Northern Manufacturing fabricates custom stainless steel and high-nickel alloy equipment for air and water pollution control systems. The equipment we build operates in sustained corrosive environments: acid dew-point conditions in scrubbers, chloride-laden process water in treatment systems, concentrated acid streams in oxidizer off-gas paths. Materials range from 316L for moderate corrosion through duplex 2205/2507 for chloride pitting resistance and Hastelloy C-276 for concentrated acid exposure. All work runs through our 40,000 sq ft stainless-only production space in Oak Harbor, Ohio.
60+ AWS-certified welders. ISO 9001:2015 certified (AVU Registrations). ASME BPVC Section IX qualified welding procedures for austenitic (P8), duplex (P10H), and nickel alloy (P43) base metals. CWI on staff. In-house pickling and passivation per ASTM A380/A967.
Equipment We Build for Pollution Control
- Wet scrubbers and packed-bed absorbers. Gas-contact vessels where the internal surfaces face some of the most aggressive chemical conditions in any plant. Material selection here separates equipment that performs from equipment that corrodes through in two years.
- Quench vessels and oxidizer components. Process vessels and heat exchangers for thermal oxidizer and RTO systems, where rapid temperature cycling and acid condensation attack conventional materials.
- Stack liners and ductwork. Stainless and alloy liners for exhaust stacks exposed to acid dew-point conditions. Weld integrity and alloy selection determine whether a liner lasts a decade or a year.
- Demister housings and mist eliminators. Structural housings for mist-elimination systems in corrosive gas paths.
- Filter housings and dust collector components. Hoppers, support structures, and housings for particulate control systems in corrosive atmospheres.
- Process piping and chemical feed systems. Pipe spools, manifolds, and distribution headers in alloys matched to the process chemistry.
Material Selection for Corrosive Environments
Pollution control equipment fails when the alloy cannot sustain the corrosion mechanism it faces in service. Three failure modes account for most equipment losses:
Chloride stress corrosion cracking (SCC): Standard 304 and even 316L can crack in chloride environments at elevated temperatures. Duplex 2205 resists SCC at chloride levels where austenitic grades fail.
Acid attack: Concentrated sulfuric, hydrochloric, and hydrofluoric acids require alloys engineered specifically for those chemistries. Hastelloy C-276 resists both oxidizing and reducing acids across a wide temperature range.
Pitting and crevice corrosion: Targets weld zones, gasket surfaces, and any geometry that traps stagnant fluid. Duplex 2507 and AL-6XN provide superior pitting resistance in warm chloride environments.
| Grade | Primary corrosion resistance | Typical pollution control use |
|---|---|---|
| 316L | General corrosion, moderate chloride | Structural supports, mild scrubber service |
| Duplex 2205 | Chloride SCC, moderate pitting | Scrubber vessels, wastewater treatment, chemical tanks |
| Duplex 2507 | Severe chloride pitting, hot seawater | Flue-gas desulfurization, high-chloride condensate |
| Hastelloy C-276 | Concentrated acids, wet chlorine gas | Oxidizer off-gas, acid-recovery systems |
Welding in Corrosive Service
Every weld in pollution control equipment is a potential failure point. The heat-affected zone has different metallurgy than the base metal, and in corrosive service, that difference becomes a corrosion pathway.
Northern qualifies welding procedures per ASME BPVC Section IX for each alloy family. For duplex grades, we control interpass temperature and verify ferrite content on production weldments. For nickel alloys, we use low-heat-input GTAW with matching filler to prevent hot cracking and maintain corrosion resistance across the weld.
Contamination Control
A single carbon steel particle embedded in a stainless surface will rust and initiate crevice corrosion. In pollution control service, that small defect becomes a leak path. Northern operates a 40,000 sq ft stainless-only production space with dedicated tooling and consumables. Free-iron verification per ASTM A380 on critical-service assemblies. Post-weld pickling in our 55-foot spray booth restores the passive layer on entire assemblies in one pass.
Quality Documentation
- Material Test Reports (MTRs) with full heat traceability
- Weld maps with WPS/PQR references
- PMI records confirming alloy identity
- NDT reports (RT, UT, PT as specified)
- Ferrite measurement for duplex welds
- Pickling and passivation certification per ASTM A380/A967