Acid Dew Point & 60 Industrial Chemicals Resistance Selector
Material selection guide for Flue Gas Desulfurization (FGD), incineration, and chemical ductwork across liquid acid phase (T ≤ T_dew) and dry vapor phase (T > T_dew).
Verhoff-Banchero Flue Gas Acid Dew Point Formula
In fossil fuel boilers and incinerators, fuel sulfur oxidizes to SO2 and SO3. Combined with moisture, gaseous sulfuric acid forms. The Verhoff-Banchero correlation predicts the exact dew point temperature:
Under typical flue gas conditions, acid condensation initiates between 130°C and 150°C (266°F to 302°F). Below this threshold, condensing liquid H2SO4 dissolves unlined ducting. BundleTec ChemTec utilizes a 100% sintered cross-film PTFE membrane to ensure zero chemical degradation.
| Industrial Chemical / Formula | Category | PTFE (Sintered / Cross-Film) Liq / Gas |
FKM (Fluoroelastomer) Liq / Gas |
Silicone (VMQ) Liq / Gas |
E-Glass Scrim Liq / Gas |
|---|---|---|---|---|---|
|
Sulfuric Acid
H2SO4
|
Acids | A / A | B / A | D / C | D / B |
|
Hydrochloric Acid
HCl
|
Acids | A / A | A / A | D / C | C / B |
|
Hydrofluoric Acid
HF
|
Acids | A / A | B / A | D / D | D / D |
|
Nitric Acid
HNO3
|
Acids | A / A | B / A | D / C | C / B |
|
Phosphoric Acid
H3PO4
|
Acids | A / A | A / A | C / B | C / B |
|
Sulfurous Acid
H2SO3
|
Acids | A / A | A / A | C / B | C / B |
|
Formic Acid
HCOOH
|
Acids | A / A | B / B | C / B | B / A |
|
Acetic Acid (Glacial)
CH3COOH
|
Acids | A / A | C / B | B / A | B / A |
|
Carbonic Acid
H2CO3
|
Acids | A / A | A / A | A / A | A / A |
|
Citric Acid
C6H8O7
|
Acids | A / A | A / A | B / A | B / A |
|
Sulfur Dioxide
SO2
|
Gases & Oxides | A / A | A / A | B / A | B / A |
|
Sulfur Trioxide
SO3
|
Gases & Oxides | A / A | B / A | D / C | D / B |
|
Nitric Oxide
NO
|
Gases & Oxides | A / A | B / A | C / B | B / A |
|
Nitrogen Dioxide
NO2
|
Gases & Oxides | A / A | B / A | D / C | C / B |
|
Nitrous Oxide
N2O
|
Gases & Oxides | A / A | A / A | B / A | A / A |
|
Carbon Monoxide
CO
|
Gases & Oxides | A / A | A / A | A / A | A / A |
|
Carbon Dioxide
CO2
|
Gases & Oxides | A / A | A / A | A / A | A / A |
|
Hydrogen Sulfide
H2S
|
Gases & Oxides | A / A | B / A | C / B | B / A |
|
Ammonia Vapor
NH3 (dry)
|
Gases & Oxides | A / A | D / C | B / A | A / A |
|
Chlorine Gas (Dry)
Cl2 (gas)
|
Gases & Oxides | A / A | A / A | D / C | B / A |
|
Wet Chlorine Vapor
Cl2 (wet)
|
Halogens | A / A | B / A | D / D | C / B |
|
Chlorine Dioxide
ClO2
|
Halogens | A / A | B / B | D / C | C / B |
|
Hydrogen Bromide
HBr
|
Halogens | A / A | A / A | D / C | C / B |
|
Bromine Vapor
Br2
|
Halogens | A / A | A / A | D / D | C / B |
|
Fluorine Gas
F2
|
Halogens | B / B | D / D | D / D | D / D |
|
Phosgene
COCl2
|
Halogens | A / A | B / A | D / C | B / A |
|
Silicon Tetrafluoride
SiF4
|
Halogens | A / A | B / A | D / C | D / C |
|
Thionyl Chloride
SOCl2
|
Halogens | A / A | B / B | D / D | C / B |
|
Sodium Hydroxide (Caustic)
NaOH
|
Alkalis | A / A | D / C | C / B | D / B |
|
Potassium Hydroxide
KOH
|
Alkalis | A / A | D / C | C / B | D / B |
|
Calcium Hydroxide (Lime)
Ca(OH)2
|
Alkalis | A / A | B / A | B / A | B / A |
|
Ammonium Hydroxide
NH4OH
|
Alkalis | A / A | D / C | B / A | A / A |
|
Sodium Carbonate
Na2CO3
|
Alkalis | A / A | A / A | B / A | B / A |
|
Magnesium Hydroxide
Mg(OH)2
|
Alkalis | A / A | A / A | B / A | A / A |
