Chemical Stainless Steel Flange
Built for extreme chemical environments. We deliver corrosion-resistant, high-strength stainless steel flanges. Customized for your toughest applications.
Our STRENGTHS
At Longan Flange, we understand the extreme demands of the chemical and petrochemical industries. Piping systems here face high pressure, high temperature, and highly corrosive media — often all at once.
We help you solve challenges like:
- Aggressive corrosion from chlorides, acids, alkalis, and urea
- Demanding sealing requirements under high pressure
- Frequent disassembly and inspection needs without damaging flanges
- Equipment compatibility issues with valves, pumps, and heat exchangers
- Premature failures due to improper material selection
EXPLORE OUR sTAINLESS STEEL FLANGES FOR CHEMICAL
We offer a full range of stainless steel flanges specifically designed for chemical applications.
Whether you’re working with acid gas, urea, EDC-VCM, or high-temperature steam, we provide the right connection for your system.
We manufacture Stainless Steel flanges according to multiple international and industry standards:
- GB/T 9119-2010
- HG/T 20592-2009 / HG/T 20615-2009
- ASME / ANSI
- DIN / BS / JIS
EXPLORE OUR sTANDARD CHEMICAL FLANGES
Sourced raw materials from Tsingshan Group, our material selection is tailored to your process conditions, ensuring maximum performance in corrosive and high-pressure environments.
- 304: F304, S30408, S30408II
- 304/304L: : F304, S30408, S30408II, S30403, 30403II
- 316L: 31603, 31603II, 31603III
- TP310S (06Cr25Ni20) — excellent high-temperature resistance
- TP321 (06Cr18Ni11 / T321-32168) — anti-intergranular corrosion
- 2205 (F51 / S22053III) — chloride resistance + high strength
- 2507 (F53) — exceptional corrosion resistance & strength for critical service
We also offer customized chemical flanges to meet your unique and demanding operating conditions.
CONTACT OUR SPECIALIST now and let us know your requirements—we will get back to you within 24 hours.























PRODUCT CATALOG
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Leak Prevention as core
We understand that even the smallest leak in a chemical plant can lead to environmental hazards, production shutdowns, or safety incidents. That’s why our flanges are:
- Precisely machined for optimal gasket compression and sealing
- Subjected to rigorous pressure and leakage tests before shipment
- International Standard Compliance
- Available with surface finishes that enhance sealing performance
Corrosion Resistance You Can Count On
Chemical processes often involve aggressive media — acids, alkalis, chlorides, and high-temperature steam.
All materials are traceable and tested to international standards. Custom material selection is also available based on your process conditions.
We carefully select materials that resist corrosion at the molecular level:
- 316L and 321 for general chemical resistance
- Duplex 2205 and Super Duplex 2507 for chloride-heavy and acidic environments
- 310S for oxidation resistance at high temperatures
Built for Pressure Proven Under Stress
Our flanges are engineered to perform under high operating pressures, even in dynamic systems with temperature fluctuations or vibration. We achieve this by:
- Using high-strength stainless and duplex steels
- Applying strict dimensional tolerances to ensure tight, secure fits
- Offering reinforced types such as weld neck flanges for high-pressure zones
Longer Service Life Less Downtime
We design our flanges not just to perform, but to last. With superior resistance to corrosion, cracking, and fatigue, Longan flanges:
- Have extended operational lifespans, even in continuous-use environments
- Reduce the frequency of replacements and shutdowns
- Lower your total cost of ownership (TCO) over time
Where Our Flanges Are Used
Urea Production Plants
High-pressure flange connections in urea synthesis loops
Acid/Alkali Transport Pipelines
Pipeline systems for sulfuric acid, nitric acid, hydrochloric acid, sodium hydroxide, etc.
Storage Tanks and Pressure Vessels
Manway flanges, nozzles, and inspection ports on chemical storage tanks
Heat Exchangers and Reactors
Connection of heat exchanger tubes, condensers, evaporators, and chemical reactors
Certifications






Exhibition
Unlock Bulk Order Savings: Claim Exclusive Pricing for Chemical Stainless Steel Flanges
Our 316L with electropolished surfaces (Ra ≤ 0.8μm) demonstrates exceptional resistance up to 10% concentration at 50°C. For higher concentrations, we recommend Hastelloy C-276® with PTFE-lined gasket surfaces.
All chemical-grade flanges undergo:
- Solution annealing (1040-1120°C quench)
- Ferrite content control (<0.5% for 316L)
- X-ray diffraction residual stress analysis
Yes, we offer:
- Laser-machined serrations (ASME B16.20 compliant)
- Integrated corrosion-resistant spacer designs
- Hybrid graphite/PTFE gasket solutions
Standard: 14 days. Emergency orders: 7 days (using pre-qualified material stock with PMI traceability documentation).
Our 316L/904L/6Mo alloys are:
- Certified for H₂S environments (<15psi partial pressure)
- Hardness-controlled (<22 HRC)
- Full IGC testing (ASTM A262 Practice E)
ASME flanges are widely used in industries such as oil and gas, chemical processing, power generation, water treatment, food processing, and marine applications due to their reliability and adherence to safety standards
Our CNC-machined flanges guarantee:
- 0.05mm/m flatness tolerance
- Surface finish options from 125-600 grit
- 3D optical scanning reports available
All chemical flanges include:
- Mill test certificates
- Liquid penetrant test reports (ASME V Art.6)
- Positive material identification (PMI)
- Heat treatment charts
We implement:
- Insulating kit options (G10 CR grade)
- Sacrificial anode integration
- Noble metal coating compatibility analysis




