Safety first. Isolate, drain and depressurise both sides and let the unit cool before you loosen the pack. Treat any suspected mixing as a food safety issue under your site's quality procedure.
Symptoms
- Drips or spray from the plate pack edge.
- Water in the product, or product in the cooling or heating water.
- Unexpected conductivity, solids or test results downstream.
- Leaks that start after a CIP or a temperature change.
Likely causes
- Gasket wear and attack. Gaskets harden, crack or swell with age, heat and cleaning chemicals.
- Wrong tightening. A plate pack tightened outside the dimension on the nameplate leaks or crushes gaskets.
- Pressure shocks. Water hammer, fast valve closing or pump start-up can open the gasket seal.
- Plate cracks and pinholes. Fatigue, corrosion or chloride attack can make small holes that let media mix.
- Wrong pressure balance. If service media pressure is higher than product pressure, a hole lets service media into the product.
What to check, in order
- Mark where the leak appears on the pack, and at which temperature or pressure it starts.
- Measure the plate pack tightening dimension and compare it with the nameplate or service documentation.
- Inspect gaskets for cracks, hardness and seating at the next opening.
- If you suspect mixing, test for it with the method used at your site, such as a pressure test or dye check.
- Check that product-side pressure is kept higher than service-side pressure where your process requires it.
- Review recent changes to CIP chemicals, concentrations or temperatures.
When to call a TPS engineer
Call a TPS engineer if you find mixing between media, cracked plates, or a leak that returns after re-gasketing. Product safety may be affected.
Ask LiveAccess
Photograph the nameplate and the leak position, and ask for the tightening dimension and gasket type. In the app you can also find a liquid processing expert in the Expert Network and chat or call them.
This guide gives general checks. Settings, limits and procedures differ between machines: always use the values in your service documentation and your site procedures.
