In the past, no satisfying solution was available for using gasketed plate heat exchangers for special process conditions or aggressive media. The limitation was always the gasket material.
Semi-welded units overcome this limitation! These are as flexible as gasketed heat exchangers while enhancing the application range for PHEs for use with aggressive liquids and gases, such as ammonia or aggressive process chemicals where suitable elastomers are not available to act as a sealant between the plates. In the case of ammonia refrigeration, the reduced hold-up volume results in significant additional savings.
This type of heat exchanger uses a unique approach: alternating channels are laser welded. Aggressive media (for example Ammonia) flows in the welded channels. Non-aggressive media (like brine or water) passes through the gasketed channels. Despite partial welded construction, the unit can easily be disassembled to replace gaskets or to take care of other maintenance.
Like all VARALKA products, they are also highly efficient, reliable, and easy to operate and maintain.
Applications of Semi-Welded PHEs
- Ammonia Evaporators – Gravitation, DX or Flooded
- Ammonia Condensers
- Cascade Heat Exchangers (NH3, CO2)
- Ammonia De-superheaters, Economisers
- Oil Coolers
- Sulphuric Acid Coolers
|Connections Sizes||DN25 to DN250|
|Working Pressure||< 63 Bar|
|Working Temperature||180 deg C|
|Plate Materials||SS304 / SS316L, Titanium Gr 1 / 11, Hastelloy C-276|
|Gasket Materials||CR, EPDM, NBR, HNBR FKM, PTFE Encapsulated|
|Frame Materials||IS2062, SA516 Gr 60/70, SS304, SS304 Cladded|
|Tie-Rods, Fasteners||IS1367, SA193/SA194, ASTM A193/194|
|Construction Codes||Standard Engineering Practice, ASME Sec VIII Div 1, PED, U Stamp(*)|