When it comes to heat exchanger cleaning, the method that is most likely to go wrong is actually not chemical cleaning, but physical cleaning.
Why?
Because many people naturally assume:
"I know how to use a water jet."
"I can dismantle the plates."
"Just spray them clean, right?"
But the reality is different.
Physical cleaning may look like simple manual work, but it is actually one of the easiest ways to damage, deform, or even cause leakage from heat transfer plates if it is done incorrectly.
This article explains the difference between professional physical cleaning and careless cleaning, step by step.
1. Professional Physical Cleaning Does Not Start With a Water Jet
A truly professional cleaning process never starts by immediately spraying the plates with a high-pressure water jet.
The process generally follows this sequence:
- Step 1: Take photos before dismantling and record the plate sequence
- Step 2: Loosen the bolts diagonally and evenly without using excessive force
- Step 3: Remove the plates and inspect them individually for deformation, corrosion, and bulging
- Step 4: Gently scrape off large deposits
- Step 5: Rinse the plates with clean water
- Step 6: Maintain an appropriate spraying angle and pressure during rinsing
- Step 7: Dry the plates, inspect them again, and reassemble the unit
Experienced technicians understand that dismantling, cleaning, and reassembly are all critical stages, and each one is more important than it may appear.
If your idea of physical cleaning is simply putting a water gun against the plate and spraying it back and forth until everything looks clean, you may actually be sending the plates straight toward failure.
2. Common Mistakes That Are Easy to Make in Factory Cleaning
These are some of the most common mistakes I have seen in actual factory maintenance.
In some cases, making just one of these mistakes can mean replacing the heat transfer plates and spending thousands-or even tens of thousands-on repairs.
Mistake 1: Using Excessive Pressure and Cracking the Plates
Many workers believe that higher pressure means better cleaning.
That is a misconception.
Heat transfer plates are relatively thin. When high-pressure water is directed at vulnerable areas such as the plate edges or the bottoms of the corrugation valleys, even slightly excessive pressure can leave visible white marks on the surface.
More seriously, it may create tiny cracks that are difficult to detect with the naked eye.
The result?
The heat exchanger may start leaking after it is reassembled.
Professional approach:
- Keep the water pressure generally within 80–120 bar
- Do not spray directly at the plate surface; use an angled spray
- Use lower pressure and greater care around blind areas and hard-to-reach sections
Mistake 2: Aggressively Scrubbing With a Wire Brush
This is a real plate killer.
Wire brushes are suitable for applications such as cleaning iron cookware or certain floor surfaces. They should not be used to aggressively scrub stainless steel heat transfer plates.
A single cleaning session can leave countless tiny scratches on the plate surface.
These micro-scratches can accelerate corrosion over time and significantly shorten the service life of the plates.
Professional technicians generally avoid wire brushes and instead use:
- Plastic scrapers
- Nylon brushes
- Soft sponges
The key is patience, not brute force.
Mistake 3: Randomly Stacking or Placing the Plates During Dismantling
One of the biggest risks during physical cleaning is not actually the cleaning itself, but the dismantling process.
If the plate sequence is mixed up, the orientation is reversed, or the gasket position is slightly misplaced, it can result in:
- Improper sealing
- Disrupted flow channels
- Uneven pressure distribution
This can eventually lead to air entering the system, fluid cross-contamination, and leakage.
Professional approach:
Take photos before dismantling.
Keep the plates upright and in sequence as they are removed.
During reassembly, check each plate against its number and orientation one by one.
Do not rush the process. Trying to save a few minutes can easily lead to much bigger problems later.
Mistake 4: Failing to Dry the Plates Thoroughly After Cleaning
Even a small amount of residual water between the plates can become trapped inside the gasketed areas after reassembly.
Over time, this trapped moisture can contribute to corrosion.
In fact, some plate corrosion is not caused by the process medium at all-it can result from water trapped between the plates.
Professional approach:
After rinsing, use a combination of air drying and natural drying.
Do not reassemble the heat exchanger until there is no noticeable moisture when the plates are checked by hand.
Mistake 5: Using Physical Cleaning as a Substitute for Chemical Cleaning
Some heavy scale deposits simply cannot be removed by water jetting, no matter how long you keep spraying.
You could keep doing it for years and still not remove them effectively.
In these cases, chemical descaling treatment is required.
Otherwise, continued high-pressure cleaning may gradually thin the plates, making them more vulnerable to damage and failure.
Physical cleaning is mainly suitable for removing surface deposits and light scale layers.
When deep or heavy scaling is present, simply rinsing without dismantling, soaking, or applying the appropriate chemical treatment is essentially a waste of time.
3. What Should You Expect From Professional Physical Cleaning?
The goal is not to make the plates shine like mirrors or look exactly like new.
Those are mostly visual effects.
The real results of professional physical cleaning are:
- Scale and deposits are removed
- Flow channels remain clear
- Heat transfer plates are not damaged
- Gaskets are not pulled or damaged
- The unit does not leak or seep after reassembly
Sounds ordinary?
But achieving all of these results already puts professional cleaning far ahead of the careless cleaning methods commonly used in the field.
Final Thoughts
Physical cleaning is definitely not a matter of simply spraying the plates with water.
It is a double-edged sword: done correctly, it can save money and extend equipment life; done incorrectly, it can damage the equipment and create expensive repair problems.
Professional cleaning depends on technique.
Unprofessional cleaning depends on brute force.
When physical cleaning is done properly, it can help extend the service life of the heat exchanger.
When it is done poorly, it can damage the plates beyond repair.
Physical cleaning is not about who has the strongest water jet or uses the most force.
It is about understanding the plates, the spraying angle, the pressure, and the correct sequence of work.
