SONDEX® semi-welded plate heat exchangers

SONDEX® semi-welded plate heat exchangers are the prime choice for challenging applications that involve aggressive media or high pressure. The semi-welded plate heat exchangers are very versatile which means that they can easily be configured for use in different industries and applications that involve challenging media, such as chemical processing.

We customize each heat exchanger according to your specifications and offer durable solutions designed to withstand extreme conditions and minimize the risks of operation.

You can safely operate with hazardous or aggressive media, high pressure, or extreme temperatures that are unsuitable for regular fully gasketed heat exchangers. We design to give you peace of mind. 

Features and benefits

  • High efficiency means that fewer plates are needed for high performance and consequently lowers the hold-up volume. Fewer plates also lowers the cost of each heat exchanger, as an added bonus.
  • Engineered to use smaller amounts of potentially hazardous media, the SONDEX®semi-welded range is a safe and responsible choice for demanding duties.
  • Unique gasket system intended for high working pressures and vacuum applications. A closed gasket groove keeps the gasket firmly in place and prevents misalignment of the plate pack during assembly and operation.

Technical specifications

  • Connections from DN65 to DN500 (2½" to 20")
  • (Frames designed according to FEA and PED 2014/68/EU (EN13445) and ASME sec VIII, Div. 1 construction standards)
  • Plate materials: AISI 304/316, titanium, SMO, Hastelloy*
  • Gasket materials: EPDM-HT, NBR-HT, Viton*
  • Ring gasket materials: EPDM-HT, NBR-HT, Viton, Chloroprene, PTFE*
  • Plate heights up to 3 m
  • Flow rates up to 5,000 m3/h
  • Working pressure up to 30 bar
  • Working temperatures from -20 °C to 180 °C

*other materials available upon request


  • HVAC industry
  • Marine/offshore industry
  • Dairy/food/beverage industry
  • Sugar industry
  • Pulp and paper industry
  • Heavy industry
  • Mining industry
  • Petrochemical industry
  • Chemical industry
  • Evaporation and condensing duties
  • High pressure liquid/liquid applications

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