Semi-welded plate heat exchanger for industrial refrigeration ammonia applications | Sondex/Danfoss | Philippopoulos s.a.
Semi-welded plate heat exchanger for industrial refrigeration ammonia applications | Sondex/Danfoss | Philippopoulos s.a.

Semi-welded plate heat exchanger for industrial refrigeration ammonia applications | Sondex/Danfoss

Semi-Welded Plate Heat Exchangers Danfoss SONDEX for NH₃

Semi-welded plate heat exchangers are utilized in industrial refrigeration with ammonia, where refrigerant charge limitation, controlled pressure drop, and maintenance of the plate pack are required. The SW19–SW59 series supports operation from -40°C to 150°C and pressure up to 40 bar, depending on configuration.

Construction and Sealing

The refrigerant side is configured with laser-welded plate pairs into cassettes. The secondary side remains gasketed, allowing for opening, cleaning, and replacement of gaskets or cassettes. The double-gasket system directs potential leaks outside the plate pack, reducing cross-contamination risk between circuits.

Media and Operating Conditions

Suitable media:

  • NH₃, R134a, R1234ze, R513A, R410A, R507A
  • water, ethylene glycol, propylene glycol, and brine mixtures
  • ammonia applications in condensation, evaporation, subcooling, heat recovery, and oil cooling

Typical selection parameters: DN65–DN200, PN16/25/40 or ANSI Class 150/300, plate materials AISI 304 or AISI 316, thickness 0.5–0.7 mm, and gaskets NBR HT, HNBR, EPDM, Chloroprene, or FEPM, depending on the medium.

Standards and Testing

Construction can be based on CE/PED, EN 13445, and ASME VIII Sec. 1. Includes strength tests, 48-hour vacuum tests, pressure fatigue cycles, and helium leak testing on cassettes and assembled exchangers.

Comparison with Fully Welded Plate Exchanger

In NH₃ applications, the semi-welded design limits gasket exposure to the refrigerant. Compared to fully welded exchangers, it provides access for mechanical cleaning and cassette replacement.

FAQ

Where is it used? In flooded/pumped evaporators, condensers, subcoolers, economizers, desuperheaters, and oil coolers.
What affects selection? Thermal load, flow rates, ΔT, allowable pressure drop, refrigerant type, glycol concentration, and maintenance schedule.

Datasheet and documents

Description

Meet application needs with maximum performance

Our semi-welded plate heat exchangers are optimized for industrial applications and include extensive improvements in professional refrigeration. The semi-welded plate heat exchangers from Danfoss is designed for natural refrigerant applications and can be used for applications such as Condensers, flooded and pumped evaporators, Sub-coolers, Desuperheaters, Superheaters, Economizers and Oil coolers. The product range includes the sizes SW19-SW59, with more to come, and can handle temperatures ranging from -40°C up to 150°C (-40°F up to 302°F) and pressure ranges up to 40 bar (300 psi).

Features and benefits

  • Excellent heat transfer capabilities
  • Reliable design - operational safety
  • Easy product configuration
  • Comprehensive testing
  • Part of diversified product range for IR systems
  • Comprehensive HE2 leak testing
  • Optimization of overall system design
  • Danfoss system control experts

High quality product - fully tested

The Danfoss semi-welded plate heat exchanger design has been verified through thermal and mechanical tests. Furthermore, each semi-welded plate cassette and fully assembled plate heat exchanger are thoroughly leak tested with helium before they leave the Danfoss factory.

New plate design delivers excellent heat transfer capabilities

The SW19-59 range features excellent heat transfer capabilities via improved thermal performance due to optimized plate geometry supporting high turbulent natural refrigerant flow enabling a compact design and supporting lower charge for your refrigeration.

New gasket system improves plate pack stability and safety

The new gasket system ensures high gasket stability and optimal plate alignment due to new gasket and gasket grove design, enabling easy and fast service and maintenance. The new design improves the sealing effect and prevents gasket-blow out. Furthermore, the risk of contamination is reduced due to the double gasket barrier that will drain potential leakages outside of the plate pack. The new gasket system is glue free for easy maintenance.

Easy maintenance and service

The new range is easy to service and maintain. Easy access to the plate pack with the non-corrosive nylon roller that makes it easy to slide the follower along the carrying bar. Assembly of the plate heat exchanger is fast and safe thanks to fixed bolt heads and lock bushes which prevent the nut and bolt head from rotating when opening and closing the unit. The enhanced gasket system ensures easy and precise plate pack alignment.

Availability

Our line of Semi-welded plate heat exchangers is available now around the world from our factories in the USA, China, and Europe. Reach out to your local representative.