Industry Solutions

Chemical pipes for Chemical Processing

Acid-specific high-alloy pipe solutions for sulfuric acid, HCl, HF, phosphoric acid, and chlor-alkali plants — selected by media, concentration, and temperature for maximum service life.

Isocorrosion Data Available ASME B31.3 Compliant Seamless & Welded Matching Alloy Fittings
Overview

Corrosion-Resistant Pipes for Chemical Processing Plants

Chemical plants handle hundreds of distinct corrosive media — from concentrated sulfuric acid and hydrochloric acid to phosphoric acid, chlorinated organics, and caustic systems. A one-size-fits-all piping material strategy simply does not work here. At Metinox Overseas, we use an acid-by-acid, temperature-by-temperature material selection methodology — recommending the minimum alloy that delivers 5+ year service life without over-specifying, translating to significant lifecycle cost savings without compromising safety.

Where We Deliver

Key Applications & Grade Rationale

Key Applications

  • Sulfuric acid (H₂SO₄) production and concentration plant piping
  • Hydrochloric acid (HCl) synthesis and distribution lines
  • Phosphoric acid wet-process lines in fertiliser manufacturing
  • Chlor-alkali plant (chlorine, NaOH, HCl) piping systems
  • Nitric acid (HNO₃) production absorption towers and distribution
  • Pharmaceutical intermediate synthesis vessels and transfer lines
  • Caustic soda concentration evaporator tubes and headers
  • Pesticide and dye intermediate processing piping

Why These Grades?

Hastelloy B-3 (UNS N10675) Best-in-class for non-oxidising hydrochloric acid across all concentrations and temperatures — virtually immune to HCl attack.
Hastelloy C-22 (UNS N06022) Superior to C-276 in highly oxidising mixed-acid environments (HNO₃+HF) due to higher Cr and lower Mo.
SMO 254 (UNS S31254) 6% Mo austenitic super-stainless with PREN ≥43; excellent for seawater-cooled process equipment and chloride-rich process streams.
Titanium Gr.2 / Gr.9 Unmatched corrosion resistance in wet chlorine, HNO₃, and oxidising acid service; mandatory in chlor-alkali.
SS 904L (UNS N08904) Cost-effective upgrade from 316L for dilute H₂SO₄ and HCl service up to 50°C in scrubber systems.
Product Range

Recommended Products & Grades

Product Recommended Grades Ideal Application
Hastelloy Pipes & Tubes B-3, C-22, C-276, G-30 HCl, HF, H₂SO₄, mixed-acid, phosphoric acid
Stainless Steel Pipes SS 904L, SMO 254, SS 310S Dilute acid scrubbers, chloride-rich streams, HNO₃
Alloy 20 Pipes UNS N08020 Concentrated H₂SO₄, oleum handling
Duplex Steel Pipes S32205, S32750 Chloride-containing cooling water, brine, scrubbers
Monel 400 Pipes Alloy 400 Hydrofluoric acid (HF) and fluorinated compound lines
Why Choose Us

Key Benefits

Isocorrosion Charts & Lab Data

Acid service alloy selection backed by isocorrosion charts and corrosion lab data for your exact conditions.

Custom Cut & Fabricated Spools

Custom cut lengths, threaded ends, and flanged spools ready for direct plant installation.

Complete Fittings in Matching Alloys

Non-ferrous elbows, tees, and reducers in matching alloys — single-source supply for the full system.

Competitive Exotic Alloy Pricing

Volume purchasing relationships deliver competitive pricing on Hastelloy, Monel, Alloy 20, and SMO grades.

Expert Guidance

Why Metinox Overseas — FAQs

Why Metinox Overseas?

  • Corrosion engineering advisory — we review your P&ID and recommend the cost-optimal alloy
  • Isocorrosion charts and lab data available for acid service alloy selection
  • Custom cut lengths, threaded ends, and flanged spools for direct plant installation
  • Complete non-ferrous fittings in matching alloys
  • Competitive pricing on exotic alloys due to volume purchasing relationships
What is PREN and how does it help select the right stainless grade?
PREN (Pitting Resistance Equivalent Number) = %Cr + 3.3×%Mo + 16×%N. It quantifies a stainless steel's resistance to pitting in chloride environments. Standard 316L has PREN ≈24; duplex 2205 ≈35; super duplex S32750 ≈43. For seawater or concentrated chloride service, a PREN ≥40 is generally required.
Is Monel 400 really suitable for HF acid service?
Yes. Monel 400 is one of the few alloys with demonstrated resistance to anhydrous and aqueous hydrofluoric acid across a wide concentration range. The key limitation is aerated or oxygenated HF, where corrosion rates increase. For HF alkylation units with well-controlled oxygen levels, Monel 400 provides decades of service life.

Custom Alloy Selection for Your Chemical Process?

Share your corrosive media details and operating conditions for a tailored recommendation.

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