Checking heat exchangers for leaks

for the dairy industry

Order checking the tightness of heat exchangers for dairies from Viravix Engineering. We test equipment for leaks using the N2H2 gas test. This is a quick way to find microscopic cracks in a heat exchanger without disassembling the equipment, with 99% accuracy.
Проверка теплообменника на герметичность
Engineering practices play a vital role in ensuring the bacteriological purity and overall quality of milk.

Heat exchangers are essential in milk processing, serving crucial functions such as heating, pasteurization, and cooling. Maintaining the optimal temperature throughout these processes is paramount to guaranteeing the excellence of the final dairy product.

Heat exchangers are subjected to harsh operating conditions that increase their susceptibility to wear and corrosion. Factors like:

  • aggressive chemical environments; high humidity;
  • water hammer;
  • vibrations.
contribute to the deterioration of heat exchangers. Even a minuscule, imperceptible micro-crack can result in a catastrophic failure of the heat exchanger.
By implementing regular rechecking the tightness of heat exhangers, the dairy industry can prioritize milk quality, minimize risks, and maintain a positive reputation.

The consequences of a defective heat exchanger extend beyond equipment failure. The presence of pathogenic microorganisms can proliferate in the finished milk product, posing significant risks to its safety. This increases the likelihood of spoilage, product returns, and customer complaints, leading to substantial financial losses, potential legal issues, and damage to the company’s reputation.

To mitigate these risks, regular rechecking the heat exchangers for tightness is essential. This re-verification of heat exchangers, carried out by employing engineering techniques, ensures the integrity of the heat exchanger’s structure. By confirming that the heat exchanger remains tightly sealed, manufacturers can uphold the bacteriological purity of milk, maintain product quality, and prevent potential financial, legal, and reputational losses

Types of damage caused to plate heat exchangers

Regular leak tests help to identify and repair pitting and micro-cracks in time to prevent total destruction of the plates
Seek leaks if:

  • the capacity has dropped at the same time as the heating medium and electricity consumption has increased;
  • the equipment has been idle for an extended period of time;
  • the heat exchanger is being commissioned after repair or modernisation.

How to spot a hidden defect

Viravix Engineering searches for leaks with the N2H2 gas test. A mixture of hydrogen and nitrogen is fed under pressure through a plate heat exchanger. Special sensors detect gas leaks and can detect micro-cracks, pitting or seal failures. The test is 99% accurate.
1,5 hours
Heat exchanger audit
per section
4 hours
Detailed report ready
Как проверить теплообменник
 Leak detection guarantee
Average cost 
per 1 section test
Gas testing technology without equipment disassembling​
Video on performing a heat exchanger gas test
Gas tests of heat exchangers are also carried out using helium, but this is an expensive and scarce resource. In addition, it dissipates more slowly into the ambient air, which increases the likelihood of false positives for latent defects when examining multiple sections.
Test steps
  1. CIP washing of the heat exchanger is carried out.
  2. The pipes are disconnected.
  1. A gas mixture is started on one side of the heat exchanger: hydrogen 10% + nitrogen 90%. On the other side, a diaphragm pump presses air into the closed circuit.
  2. Hydrogen molecules will penetrate to the circulation side of the air mixture if there is damage in the section. The instrument will record the size and speed of the leakage. Based on this the size of the defect is determined.
  3. After the section has been checked, the seals are tested.
The customer will receive :
  • confirmation of the presence or absence of defects;
  • the size and description of the damage;
  • photo fixation of the leakage defects;
  • recommendations for repairing the damage and further operation of the heat exchanger.

Why a gas test is better than a disassembly

Operators often disassemble the heat exchanger to check for leaks visually.
The direct costs of dismantling equipment are cheaper than non-destructive testing methods.
Disassembling a heat exchanger does not save on production scale for a number of reasons:

  • Equipment downtime takes up to three days;
  • Increased labour costs for the personnel;
  • Even usable seals have to be replaced, and these cost from 7000 euros per set;
  • There is a risk of damaging the plates.
In addition, there are plate heat exchangers that cannot be disassembled. And visual inspection cannot detect pitting and micro-cracks.

Table comparing heat exchanger testing methods

Testing methods
Hydraulic proof test
Hydrochemical test
Dye-penetrant test
Gas test N2H2

Microcrack ​

< 30 microns​

Microcrack ​

> 30 microns

For the operating company, non-destructive testing methods are more advantageous as they provide more accurate results and do not damage the equipment.

Benefits of the GasTest N2H2 to check the heat exchanger

Viravix Engineering
Viravix Engineering
  • check
    The margin of error is as low as 1%. It is the most accurate method now available.
  • check

    A non-flammable and non-toxic gas mixture is used, which does not contaminate the heat exchanger. The N2H2 gas test is suitable for the dairy industry. The methodology eliminates media overflow and dilution of the refrigerant, and minimises user error.

  • check

    The dye or hydraulic test requires water, increasing its consumption for purposes unrelated to finished product manufacture. Gas testing is energy efficient.

    Highly sensitive equipment does most of the work. The labour required by the operating staff is reduced by up to 95%, as no disassembly of the equipment is required.

  • check
    Downtime of the heat exchanger is minimal compared with disassembly. Inspection of one section takes 15 minutes. We use flexible hoses for mixture and air supply, so that tests can even be carried out on equipment that is difficult to access.
Contact Viravix Engineering to find out more about the gas test or to book a heat exchanger leak test.