Fighting Corrosion: Material Selection for Coalescers in Aggressive Chemical Environments

Fighting Corrosion: Material Selection for Coalescers in Aggressive Chemical Environments

In chemical processing, marine environments, or wastewater treatment, the process fluid itself is the enemy of standard filtration equipment. A Corrosion Resistant Coalescer is defined not just by its media, but by the deliberate, holistic selection of every wetted material to withstand specific chemical attack, ensuring long-term reliability and preventing product contamination.

The Multi-Layered Approach to Corrosion Resistance
We protect your system at every point of contact:

1. Housing & Vessel Material:

• Stainless Steel 316/316L: The workhorse for many chloride and acid environments. We specify low-carbon 316L for welded constructions to prevent carbide precipitation.

• Duplex & Super Duplex Stainless Steels: For higher chloride resistance (e.g., seawater).

• Nickel Alloys (Hastelloy® C-276, Monel®): For severe reducing acids (HCl, sulfuric) and oxidizing salts.

• Non-Metallics: FRP (Fiber Reinforced Plastic), PVDF, or PP lined vessels for highly corrosive or ultra-pure applications where metal ions are unacceptable.

2. Filter Element Construction:

• Cores & Cages: Match the housing material (SS 316L, Alloy 20, etc.) or use engineered plastics like PPS.

• End Caps: Molded from PTFE, PPS, or PVDF for universal chemical resistance.

• Seals: PTFE-encapsulated O-rings, FFKM (Perfluoroelastomer), or Viton® selected based on chemical compatibility charts.

3. Coalescing Media Selection:

• PTFE Membrane & Fibers: The gold standard for broad chemical inertness.

• Polypropylene (PP): Excellent for many acids and bases at moderate temperatures.

• Specialty Glass Fiber: With acid-resistant binder systems.

• Sintered Metal (Hastelloy, Titanium): For extreme conditions.

The Lefilter Process: More Than Just a Material List
We don't guess. Our approach ensures suitability:

1. Chemical Compatibility Analysis: We review your full fluid chemistry (including trace components, pH, and temperature).

2. Application History: We leverage our database of similar successful installations.

3. Third-Party Validation: When in doubt, we recommend or conduct immersion tests on candidate materials.

Key Corrosive Applications:

• Chlor-Alkali Industry: Chlorine, brine, and caustic streams.

• Waste Acid Recovery & Pickling Lines.

• Marine & Offshore: Seawater injection, deck drainage, bilge water.

• Flue Gas Desulfurization (FGD) Scrubber Water.

• Pulp & Paper Mill Bleach Plant Streams.