Materials selection from chemical compatibility databases, corrosion rate analysis, and accelerated life testing. The right material for your chemical environment, not the one in stock. This is how equipment lasts decades instead of years.
Custom automation and SCADA integration for critical water treatment processes plants.
Seamlessly integrate new water treatment equipment with your existing infrastructure.
Complete turnkey water treatment plants from initial concept through commissioning.
Comprehensive support packages including preventive maintenance, remote diagnostics, operator training and genuine spare parts.
Materials engineering that extends equipment life and prevents catastrophic failure
Material failure in wastewater equipment is rarely sudden. It is the accumulation of corrosion, erosion, and stress over months and years that eventually causes leakage, structural compromise, and unplanned shutdown. The cost of replacing a failed vessel far exceeds the cost of specifying the correct material at the outset. Our materials engineering team selects every grade from chemical compatibility databases, corrosion rate data, and accelerated life testing, ensuring that your equipment is fabricated from materials that will endure your specific chemical environment for the design lifetime.
Materials are selected from comprehensive chemical compatibility databases that account for pH, chloride concentration, oxidising agents, temperature, and mixed chemical environments. Not guesswork. Data.
Corrosion rates are predicted from published data, laboratory testing, and field experience. Wall thickness, corrosion allowance, and inspection intervals are all calculated from quantified rates.
Material coupons are exposed to simulated process conditions at elevated temperature and concentration to accelerate failure modes. The data validates compatibility predictions and identifies unexpected degradation mechanisms.
The right material for every wastewater chemistry
| Environment | Primary Concern | Recommended Materials | Corrosion Mechanism |
|---|---|---|---|
| Municipal Sewage | Chlorides, H±0.2S, organic acids | 316L, 304, duplex 2205 | Pitting, general corrosion |
| Food Processing | Chlorides, fats, organic acids | 316L, 904L, duplex 2205 | Crevice corrosion, pitting |
| Chemical Plant | Strong acids, oxidants, solvents | Hastelloy C276, titanium, 904L | General corrosion, SCC |
| Oil & Gas Produced Water | High chlorides, H±0.2S, CO±0.2 | Duplex 2507, super duplex, 6Mo | Pitting, SSC, SCC |
| Marine / Seawater | High salinity, biofouling | Titanium, super duplex, 6Mo | Pitting, crevice, MIC |
| Mining Acid Drainage | Low pH, sulphates, heavy metals | Hastelloy C276, rubber-lined steel | General corrosion, erosion |
| Pharmaceutical | API residues, sanitising agents | 316L electropolished, 904L | Pitting, stress corrosion |
| High Temperature | Oxidation, thermal cycling | 310S, 253MA, Inconel 625 | Oxidation, carburisation |
Selection depends on exact chemical composition, temperature, and operational history. Laboratory testing recommended for mixed or uncertain environments.
We characterise corrosion behaviour using standard electrochemical techniques to quantify rates and identify mechanisms:
Critical design criterion: Erp must exceed the maximum expected open-circuit potential by +50 mV minimum to ensure repassivation after a pitting event.
| Mechanism | Trigger | Affected Materials | Mitigation |
|---|---|---|---|
| Uniform corrosion | Low pH, high conductivity | Carbon steel, zinc | Coatings, cathodic protection |
| Pitting | Cl⁻ > 200 mg/L, temp >40 °C | 304, 316 (if PREN low) | Mo-bearing alloys, coatings |
| Crevice corrosion | Stagnant zones, gaskets | 316L, 304 | Duplex, design geometry |
| SCC | Cl⁻ + tensile stress >60 °C | Austenitic SS | Duplex, stress relief |
| Galvanic | Dissimilar metal contact | Less noble member | Insulation, sacrificial anode |
| MIC | SRB, iron-oxidising bacteria | Carbon steel, SS | Biocide, CP, material upgrade |
| Erosion-corrosion | High velocity + solids | Carbon steel, Cu alloys | HRC coatings, velocity limits |
For carbon steel tanks and pipelines in aggressive soils or immersion, impressed current cathodic protection (ICCP) or sacrificial anode systems are designed per EN 12954 and NACE SP0169. The required protection current density is typically 10–30 mA/m² for coated steel in aerated water, and 50–100 mA/m² for bare steel in anaerobic conditions. The anode mass is calculated from Faraday's law: M = (I × t × 8760) / (ε × q), where M is anode mass (kg), I is current (A), t is design life (years), ε is anode utilisation factor (0.85 for magnesium, 0.90 for zinc), and q is anode electrochemical capacity (1,230 Ah/kg for Mg, 780 Ah/kg for Zn). Potential monitoring confirms protection: steel potential must be maintained between −850 mV and −1,050 mV vs. Cu/CuSO₄ reference electrode.
ASTM G31 immersion tests run at elevated temperature (Ttest = Toperating + 20 °C) and concentrated chemistry to accelerate degradation. Corrosion rates are Arrhenius-corrected back to operating temperature using activation energies of 40–60 kJ/mol for aqueous corrosion. Testing duration: 30 days minimum for screening; 90 days for life prediction. Coupons are examined by SEM/EDX to identify pit morphology and corrosion product chemistry.
Electropolishing reduces surface Ra to 0.2–0.4 μm, removes embedded iron, and enriches the surface chromium layer, improving pitting resistance by 20–30%. Nitric acid passivation (20–25% HNO₃, 50–60 °C, 30 min) per ASTM A967 restores the passive film after fabrication. For duplex stainless, a proprietary nitric-hydrofluoric pickle (5% HNO₃ + 2% HF) removes weld oxide and restores the 50/50 phase balance at the surface.
Every water treatment challenge is unique. Our bespoke engineering team designs, fabricates, and commissions custom equipment and systems that standard products cannot address. From exotic material selection to extreme duty specifications, space-constrained layouts, and integration with legacy control systems, we deliver solutions that work in your specific operational context.
3D CAD modelling and CFD simulation validate performance before fabrication commences.
SS304, SS316L, duplex, and exotic alloy welding and machining in our European workshops.
Control systems communicate with your existing SCADA, DCS, and PLC infrastructure.
Complete design dossier, HAZOP, FAT/SAT protocols, and O&M manuals provided.
Site survey, water analysis, and process requirement definition with your engineers.
Process flow diagram, P&ID, and 3D layout with performance guarantees and budget estimate.
Mechanical, electrical, and control design with material specifications and vendor selection.
Workshop construction with QA/QC inspection, weld records, and pressure testing.
Logistics, cranage, mechanical installation, and pipework connection by our teams.
FAT, SAT, performance trials, operator training, and handover documentation.
Standard corrosion-resistant stainless for municipal, food, and general industrial applications.
Superior chloride resistance for marine, offshore, and high-salinity process waters.
Maximum corrosion resistance for extreme chloride, sour gas, and high-temperature duties.
Hastelloy, Inconel, and titanium for aggressive chemistries and ultra-high purity requirements.
Custom SS316L reaction vessels and solvent recovery distillation column for a European API manufacturer. Project delivered on budget with full GMP documentation.
Super duplex seawater intake and process water treatment skids for an African copper mine. Designed for 25-year life in corrosive groundwater.
Compact lamella clarifier and DAF retrofit within an existing 1960s WWTP building. Zero downtime installation with bypass architecture.
Containerised TBM slurry treatment plant processing 1,200 m³/h of bentonite slurry. Mobile design relocated three times during project lifecycle.
Speak with our corrosion engineers to analyse your effluent chemistry and specify the optimal material grade, surface finish, and corrosion allowance for your equipment.
Our expertise spans multiple industries with sector-specific water treatment solutions.