• TOBO STEEL GROUP CHINA
    Brazil---Aimee
    In the latest vendor rating, TOBO won the excellent rating, it is good, will continue to cooperate.
  • TOBO STEEL GROUP CHINA
    Thailand ---Dave Mulroy
    ASTM A213 T9 Alloy steel pipe ,Stable quality , good price, excellent serive, TOBO GROUP is our trustworthy partner .
  • TOBO STEEL GROUP CHINA
    USA ---Alfaro
    ASTM A182 F55 Super Duplex Flange ,Good quality , we like that ! And delivery time in time also ,very professional.
Contact Person : Joy Wang
Phone Number : 0086-21-31261985
WhatsApp : +8613524668060

Corrosion Resistant Forged Steel Flanges for Petrochemical Acid Service

Place of Origin China
Brand Name TOBO
Certification ISO9001:2015; SGS/BV/ABS/LR/TUV/DNV/API/PED available
Model Number A182 F316L / 904L / Duplex
Minimum Order Quantity 300 Kilogram/Kilograms
Price US $ 20 - 200 / Kilogram
Packaging Details Plywood cases or customized
Delivery Time 7-30 days
Payment Terms L/C,T/T,Western Union
Supply Ability 50 Metric Ton/Metric Tons per Month
Product Details
Product Name Petrochemical Corrosion Resistant Forged Steel Flange Application Petrochemical Acid Service And Chemical Plant Piping
Material Grade A182 F316L / F904L / Duplex 2205 Flange Type Weld Neck / Slip-On / Blind / Socket Weld
Seal Face Raised Face (RF) / Ring Type Joint (RTJ) Surface Treatment Pickled And Passivated Surface
Design Standard ASME B16.5 / EN 1092-1 Testing PMI Verification + Hydrostatic Test
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Corrosion Resistant Forged Steel Flanges

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Petrochemical Acid Resistant Flanges

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Chemical Plant Forged Pipe Flanges

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Product Description
Corrosion Resistant Forged Steel Flanges for Petrochemical Acid Service
Product Overview
Corrosion resistant forged steel flanges for petrochemical acid service are manufactured from stainless and high alloy grades that maintain integrity in chemical plant environments where ordinary carbon steel fails within months. Sulfuric acid, hydrochloric acid, chlorides, and hot process streams attack standard materials through pitting, crevice corrosion, and stress corrosion cracking, making material selection the first line of defense.
Our corrosion resistant forged steel flanges are available in 316L, 904L, and duplex stainless steel, with each grade specifically matched to the aggressiveness of the media. For petrochemical acid service, we pay special attention to the flange surface condition. After machining, every flange undergoes pickling and passivation to restore the protective chromium oxide layer. PMI verification is performed on each heat to ensure the certified grade matches the installed material.
All flanges are 100% hydrostatically tested and can be supplied with RTJ faces and metal gaskets for demanding process connections.
Specifications
Materials A182 F316L, F904L, Duplex 2205 (S31803), Super Duplex 2507
Application Media Sulfuric acid, chlorides, caustic and aggressive chemical process streams
Pressure Rating Class 150 to Class 2500
Size Range 1/2" to 24" (DN15 to DN600)
Seal Face RF / FF / RTJ
Surface Condition Pickled and passivated
Testing PMI + hydrostatic test, optional intergranular corrosion test
Documentation EN 10204 3.1 certificate with heat numbers
Key Advantages
  • Grade selection by media: 316L for general chemical service, 904L for sulfuric acid, duplex for chloride stress corrosion cracking resistance
  • Pickled and passivated surface restores corrosion resistance after machining
  • PMI verified on every heat to prevent material mix-up in critical acid lines
  • Optional intergranular corrosion testing per ASTM A262 for sensitization control
  • Full traceability from ingot to finished flange with EN 10204 3.1 certificates
  • Wide pressure range supports both atmospheric storage piping and high pressure process units
Quality Assurance & Documentation
Corrosion resistant forged steel flanges for petrochemical acid service are manufactured with full material traceability from the original ingot to the finished flange. Each heat undergoes PMI verification, solution annealing or heat treatment is documented, and finished flanges are inspected for dimensions and surface condition before packing.
Our documentation package includes EN 10204 3.1 certificates, PMI reports, and test certificates. We regularly host third-party inspectors who verify corrosion resistant forged steel flanges for petrochemical acid service before shipment.
Frequently Asked Questions
Which material do you recommend for sulfuric acid service?
For dilute and medium concentration sulfuric acid at elevated temperature, 904L is a proven choice, while 316L suits milder conditions. Our engineers will confirm the appropriate grade once you share the acid concentration and operating temperature.
Why is passivation important for corrosion resistant forged steel flanges?
Machining removes the protective oxide layer and can leave iron contamination on the surface. Pickling and passivation remove these contaminants and rebuild the chromium oxide film, which is essential for the long service life of corrosion resistant forged steel flanges in petrochemical acid service.
Do you perform PMI testing?
Yes. Positive Material Identification is performed on every heat with an X-ray fluorescence analyzer, and the PMI report is included with the material certificate.
Can you supply duplex flanges for chloride service?
Yes. Duplex 2205 and super duplex 2507 forged steel flanges are available for seawater, brine, and chloride service, with high resistance to pitting and stress corrosion cracking.