PIPINGFLANGE

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.

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, and Alloy 20 for sulfuric. 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, 316L and 304L

General process and intermediate product transfer

Hastelloy and Inconel Weld Neck

Class 150 to 600

Chloride and high temperature acid service

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

316L and exotic alloys

Vessel manways and isolation points

Reducing Flanges

Stainless and alloy

Pump and valve transitions in process headers

Material Selection

Common Materials and Why

316L Stainless

Standard chemical service. Low carbon variant prevents sensitization at weld zones.

304L Stainless

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.

Alloy 20

Sulfuric acid at intermediate concentrations. Specialty grade with limited stocking depth.

Industry Challenges

What Procurement Has to Solve

  • 01

    Material selection trade-offs between stainless, 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 are handled in the same shop.

Standards and Codes

Specifications We Quote To

ASME B16.5
ASME B16.47
ASME B31.3 (process piping)
MSS SP-43 (stainless slip-on)
ASTM A182 (forged alloy)
NACE MR0103

Ready to Quote Chemical Processing

Tell us the chemistry, temperature, and concentration and we will return a material recommendation with the flange quote.

Texas Flange & Fitting Supply | PO Box 2889, Pearland TX 77588