In the production of ultrapure water, the Mixed Bed Ion Exchanger serves as the final polishing step. To maintain water quality (typically >15 MΩ·cm), the resin inside these vessels must be periodically regenerated using strong chemicals: Hydrochloric Acid (HCl) for cation resin and Sodium Hydroxide (NaOH) for anion resin.
This regeneration process creates an extremely harsh chemical environment inside the tank. For industrial applications, a standard carbon steel tank without proper protection will corrode within weeks. This is why selecting a high-quality rubber lined ion exchanger, like the Stark STK2 Series, is not just an option—it is a necessity.
The Corrosion Risk: Why Standard Epoxy Isn't Enough
While epoxy coatings are cheaper, they often fail in mixed bed applications due to two factors:
- Thermal Shock: The heat generated during the dilution of NaOH can cause micro-cracks in rigid epoxy coatings.
- Pinholes: Even microscopic pinholes in a thin coating allow acid to attack the carbon steel shell, leading to iron contamination that permanently fouls your expensive resin.
Engineering Fact: Iron fouling (from corroded tank walls) acts as a catalyst for resin degradation. Once your resin is iron-fouled, it loses capacity and requires costly chemical cleaning or total replacement.
Why Stark STK2 Rubber Lined Vessels?
The Stark STK2 Series is specifically engineered for demineralization systems. We combine the mechanical strength of Carbon Steel with the superior chemical resistance of a vulcanized rubber lining.
1. Superior Chemical Resistance
We use a premium rubber lining (typically 3mm - 5mm thickness) that provides a robust barrier against 33% HCl and 40% NaOH. Unlike thin coatings, this rubber layer absorbs thermal expansion and resists mechanical abrasion from resin movement.
2. 100% Spark Tested Integrity
Quality is non-negotiable. Every Stark rubber lined ion exchanger undergoes a high-voltage "Spark Test" before leaving our factory. This ensures there is zero continuity between the lining and the steel shell—guaranteeing a leak-free, corrosion-free service life.
3. Customizable Pressure Ratings
While our standard STK2 models come with 3.0mm to 5.0mm shell thickness for standard operations, we offer full customization. If your project requires ASME-standard high-pressure vessels, our engineering team can increase the shell thickness and flange ratings (DN32 - DN65) to meet your specifications.
Technical Specifications: STK2 Series
Below is the standard selection guide for our Carbon Steel Mixed Bed vessels. Note that for larger diameters, rubber lining is mandatory.
| Model | Flow Rate (m³/h) | Diameter (mm) | Height (mm) | Shell Thickness* | In/Outlet | Recommended Lining |
|---|---|---|---|---|---|---|
| STK-Φ300×2450 | 1 | Φ300 | 2450 | 3.0mm | DN32 | Epoxy (Small Scale) |
| STK-Φ400×2500 | 2 | Φ400 | 2500 | 3.0mm | DN40 | Rubber / Epoxy |
| STK-Φ500×2585 | 3~4 | Φ500 | 2585 | 3.0mm | DN50 | Rubber / Epoxy |
| STK-Φ600×2640 | 5~6 | Φ600 | 2640 | 3.0mm | DN50 | Rubber / Epoxy |
| STK-Φ800×3210 | 8 | Φ800 | 3210 | 4.0mm | DN50 | Rubber / Epoxy |
| STK-Φ1000×3330 | 10 | Φ1000 | 3330 | 4.0mm | DN50 | Rubber / Epoxy |
| STK-Φ1200×3800 | 20 | Φ1200 | 3800 | 4.0mm | DN65 | Rubber Required |
| STK-Φ1500×4000 | 30 | Φ1500 | 4000 | 5.0mm | DN65 | Rubber Required |
*Note: Shell thickness listed is for standard models. High-pressure ASME designs available upon request.
Applications
The STK2 Series is widely trusted in industries requiring critical water purity:
- Boiler Feed Water: Preventing scale and corrosion in high-pressure steam turbines.
- Electronics & Semiconductor: Providing ultra-pure water for wafer cleaning.
- Chemical Processing: Ensuring zero metal ion contamination in process water.
Conclusion
Don't let vessel corrosion compromise your water treatment system. The Stark STK2 Series offers the durability of carbon steel with the advanced protection of industrial rubber lining.
Need help sizing your vessel or require a custom pressure rating? Contact our engineering team today.
