Process Industry
Stainless, Exotic Alloy, and Lined Flange Supply
Chemical plants live with corrosion as a daily fact. Material selection drives every flange decision, and getting it wrong is measured in shutdown hours. Stainless 304 and 316L are the baseline, with duplex and exotic alloys taking over as chemistry demands.
Industry Overview
How Chemical Processing Piping Actually Looks
Stainless 304 and 316L cover the broad middle of chemical service. They handle most organic process streams, intermediate products, and utility piping in a plant where carbon steel would pit out in months.
Severe service pushes the material list into Hastelloy C276 and C22 for chloride and acid combinations, Monel 400 for hydrofluoric acid, Alloy 20 for sulfuric, and duplex 2205 for hot chloride brines. These are not stocked at the same depth as carbon, and lead time planning is part of the design process.
Lined flanges, typically PTFE or PFA over a carbon steel backing, give plants the chemical resistance of an exotic at a fraction of the cost. Bolt torque control on lined joints matters as much as the gasket selection.
Typical Flange Selections
What We Supply for Chemical Processing
Weld Neck, Class 150 and 300
ASME B16.5, F316L and F304L
General process and intermediate product transfer
Hastelloy and Inconel Weld Neck
Class 150 to 600
Chloride and high temperature acid service
Duplex 2205 Weld Neck
ASME B16.5, Class 150 and 300
Hot chloride brines and chloride-rich process water
Lap Joint with Stub End
Stainless or alloy stub, carbon backing
Cost effective alloy piping with reusable flanges
PTFE Lined Flanges
Carbon backing with fluoropolymer liner
Hydrochloric, sulfuric, and aggressive halide service
Blind Flanges
F316L, F304L, and exotic alloys
Vessel manways and isolation points
Material Selection
Common Materials and Why
ASTM A182 F316L
Standard chemical service. Low carbon variant prevents sensitization at weld zones.
ASTM A182 F304L
Lower cost stainless for less aggressive service where chloride exposure is limited.
Hastelloy C276
Wet chlorine, hypochlorite, and mixed acid environments that destroy stainless grades.
Monel 400
Hydrofluoric acid service where most alloys fail rapidly.
Duplex 2205
Hot chloride service with PREN above 35. Cost effective alternative to higher nickel alloys.
Industry Challenges
What Procurement Has to Solve
- 01
Material selection trade-offs between stainless, duplex, exotic alloy, and lined construction at very different price points.
- 02
Bolt torque control on PTFE lined flanges to avoid cold flow and gasket extrusion.
- 03
Lead times on exotic alloys that can stretch into months if not planned around the turnaround calendar.
- 04
Cross contamination prevention during fabrication when stainless and carbon share the same shop.
Standards and Codes
Specifications We Quote To
Ready to Quote Chemical Processing
Tell us the chemistry, temperature, and concentration and we will return a material recommendation with the flange quote.
PO Box 2889, Pearland TX 77588