PHE Technologies Compared
Gasketed, brazed, semi-welded, fully welded, shell & plate, or welded block: each construction solves a different engineering problem. This guide compares the seven technologies ARES PHE manufactures, so you can match the right construction to your pressure, temperature, media, and maintenance requirements before requesting a selection.
The Serviceability Spectrum
The most fundamental choice in PHE selection is the trade-off between service access and containment. At one end, gasketed units open completely for cleaning, inspection, and capacity changes. At the other, brazed units are permanently sealed: maintenance-free, but not serviceable. Every technology in between trades access for higher pressure, temperature, or chemical resistance.
Side-by-Side Comparison
Figures reflect standard ARES PHE series ratings. Higher ratings are available on request for specific duties.
| Criteria | Gasketed | Semi-Welded | Fully Welded | Welded Block | Shell & Plate | Brazed | Spiral |
|---|---|---|---|---|---|---|---|
| ARES PHE Series | A AP AWG ADP AFP AH | ASW | AFW | AWB | ASP | ABR | Spiral |
| Max Design Pressure | 25 bar | 30 bar | 40 bar | 60 bar | 100 bar | 45 bar | 30 bar |
| Temperature Range | -30 to +180°C | -40 to +200°C | -40 to +350°C | -50 to +400°C | -60 to +450°C | -196 to +200°C | -40 to +800°C |
| Gaskets | Both sides | One side only | None | None | None | None | Cover gasket, or none if welded |
| Service Access | Full: openable, expandable, plates replaceable | Gasketed utility side opens fully | Openable one or both sides for mechanical cleaning | Four removable panels; cleaning on all flow edges | Plate pack removable from shell | Sealed; no routine maintenance | Covers remove for direct channel access |
| Best-Suited Media | Water, glycols, oils, food and hygienic fluids | Refrigerants and ammonia; aggressive fluid on welded side | Aggressive chemicals and solvents attacking elastomers | Severe fouling process duties; hydroblasting access | High-pressure steam, gases, condensing duties | Clean closed circuits: HVAC water, refrigerants, oil | Sludges, slurries, fibrous and viscous fluids |
| Typical Applications | HVAC, marine, district energy, food and dairy, general industry | Industrial refrigeration, heat pumps, chillers | Chemical and petrochemical processing | Refineries, petrochemical, heavy industry | Power generation, oil & gas, steam systems | Rooftop units, heat pumps, skid packages, oil cooling | Wastewater, fermentation, pulp and paper, process liquids |
| Cost Logic | Lowest lifecycle cost where media allow; gasket renewal every 3-7 years | Premium over gasketed; gaskets remain only on the benign side | Higher initial cost; 15-20+ year service life in aggressive duty | Engineered severe-duty investment | Alternative to shell & tube at a fraction of the footprint | Lowest initial cost; replaced, not repaired, at end of life | Selected where channel geometry, not plate area, solves the duty |
Each Technology in Brief
Gasketed
The workhorse of heat transfer. Elastomer-gasketed plates in a bolted frame, fully openable for cleaning and expandable in capacity by adding plates.
Strengths
- Full service and inspection access
- Capacity can grow with your plant
- Widest plate and gasket material choice
Consider
- Gasket compatibility limits media
- Pressure and temperature ceiling
Semi-Welded
Plate pairs laser-welded into cassettes on the process side, with conventional gaskets on the utility side. The aggressive fluid contacts only the porthole ring gaskets.
Strengths
- Handles ammonia and refrigerants
- Utility side keeps full service access
- Only one gasket loop remains in service
Consider
- Welded side not mechanically cleanable
- Premium over standard gasketed
Fully Welded
A completely laser-welded plate pack with no gaskets anywhere in the flow path. Chemical resistance is defined by plate metallurgy alone.
Strengths
- No elastomer to attack or age
- 40 bar and 350°C standard rating
- Openable for mechanical cleaning
Consider
- Capacity fixed at manufacture
- Higher initial investment
Welded Block
A gasket-free cube of laser-welded plates enclosed by four bolted side panels, one per flow edge, each removable for hydroblasting and inspection.
Strengths
- 60 bar and 400°C capability
- Mechanical cleaning on all four flow edges
- Built for severe fouling duties
Consider
- Heaviest construction in the range
- Engineered per duty, longer lead time
Shell & Plate
A circular welded plate pack inside a cylindrical pressure shell: plate-exchanger efficiency with pressure-vessel containment, up to 100 bar and 450°C.
Strengths
- Highest pressure rating in the range (up to 100 bar)
- Plate pack removable for inspection
- Fraction of shell & tube footprint
Consider
- Shell side geometry fixed
- Specialist duty selection required
Brazed
Stainless plates permanently joined with copper or nickel brazing. No gaskets, no bolts, no frame: a compact sealed unit that is effectively maintenance-free.
Strengths
- 50-80% smaller and lighter than gasketed
- No routine maintenance
- Lowest initial cost per duty
Consider
- Not serviceable or cleanable internally
- Copper braze limits some media (nickel braze available)
Spiral
Two plates wound around a central core, giving each stream one continuous curved passage rather than many parallel channels.
Strengths
- Handles sludges, slurries and fibres
- No dead zones for solids to settle
- Up to 800°C when fully welded
Consider
- Lower pressure ceiling than fully welded, welded block, and shell & plate types
- Larger footprint per unit of area
A Practical Selection Path
Start with the media. If both fluids are compatible with elastomer gaskets, a gasketed series is almost always the most economical choice over the unit's life, and, with semi-welded, one of only two types that let capacity grow later. If exactly one fluid attacks gaskets, semi-welded solves the problem at the lowest premium.
If no gasket can survive the duty, the choice between fully welded, welded block, and shell & plate comes down to pressure and fouling. Below 40 bar with moderate fouling, fully welded offers the best balance. Severe fouling that demands hydroblasting access points to the welded block. Pressures beyond 60 bar, steam, or gas duties belong to shell & plate.
And for clean, closed circuits where nobody will ever open the unit, brazed delivers the duty in the smallest, most economical package. Separately from all of these, if the fluid carries solids or fibres that would block a plate pack at all, the answer is a spiral rather than any plate type (for moderate fibre or particle loads, consider AWG Free Flow first). Our selection software sizes all six plate technologies against your actual duty conditions, or our engineers will recommend the right construction from your datasheet.
Not Sure Which Technology Fits Your Duty?
Run your conditions through the ARES PHE selection software, or send us your duty specification and our engineers will recommend the right construction.