Heat Exchanger Integrity Testing

At Unison, we also specialise in non-destructive heat exchanger integrity testing and holding time verification. These solutions allow companies to test their key heat exchangers quickly and effectively, with cutting-edge technology that reduces the risk of product contamination and costly recalls.

Our patented HEIST and Pastest+ systems are the most advanced integrity testing methods on the market. HEIST, the world’s first integrated Heat Exchanger Integrity Self Testing System, means that you are now able to integrity test your Plate Heat Exchangers daily, 365 times a year, rather than the typical 2-4 times annually. By testing before starting production, HEIST greatly reduces the risk of contamination that can occur in between tests along with putting an end to the need to open-up the system on site.

Ultimately, our HEIST system empowers companies to manage their heat exchanger testing so they can reduce safety risks before diving into production. Unison’s solution translates to time and money saved, from completely eliminating the risk of expensive recalls and reducing costs on service repairs, to wasted production and labour.

Unison’s unique technology is revolutionising the way companies test their pasteurisers and plate heat exchangers by providing innovative, cost-effective solutions to everyday problems.



Solve your Quality Control Challenges with Pastest+

It is a well-known fact that every pasteuriser and plate heat exchanger is vulnerable to cracks and other defects during its lifespan. 

These defects may cause severe contamination leading to health problems for consumers and a possible loss of reputation, forcing you to issue costly product recalls.

Of course, detecting these defects is necessary, but it is no easy task as it often requires the equipment to be completely dismantled, causing downtime and loss of production at a significant cost to the business. 

This is where Unison’s Pastest+ can make a difference!

Introducing Pastest+

Validated by Campden BRI, the UK’s leading independent food and drink research organisation, Pastest+ is a non-destructive integrity and holding time test system for pasteurisers and plate heat exchangers.

Pastest+ is transforming process equipment testing worldwide, resulting in substantial cost and time savings. Pastest+ is the only system on the market that can do an integrity test and holding time verification test simultaneously.  Now, you no longer need to worry about costly production downtimes as Pastest+ makes that time-consuming defect detection a reliable and faster process which only takes 1-15 minutes depending on the size of the equipment. This means that several of your key plate heat exchangers can be tested and back in production quicker than ever before. 

Our system only uses the process water supply, thus preventing any saline, compressed air, or chemicals from contaminating the plate heat exchanger during the test.

Pastest+ versus other testing technologies
  1. Specifically designed for heat exchangers rather than repurposed. 
  2. Non-destructive PHE testing technology - no dismantling of plates, with minimum production disruption.
  3. Features an integrated, fully-automatic holding time test facility.
  4. Only uses process water to detect cracks as small as 30 microns. No saline, compressed air, gases or chemicals are introduced into the plate heat exchanger during testing.
  5. Takes just a few minutes.
  6. Immediate results, which greatly reduces downtime.
  7. Test certificates generated automatically by the Pastest+ system.
  8. Campden BRI-validated.
  9. Operator-friendly: compact in design and simple to use.
  10. Results generated via QR code in the newly-launched Pastest+ app.
  11. Comprehensive test and service history of each user’s PHEs stored directly in the Pastest+ app.
Pastest+™: A Seamless Testing Process

Here’s how our seamless testing process works.

Unison’s service engineers run a test on your plate heat exchanger using the Pastest+ app and system, all without dismantling any plates and using only process water.

Capable of detecting small cracks to an accuracy of 30μs, Pastest+ technology detects pressure increases in a closed volume of the plate heat exchanger. If a crack is detected, this will be shown on the Unison App, and a further inspection of the plate pack will be required.

Following the test, a QR code is generated and printed. Using this QR code, you can easily view the automatically generated test result details, which prevents any operator manipulation of the final results.

No more handwritten results.The Pastest+ app automatically stores all of your test results, providing personalised access to your equipment test data. At the same time, it also saves a complete service history of all the customer’s PHEs within the app.


A Superior Testing Solution 

  • Worldwide patented technology 
  • Performs both integrity and holding time tests
  • Designed specifically for heat exchangers
  • More advanced technology than any other system (many of which are outdated and, in some cases, unreliable)
      • Easier to use
      • No risk of introducing outside contaminants 
      • Only uses the customer's process water
      • App-based recording of all data with zero risk of operator manipulation
      • Cost-effective and time-efficient


Pastest+ has been validated by Campden BRI, the UK’s leading independent food and drink research organisation. 

“The test was noted to be rapid,” stated researchers. “The technology was considered to be very effective for simplistic systematic testing the integrity of plate heat exchangers.”