Welded plate heat exchangers handle higher temperatures and more aggressive fluids than gasketed PHEs, but they still require maintenance, particularly the gaskets on the non-welded side (in semi-welded designs) and the frame sealing components. Fully welded block-type units need gaskets, bellows, and nozzle components.
AQ Process Systems sources and exports replacement plate cassettes, gaskets, expansion bellows, and frame parts for semi-welded and fully welded plate exchangers from Alfa Laval, GEA, Kelvion, and other manufacturers.
For fully welded units where the plate pack is not field-serviceable, we supply the peripheral components, frame gaskets, expansion joints, nozzle connections, and instrumentation fittings.
| Component | Specification | Description |
|---|---|---|
| Plates & Cassettes | ||
| Welded Plate Cassettes | SS 316, Ti, Hastelloy | Factory-welded pairs | Pre-welded plate pairs (cassettes) for semi-welded PHEs, welded on one fluid side, gasketed on the other. |
| Replacement Plate Packs | Fully welded block assemblies | Complete welded plate blocks for Compabloc-type exchangers, factory-assembled and pressure-tested. |
| Single Plates | Pressed plates for semi-welded units | Individual replacement plates for semi-welded exchangers where only specific cassettes need renewal. |
| Gaskets & Seals | ||
| Channel Gaskets (Gasketed Side) | EPDM, FKM, HNBR | Semi-welded models | Gaskets for the non-welded fluid side of semi-welded PHEs, the primary maintenance item. |
| Frame Gaskets | Compression seals | Perimeter | Frame-to-plate-pack perimeter gaskets for both semi-welded and fully welded designs. |
| Nozzle Gaskets | Spiral wound or O-ring | Port connections | Gaskets at inlet/outlet nozzle interfaces, spiral wound, O-ring, or flat depending on the design. |
| Structural & Expansion | ||
| Expansion Bellows | SS bellows | Single or multi-ply | Thermal expansion joints on fully welded block units, accommodating differential growth between plate pack and frame. |
| Frame Bolts & Studs | High-tensile | Full-length or stud type | Clamping hardware for compressing the plate pack, studs, nuts, and washers. |
| Nozzle Connections | Flanged or welded | CS or SS | Replacement inlet/outlet nozzle assemblies including companion flanges and weld-neck connections. |
| Support Structures | CS fabricated | Saddles or legs | Frame supports, saddle mounts, and foundation hardware for floor or structure mounting. |
Parts are matched to OEM material specifications and dimensional tolerances. Please provide the equipment manufacturer, model number, and serial number (if available) for precise part identification. Mill Test Certificates (MTC) supplied with all tube materials per EN 10204 3.1.
Semi-welded PHEs need gaskets for the non-welded fluid side (the main maintenance item), plus frame gaskets and bolts. Fully welded block units (like Compabloc) need frame gaskets, expansion bellows, nozzle gaskets, and occasionally complete replacement plate packs when the welded block reaches end of life.
Yes. We supply channel-side gaskets for the gasketed (non-welded) fluid side of semi-welded PHEs from Alfa Laval, GEA, and other manufacturers. These are the primary wear items and are replaced in the same way as standard gasketed PHE gaskets.
Semi-welded PHEs have one welded side and one gasketed side, spares include gaskets, plates, and cassettes, and the unit can be opened for maintenance. Fully welded units (Compabloc, block-type) have no plate-side gaskets, they can only be chemically cleaned, and spares are limited to frame gaskets, bellows, and nozzle connections. The plate pack itself is replaced as a complete unit when it reaches end of life.
Yes. For Alfa Laval Compabloc and similar fully welded plate exchangers, we supply frame gaskets, expansion bellows, nozzle flange gaskets, and structural components. For end-of-life plate packs, we can source replacement welded blocks to OEM specifications.
For semi-welded units, the gasketed-side gaskets have similar lifespans to standard PHE gaskets, typically 3-8 years depending on fluid, temperature, and cycling. Frame gaskets on fully welded units may last 10+ years as they are not exposed to process fluids directly. Expansion bellows lifespan depends on thermal cycling frequency.
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