How to choose flange material?

Choosing the right flange material is critical for pipeline safety,sealing performance,service life and operating cost.The selection should be based on working pressure,temperature,medium corrosion,installation environment and industry standards.Here are the core factors for reference:

1.According to working temperature and pressure

Low pressure&normal temperature:Common carbon steel(Q235,20#)is cost-effective and widely used in water supply,drainage and general industrial pipelines.

High temperature&high pressure:Use high-strength forged carbon steel or alloy steel to avoid deformation,cracking and leakage under extreme working conditions.

Low temperature environment:Low-temperature resistant carbon steel or stainless steel is required to prevent brittle fracture in cold conditions.

2.According to conveying medium&corrosion

Ordinary water,air,non-corrosive fluid:Carbon steel flanges fully meet daily use with low cost.

Acid,alkali,salt,chemical corrosive medium:Prefer stainless steel(304,316L).316L performs better in anti-rust and anti-acid corrosion,suitable for chemical,pharmaceutical and seawater environments.

Strong corrosive special medium:Duplex stainless steel or lined anti-corrosion flanges can be selected to extend service life.

3.According to production process&structural demand

Cast flange:Low cost,suitable for low-pressure and low-load conventional pipelines.

Forged flange:Denser texture,higher mechanical strength,better pressure resistance,preferred for high-pressure engineering and pressure vessel matching.

4.Environmental and cost factors

Outdoor humid,coastal salt fog areas:Stainless steel or anti-corrosion coated carbon steel is recommended to prevent rust.

Budget-limited conventional projects:Prioritize carbon steel with surface anti-rust treatment;long-term harsh working conditions should choose high-grade anti-corrosion materials to reduce later maintenance costs.

5.Compliance with industry standards

Make sure the selected flange material meets GB,ANSI,JIS and other international standards,and match the pipe material,gasket and bolt grade,to ensure the overall connection tightness and system stability.