|
Triethanolamine (TEA)
C6H15NO3
|
Alkalis | A / A | D / C | B / A | A / A |
|
Cement Clinker Dust
CaO·SiO2·Al2O3
|
Abrasive Dust | A / A | A / A | B / B | A / A |
|
Fly Ash (Coal Combustion)
SiO2-Al2O3-Fe2O3
|
Abrasive Dust | A / A | A / A | B / B | A / A |
|
Silica Sand / Quartz Dust
SiO2
|
Abrasive Dust | A / A | A / A | A / A | A / A |
|
Pulverized Coal Dust
C (Carbon)
|
Abrasive Dust | A / A | A / A | A / A | A / A |
|
Lime Kiln Dust
CaO
|
Abrasive Dust | A / A | A / A | B / A | A / A |
|
Fluid Catalytic Cracking Dust
FCC Catalyst
|
Abrasive Dust | A / A | A / A | B / A | A / A |
|
Blast Furnace Dust
Fe2O3+C+SiO2
|
Abrasive Dust | A / A | A / A | B / A | A / A |
|
Carbon Black / Soot
C
|
Abrasive Dust | A / A | A / A | A / A | A / A |
|
Toluene
C7H8
|
Solvents | A / A | B / A | D / C | A / A |
|
Xylene
C8H10
|
Solvents | A / A | B / A | D / C | A / A |
|
Benzene
C6H6
|
Solvents | A / A | B / A | D / C | A / A |
|
Acetone
C3H6O
|
Solvents | A / A | D / C | C / B | A / A |
|
Methanol
CH3OH
|
Solvents | A / A | C / B | B / A | A / A |
|
Ethanol
C2H5OH
|
Solvents | A / A | B / A | B / A | A / A |
|
Methyl Ethyl Ketone (MEK)
C4H8O
|
Solvents | A / A | D / D | C / B | A / A |
|
Diesel Fuel Vapor
C10-C15
|
Solvents | A / A | A / A | D / C | A / A |
|
Kerosene
C12-C15
|
Solvents | A / A | A / A | D / C | A / A |
|
Biogas (Methane + H2S)
CH4 + H2S
|
Solvents | A / A | B / A | C / B | A / A |
|
Syngas (CO + H2)
CO + H2
|
Solvents | A / A | A / A | B / A | A / A |
|
Wet FGD Scrubber Slurry
CaSO4 + H2SO4
|
Moisture / Steam | A / A | B / A | D / C | D / B |
|
Acid Flue Gas Condensate
pH 0.5 - 2.0
|
Moisture / Steam | A / A | B / A | D / C | D / C |
|
Saturated Steam
H2O (steam)
|
Moisture / Steam | A / A | B / B | C / B | C / A |
|
Demineralized Water Vapor
H2O (pure)
|
Moisture / Steam | A / A | A / A | B / A | A / A |
|
Marine Salt Spray
NaCl + H2O
|
Moisture / Steam | A / A | A / A | A / A | A / A |
|
Incinerator Waste Flue Gas
HCl+HF+SOx+NOx
|
Moisture / Steam | A / A | B / A | D / D | D / C |
ChemTec Series: 100% Pure Sintered PTFE Gas Barrier
Engineered specifically for wet FGD scrubber ductwork, providing complete molecular impermeability across full pH 0–14 environments.
Acid Dew Point & Chemical Corrosion FAQ
What is acid dew point and why is it critical in fabric expansion joint engineering? +
In flue gas containing sulfur oxides (SO2/SO3) and water vapor, sulfuric acid vapors condense into concentrated liquid droplets when temperature drops below 130°C to 150°C. This aggressive liquid acid phase rapidly degrades non-PTFE materials and causes catastrophic joint failure.
How does PTFE compare against FKM and Silicone in chemical resistance? +
Sintered cross-film PTFE is chemically inert across the entire pH 0–14 spectrum in both liquid acid and dry vapor phases. FKM resists most dry acids but degrades in hot alkalis and ketones. Silicone degrades severely when exposed to liquid condensing acids below the dew point.
Why does Hydrofluoric Acid (HF) require special fluoropolymer encapsulation? +
HF dissolves silica-based fiberglass (E-Glass) structural reinforcements. In HF-bearing incinerator and chemical ducts, BundleTec implements hermetically sealed, sintered multi-layer PTFE envelopes that isolate the glass reinforcement from chemical contact.