing system has passed API 6A / ISO 5208 zero leakage certification to ensure the absolute safety of high-risk media.

Successful cases:

Deep-sea oil and gas platform: Class 1500 (25MPa), DN1800, A694 F70 non-standard large-diameter welding flanges have been successfully applied to 3000-meter deep-sea high-pressure pipelines and have been operating without trouble for more than 5 years.

Sour gas transportation: UNS S31803 duplex steel flanges, serving in H2S partial pressure >0.3psi environment, 3 years of detection without stress corrosion cracking.

Giant chemical reactor: Customized Inconel 625 cladding flanges for DN3200 high-temperature (550°C) equipment, with thermal deformation <0.5mm to ensure continuous production.

Submit your operating parameters (pressure, temperature, medium, size, standard) and get a preliminary technical solution and feasibility assessment within 24 hours. Customized flange solutions for your unique challenges