High pressure and temperature resistance thanks to the absence of elastomer gaskets - the first choice in oil and gas as well as chemical and pharmaceutical processes, where hydrocarbons, acids, solvents, steam and thermal oil would attack any gasket.
Low-maintenance, as there are no gaskets to age. Not disassemblable; cleaning is chemical (CIP).
Design and limits
Plates are welded in pairs and the pack is closed without gaskets. This removes the elastomer gasket as the limit for pressure, temperature and media - in exchange the pack cannot be opened and is cleaned chemically.
| Max. operating pressure | 35 bar |
|---|---|
| Temperature range | -50 to 300 °C |
| Plate materials | 1.4301 (304), 1.4404 (316L) |
| Gaskets | gasket-free |
Preliminary guide values. You will receive the binding sizing with your individual quote.
Strengths
- high pressure and temperature capability
- no gasket replacement, no gasket ageing
- resistant to aggressive and creeping media
Limits
- cannot be opened mechanically, chemical cleaning only
- plate count cannot be changed later
Pressure ratings and temperature limits
Fully welded plate heat exchangers reach substantially higher operating pressures and temperatures than gasketed units. This is possible because there are no elastomer gaskets: the limits are set solely by plate material, weld seam and frame construction.
Low temperatures are equally uncritical, for instance in refrigeration plants with evaporating temperatures far below zero degrees Celsius. As with any pressure equipment, classification under the Pressure Equipment Directive 2014/68/EU depends on maximum allowable pressure, volume and fluid group.
The main limitation is thermal cycling: fast, frequent temperature swings stress the weld seams. For cyclic processes, load profile and operating mode therefore belong in the thermal design.
Like gasketed units, welded exchangers are tested at pressures above the design pressure. For plants with pressure surges - for instance from fast-switching valves or cycling compressors - the real pressure profile belongs in the design: short peaks stress weld seams more than a constantly high operating pressure.
Materials and joining technology
The plates are made of stainless steel 1.4301 (304) or 1.4404 (316L) and are laser or TIG welded into a permanently sealed pack. Connections are designed as flanges or welded nozzles and integrated directly into the frame.
Since the construction can be executed entirely copper-free, welded units are also suitable for ammonia (NH3) - unlike copper-brazed heat exchangers. For seawater and chloride-rich process media, the gasketed design with titanium plates is available.
With no ageing gaskets, the classic wear point of gasketed units disappears. In return, the pack cannot be disassembled: cleaning is chemical (CIP), so the fouling tendency of the media should be considered during selection.
Typical applications
The main domain is oil and gas: heat recovery from process streams, cooling of compressors and hydraulic circuits, conditioning of condensates. Hydrocarbons make elastomer gaskets swell - without a gasket, that wear part is gone.
The second large field is chemical and pharmaceutical processing: reactor tempering, condensation of solvent vapours and heat recovery with steam or thermal oil as the heat transfer medium. Acids, alkalis and solvents move the resistance limit from the elastomer to the plate material, and steam and thermal oil exceed the temperature limit of any gasket anyway.
Where regular mechanical cleaning or subsequent capacity adjustment is required, however, the gasketed plate heat exchanger remains the more flexible choice - the decision follows medium, pressure, temperature and maintenance concept.
Selection and sizing in practice
For selecting a welded plate heat exchanger, what counts besides heat duty and temperatures are above all operating and design pressure, the temperature profile of the operating mode and the medium with its concentrations and fouling tendency. From these follow plate material, connection type and the structural design of the pack.
Since the pack cannot be opened, the fouling question belongs at the start: particle-laden or encrusting media require filtration upstream of the unit or CIP-capable piping with flushing connections. Properly planned, the maintenance effort stays minimal for years.
For refrigerant and steam applications, safeguarding counts: safety valves, expansion volumes and integration into the plant control system are part of the planning. Sizing for the real operating range - not just the extreme point - avoids unnecessarily heavy and expensive designs.
The Platecore configurator captures these key figures online and checks them for plausibility right away. The thermal design itself is done by our engineering team - the binding quote follows within one business day.