Why choose a fully welded PHE over a gasketed one?

When the fluid, pressure, or temperature would exceed what any elastomer gasket can safely handle, or the fluid is chemically incompatible with gasket materials, a fully welded plate pack removes the gasket limitation entirely.

Can a welded plate heat exchanger be opened for cleaning?

No, the welded plate pack cannot be mechanically disassembled. Cleaning is done by CIP (clean-in-place) circulation or chemical flushing, so fluid cleanliness and fouling tendency should be reviewed at the design stage.

What pressure and temperature can a welded PHE handle?

Design dependent, but welded construction typically supports meaningfully higher pressure and temperature than gasketed units, up to around 40 bar and 350 deg C depending on plate material and thickness selected.

What plate materials are available?

SS 316 / SS 316L is standard, with titanium and Hastelloy available for more aggressive or high-temperature corrosive duties.

What information do you need for a quotation?

Fluid types on both sides, flow rates, inlet/outlet temperatures, operating pressure, and any known fouling tendency of the process fluid.

Welded Plate Heat Exchanger

HOME Welded Plate Heat Exchangers Welded Plate Heat Exchanger

Welded Plate Heat Exchanger

SRJ welded plate heat exchangers join every plate by a full perimeter weld, eliminating gaskets from the plate pack entirely for duties involving high pressure, high temperature, or fluids incompatible with elastomer seals.

A welded plate heat exchanger is built by joining every plate in the pack with a continuous perimeter weld instead of elastomer gaskets, producing a plate pack with no gasket material anywhere in the wetted path. Only the frame connections at the inlet and outlet ports may retain a static gasket outside the plate pack itself, depending on design.

Removing gaskets from the plate pack removes the two limitations that gaskets impose: a maximum safe operating temperature and pressure set by the elastomer, and chemical compatibility between the gasket material and the process fluid. A welded plate heat exchanger can therefore run at higher temperatures and pressures than an equivalent gasketed unit, and can handle fluids, such as thermal oils, aggressive solvents, or high-pressure steam, that would degrade or attack any elastomer gasket over time.

The trade-off is serviceability: a fully welded plate pack cannot be mechanically opened for inspection or plate-by-plate cleaning the way a gasketed unit can. Maintenance is carried out by CIP (clean-in-place) circulation, chemical flushing, or in some designs, opening only the frame at fixed intervals for external inspection of the pack. This makes fluid cleanliness and duty selection more important at the design stage than with a serviceable gasketed unit.

Typical duties include high-pressure steam heating, thermal oil circuits, high-temperature process heat recovery, and cooling or heating of fluids that are simply not compatible with any standard gasket material, including many solvents and aggressive chemical process streams.

SRJ manufactures welded plate heat exchangers using the same in-house pressing tooling as our gasketed range, so plate corrugation and thermal performance are consistent with our standard model line. Every weld is inspected and the completed unit is pressure tested before dispatch, with mill test certificates available on request for the plate material used.

Technical Specifications

Parameter	Range / Options
Plate Materials	SS 316 / SS 316L / Titanium / Hastelloy
Plate Thickness	0.4 mm - 0.8 mm
Construction	Fully welded plate pack, no gaskets in the wetted path
Max Design Pressure	Up to 40 bar (design dependent)
Max Temperature	Up to 350 deg C
Connection Sizes	DN25 to DN300
Frame Options	MS powder-coated / SS-clad frames
Cleaning Method	CIP (clean-in-place) / chemical circulation

Where This Is Used

High-Pressure Steam Heating

Steam-to-liquid heating duties beyond the safe operating range of gasketed plate packs.

Thermal Oil Systems

Heat transfer with thermal oils at high temperature where no elastomer gasket would survive long-term.

Aggressive Chemical Processing

Solvents and process chemicals that attack standard gasket materials, handled gasket-free.

High-Temperature Heat Recovery

Waste heat recovery from high-temperature process streams in power and process plants.

Petrochemical & Refining

High pressure and high temperature duty cycles typical of refinery and petrochemical process units.

Frequently Asked Questions

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