S5 · Wet FGD Desulfurization

Wet FGD Desulfurization (2507/904L Medium and Boundary List)

List out the media, grades, and boundary conditions related to wet FGD desulfurization: 3 typical components/processes, including recommended grades, specifications, failure reasons, and standards.

Explain the operating condition and get material selection advice View Products

Stainless Steel Flues and Absorbers for Power Plant Desulfurization Systems — Power and Environment: Flues, absorbers, and heat exchangers (Illustration; actual selection based on media, temperature, and drawings)

3 Parts and Material List

Part / Component	Recommended Grade	Specification / Thickness	Surface	Main failure modes	Reference standards
FGD outlet flue gas condensate	2507/2205/316L/304L	Water saturation + solid-liquid droplets + Cl⁻/SO₄²⁻	Corrosion rate ranking: 2507 < 2205 < TA2 < 316L; 2205/2507 insignificantly different; 304L/316L noticeable corrosion	Spray layer / mist eliminator / flue gas duct lining preferentially 2205/2507; extreme local selection 254NM/AL-6XN	ASTM A240；DL/T 5196
Sulfuric acid environment (not FGD but often confused)	2507/904L/254SMO	H₂SO₄ 20–40%	Corrosion rate of 2507 at 40% H₂SO₄ > 50 mm/a; 904L/254SMO better with 904L/254SMO	When sulfuric acid concentration and temperature exceed 2507, upgrade to 904L/254SMO, not using duplex steel	ASTM A240; equivalent corrosion charts
FGD absorber / wet/dry inlet flue gas duct alternation	254NM/AL-6XN/904L/C276/C22	High Cl⁻ concentration + pH 2–5 + 50–160℃	316L perforates quickly at the dry/wet interface; localized high-alloy pitting/SCC	High-alloy concentrate severe local areas	ASTM A240/B575；DL/T 5196

Table is forStandard configuratieSpecify material based on usage conditions.

Key considerations in selection

Most common grades used: 2507 (2), 904L (2), 304L (1) —— Numbers in parentheses indicate the number of parts involved, useful for quoting and material ordering.
Thickness range: 2–160 mm —— For thin plates, consider springback and deep drawing cracks; for thick plates, consider heat input and sensitization.

What are common questions?

Wet FGD desulfurization: 2205/2507/254NM/904L Which stainless steel is used the most for corrosion rate ranking?

Total pages, count these 3 parts. The most frequent is 2507 (2), 904L (2), and 304L (1). Specific to a part still depends on the medium and temperature, like stainless countertops, contact with salt water should switch from 304 to 316L.

What part is easiest to have problems?

Failure description, typically "FGD condensate from flue gas": Spray tower/scrubber/liner priority 2205/2507; extreme local selection 254NM/AL-6XN; recommended grades 2507/2205/316L/304L, specification water-saturated + solid+Cl⁻/SO₄²⁻. This type of condition recommends specifying medium concentration, temperature, and cleaning method during the design phase.

What thickness should I select?

Thickness range in the list is 2–160 mm. For thin sections, consider bending and surface finish; for thick sections, welding and structural strength. Values may vary by manufacturer for the same location, review your drawing or operating conditions.

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