The New 3021 Pressure Vessel by CobrAm
A Real Game Changer in Marine Watermakers
We are proud to introduce the new CobrAm 3021 pressure vessel, engineered in Austria and 100% Made in EU.
This is not a cosmetic update. This is not a new display, a different housing, or another control interface.
This is a fundamental improvement in the core of the watermaker itself.
Why This Is a True Innovation
In recent years, the marine desalination market has seen very little real innovation. Most systems still rely on the same concepts introduced decades ago: the same 2.5″ × 40″ pressure vessels, minor aesthetic updates, and more attractive touchscreens — but no real evolution of the hydraulic components.
At CobrAm, we believe that real progress comes from engineering, not from cosmetics. That is why we decided to rethink the most critical component of a watermaker: the pressure vessel and the way water flows through multiple membranes.
Why We Dislike 2.5″ × 40″ Pressure Vessels (2540)
Even though 2540 vessels are still widely used (including in many legacy systems), they have clear limitations:
- Bulky: typically 125–130 cm long including fittings
- Heavy: stainless end caps add weight — a 4-vessel rack for ~250 l/h can reach ~30 kg
- Costly to ship: oversized dimensions increase logistics complexity and costs
- Hydraulically inefficient: feed and brine ports are limited to 1/4″. In multi-membrane systems,
downstream membranes operate worse due to severe restrictions. On 1/4″ fittings, there is no meaningful way to improve this.
A Completely New Approach: The 3″ × 21″ Concept (3021)
Instead of accepting these limits, we designed a new pressure vessel around standard 3″ × 21″ membranes.
Our goals were clear:
Shorter and More Compact
- Length reduced from 40″ to 21″
- Total length including fittings: 84 cm vs. ~125 cm for a typical 2540
- One third of the length eliminated
Practically the Same External Size
- The new 3″ vessel is only ~1 cm taller than a 2.5″ vessel
- End plate dimensions: 11 × 11 cm instead of 10 × 10 cm
Lightweight and Easy to Handle
- Custom Delrin® end caps developed by CobrAm
- Lightweight, mechanically strong, corrosion-free
- Ideal for marine environments and long-term reliability
Same Membrane Surface Area
- The 3021 membrane provides equivalent effective surface area to a 2540
- Same nominal production capability
- Better real-world performance in multi-membrane systems due to improved flow distribution (especially after the first membrane)
The Real Game Changer: Hydraulic Efficiency
This is where the breakthrough happens. Thanks to a completely new end-cap design, fully engineered by our R&D team, we introduced:
3/4″ Feed and Brine Ports
Compared to traditional 1/4″ ports, the internal flow cross-section is:
9 times larger (+800% area)
This single design change transforms the behaviour of multi-membrane systems:
- Much lower pressure losses
- More uniform flow across all membranes
- Downstream membranes operate at optimal conditions
- Significantly lower energy consumption for the same water output
What This Means in Real Numbers
Example 1 – 250 l/h production
- New system: 3 × 3021 membranes + 1500 W motor
- Previous system: 4 × 2540 membranes + 2200 W motor
Example 2 – 140 l/h production
- New system: 3 × 3021 membranes + 750 W motor
- Previous system: 2 × 2540 membranes + 1500 W motor (150 l/h)
- Performance unreachable with traditional 2.5″ systems and 750 W motor
The Result
- Lower energy consumption
- Higher hydraulic efficiency
- Fewer membranes required
- Shorter, lighter racks
- Easier installation on board
- Lower shipping and logistics costs
This is not an incremental improvement. It is a new generation of pressure vessels, designed to bring real innovation back into marine desalination systems.
2540 vs 3021 – What Changes in the Real World
On paper, 2540 and 3021 membranes can offer similar nominal surface area. In real installations, the system performance is heavily influenced by hydraulic efficiency — especially in multi-membrane configurations.
That is exactly where the 3021 vessel concept delivers a major advantage.
Quick Comparison
| Feature | Traditional 2540 (2.5″ × 40″) | CobrAm 3021 (3″ × 21″) |
|---|---|---|
| Overall length (incl. fittings) | ~125–130 cm | 84 cm (about 1/3 shorter) |
| External footprint | Compact | Almost identical (only ~1 cm taller) |
| End caps | Often stainless steel (heavier) | Custom Delrin® (lighter, corrosion-free) |
| Feed & brine ports | 1/4″ | 3/4″ |
| Flow cross-section | Baseline | 9× larger (+800% area) |
| Multi-membrane efficiency | Downstream membranes suffer restrictions | Uniform flow across all membranes |
| Energy for 250 l/h (example) | 4 × 2540 + 2200 W | 3 × 3021 + 1500 W |
| 140 l/h (example) | Not realistically achievable at low power | 3 × 3021 + 750 W |
| Shipping & installation | Long and awkward to handle | Shorter, lighter, easier |
Why It Matters
- Less pressure loss means more usable pressure at the membranes
- More uniform flow means every membrane works closer to its optimum
- Lower power required means easier integration on board (generators, inverters, battery banks)
- Shorter racks open new installation options in tight engine rooms
The outcome is simple: more production per Watt, fewer membranes for the same output, and a system that is easier to install, ship, and service.