Complete FAQ answer for industrial pipeline website

1.Raw Material&Chemical Composition

Carbon steel flange(A105,A350 LF2)

Main component:iron+carbon,little chromium&nickel.Low alloy content.

Stainless steel flange(304/316/316L)

Contains over 10.5%chromium,plus nickel.Chromium forms a passive oxide film on surface for rust resistance.

2.Corrosion Resistance(Core Difference)

Carbon steel:Easy to oxidize and rust when contacting water,moisture,salt fog or weak acid.Must do anti-corrosion coating(paint,galvanizing,3PE).Cannot work with seawater,chemical acid&alkali media.

Stainless steel:Excellent anti-rust and anti-corrosion performance.

304:Fit fresh water,indoor gas,general food pipelines.

316L:Resist chloride,seawater,acid liquid,coastal&chemical plant environments.

No extra anti-rust coating needed.

3.Working Temperature Performance

Carbon steel A105:Operating range-29℃~425℃;WP alloy carbon steel suits high-temperature steam pipelines.Good mechanical strength at high temperature.

Stainless steel:Stable under low temperature and medium-high temperature;321 stainless steel flange is specially for high-temperature thermal oil and boiler pipes.

4.Mechanical Property&Pressure Bearing

Carbon steel:Higher tensile strength and hardness at equal wall thickness.More cost-effective for heavy-load high-pressure oil&gas pipelines.Less ductility.

Stainless steel:Better toughness and ductility,easy machining and polishing.Slightly lower compressive strength than carbon steel of the same thickness;thicken the plate if ultra-high pressure required.

5.Surface Treatment

Carbon steel flange:Shot blasting+anti-rust primer/galvanization/black paint to prevent rust before delivery.

Stainless steel flange:Pickling passivation as standard;sanitary flanges adopt mirror polishing for food,pharmacy pipelines.

6.Application Scenarios

Carbon Steel Flange

Oil,natural gas,steam,heating power pipelines

Buried outdoor pipelines with anti-corrosion treatment

General industrial water supply without corrosive medium

Large-diameter high-pressure engineering projects with strict cost control

Stainless Steel Flange

Food,beverage,dairy,pharmaceutical sanitary pipeline

Seawater desalination,coastal chemical industry

Wastewater,acid-base corrosive medium transmission

Indoor clean pipelines with high hygiene requirements

7.Price&Cost

Carbon steel flange:Much cheaper raw material,low production cost,the first choice for large-volume ordinary engineering.

Stainless steel flange:Chromium and nickel raise raw material cost,2–5 times higher price than carbon steel flange of same specification.

8.Service Life

Carbon steel:Short service life without regular anti-corrosion maintenance,prone to wall thinning and leakage from rust.

Stainless steel:Long service life with minimal maintenance,no frequent re-coating required.