MSF Desalination Plant (Multi-Stage Flash)

MSF is not the oldest technology, but it is the smartest for large projects. But without chemical management, it also has the oldest cost.

In this expert guide, we cover everything about MSF desalination, from how it works and benefits to chemical challenges, scale and corrosion control in simple, practical language. We also show you how to increase efficiency, reduce costs and extend the life of your equipment.

Why read this article?

✅ In-depth understanding of how MSF desalination works

✅ Accurate identification of its chemical challenges — scale, corrosion, reduced efficiency

✅ Learn about the industries that use MSF the most and why

✅ Specialized solutions for scale, corrosion and chemical washing of tanks and condensers

What is MSF desalination?

MSF stands for Multi-Stage Flash. A thermal technology that uses saline water (usually seawater) to produce large volumes of fresh water.

How MSF desalination works

• The brine is first heated to 90 to 110 degrees Celsius in the Brine Heater.
• It then enters a series of Flash Chambers, each operating at a lower pressure than the previous stage.
• In each chamber, a portion of the water is suddenly evaporated (flashed) and the resulting steam is converted into fresh water in internal condensers.
• The concentrated brine is then directed to the next stage to extract the last drop of energy from it.

Key advantage: Very high capacity — suitable for cities, large power plants and huge refineries.

MSF desalination benefits — why is it still used in large projects?

1. Very high production capacity (up to 80,000 cubic meters per day)

• The only technology that can meet the water demand of a metropolis.

2. High reliability and long life (30+ years)

• Old MSF systems in the Persian Gulf still operate at high efficiency — with proper maintenance.

3. No need for membranes or filtration media

• There are no membranes to remove or replace — reducing replacement costs.

4. High resistance to incoming water contamination

• Even with algae, sand, suspended solids or sudden changes in TDS, the system continues to operate.

5. Integration with thermal power plants

• Use of excess steam or recycled hot water — no need for additional fuel consumption.

Chemical Challenges of MSF Desalination

1. Severe corrosion in flash chambers and condensers

• Presence of chlorides, dissolved oxygen and high temperatures → Rapid corrosion of carbon steel and even stainless steel
• Galvanic corrosion at the junction of different metals

2. Scale formation in condensers and Brine Heater pipes

• Formation of calcium carbonate, calcium sulfate and magnesium hydroxide → Reduced heat transfer → Increased energy consumption

3. Decreased efficiency over time

• Without chemical control, system efficiency decreases by up to 40% after 1 year — due to deposited insulating layers and corrosion

4. Need for periodic flushing with specialized chemicals

• Flushing with conventional strong acids → Damage to metals → Leakage and emergency shutdown
• Need for deposition of thermal vectors, non-corrosive and compatible with metals

5. Sensitivity to pH and alkalinity of water

• High pH → Formation of carbonate scale
• Low pH → Acid corrosion
• Need for precise and continuous chemical control

Chamber covered with scale and corrosion in MSF desalination plates

MSF desalination cleaning plate after scale removal

MSF Refinery Desalination Plant

In which industries are MSF desalination plants used? And why?

1. Large urban projects (especially in arid and coastal areas)

• Why?
• Need to produce large volumes of fresh water for a large population
• Access to seawater
• Possibility of integration with hydroelectric or thermal power plants

2. Large thermal power plants

• Why?
• Need to produce high-purity water to feed boilers
• Use of excess steam or recycled hot water
• High capacity and reliability in continuous operation

3. Large oil and gas refineries

• Why?
• Production of high-quality water for injection into wells or process uses
• Tolerance of fluctuations in seawater quality
• No need for complex pretreatment

4. Petrochemical industries with high water consumption

• Why?
• Need to produce process water with very low TDS
• Possibility of integration with steam generation units
• Cost reduction by using recycled heat

Abrizan Company's Specialized Solutions for MSF Water Desalination

We increase the efficiency of your system.

1. Accurately diagnose the type of scale and corrosion with Abrizan's specialized laboratory

Before any action, our laboratory team:

• Takes samples of scale or corrosion in chambers and pipes
• Detects the type of scale and corrosion using XRD, SEM, ICP, Weight Loss Test methods
• Based on the results, recommends a specific Mitreh formulation, not a generic product!

2. Thermal anti-scale injection — Prevents the formation of new scale

- Mitreh products specifically for MSF:

• Controls calcium and magnesium carbonate at high temperatures
• Prevents the formation of calcium sulfate and magnesium hydroxide
• Without creating secondary scale and compatible with steel and copper

3. Periodic chemical washing — with thermal vector precipitation and anti-corrosion mitreh

• Specialized anti-scalants for waters containing compounds such as iron, sulfur, bromine, fluoride, etc.
• Special anti-scalant for high-hardness waters
• Special anti-scalant for seawater and brackish waters
• Standard washing protocol: precise time, dosage, temperature and flow rate — supervised by our technical team

4. Protection of metals with thermal anti-corrosion and pH control

- Anti-corrosion injection to protect:

• Carbon steel
• Stainless steel (SS304, SS316)
• Copper and copper alloys

- High temperature performance and chloride presence — without forming an insulating layer

5. Periodic Monitoring and Performance Reporting

- After each wash, a full report of:

• Reduced operating temperature in the Brine Heater

• Increased thermal efficiency
• Reduced steam consumption
• Increased fresh water production
• Reduced corrosion rate (based on subsequent tests)

All Mitreh products:

• Compliant with API, ASTM, ISO, NACE standards
• No damage to metals — even at high temperatures and in the presence of chloride
• Available as ready-to-use solution or powder — with operating instructions

A team of water treatment specialists performing chemical washing on an MSF unit at the refinery

6. When should the MSF system be flushed?

• 15 to 20% increase in steam or energy consumption
• 15 to 25% decrease in fresh water production
• Increase in Brine temperature at outlet
• Increase in pressure in flash chambers
• Increased vibration or noise in pipes and chambers
• Leakage in joints or welds (due to corrosion)

Golden Tip from Abrizan

Don't wait until your system experiences a significant drop in efficiency or leaks! Periodic flushing (every 6 to 12 months) with a special MSF desalination meter can increase the life of your equipment by up to 2 times and reduce energy costs by up to 30%.

Abrizan's Specialized Services for MSF Desalination

✅Free consultation with the laboratory:

• Send a sediment or corrosion sample → Free analysis → Suggest a specific formulation

✅On-site chemical washing:

• Presence of a specialist team in your project — Implementation of a standard protocol — Performance report

✅Supply of Mitreh products:

• Thermal anti-scaling — Sediment remover — Anti-corrosion — pH control
• Shipping to all parts of Iran — with Persian executive guide

✅Operational training for operators:

• How to inject materials — Control parameters — Washing schedule — Performance monitoring

[Request free technical advice and analysis and direct contact with a sales expert]

Final summary:

MSF desalination plant is a large-scale and sustainable technology, but without proper chemical management, it becomes a source of cost, risk of leakage and reduced efficiency.

Abrizan Industrial Research Company with the Mitreh brand, relying on experience, laboratory and expert executive team, is ready to be with you to increase thermal efficiency, reduce energy consumption, prevent leakage and extend the life of equipment.