Alfa Laval
Semi-Welded Plate Heat Exchanger
The Alfa Laval semi-welded plate heat exchanger is built from thin corrugated twin plates laser-welded into cassettes on one side and sealed by gaskets on the other. This hybrid construction handles media that gaskets alone cannot, and withstands higher design pressures than a fully gasketed unit, while remaining serviceable.
Product Benefits
- Made for tough refrigerants: Refrigerants such as ammonia and carbon dioxide are hard on conventional gasketed exchangers, both chemically and in terms of pressure.
- Refrigerant on the welded side: The semi-welded design routes the refrigerant through the laser-welded side of each cassette, where only small ring gaskets are exposed.
- Best of both constructions: The secondary fluid runs on the conventionally gasketed side, combining welded robustness with gasketed flexibility.
- Reftight sealing system: The Reftight™ system of combined ring and field gaskets is central to this reliability.
- Still opens for service: Because the plate pack opens like a gasketed unit, inspection, cleaning and capacity changes remain straightforward.
Where It's Used
- Industrial refrigeration: The exchanger is designed mainly for industrial refrigeration and heat pump systems.
- Natural refrigerants: It suits systems running ammonia and carbon dioxide as working fluids.
- Evaporators and condensers: Typical duties include flooded and DX evaporators, liquid-cooled condensers and cascade systems.
- Gas coolers and oil coolers: It also serves as desuperheater and gas cooler, economizer and subcooler, and oil cooler.
Good to Know
- Plates and plate types: Plates come in several stainless steel grades or titanium, and a range of plate types covers different sizes and duties.
- Gasket compounds: Ring and field gaskets are offered in multiple elastomer compounds to match the refrigerant and temperature.
- PED-approved data: All technical data is given for PED-approved versions.
- Specify from the system: The choice of plate type, plate material and gasket compounds follows from the refrigerant, the temperatures and the pressures in your system.
- Refurbish in place: Ring gaskets and field gaskets are replaceable, so the unit can be refurbished on site over a long service life.
