Spiral heat exchangers have a unique design, two flat plates wound around a central core to form two concentric spiral channels. They excel in fouling and slurry service but their spares requirements are distinct from other heat exchanger types.
AQ Process Systems sources and exports the key maintenance items for spiral heat exchangers, flat cover gaskets (the primary wear item replaced during every cleaning), stud bolts, and cover plates. We also supply spacer studs, centre plugs, nozzle components, and wear-resistant linings.
For heavily fouled spiral HX units requiring frequent cleaning, we recommend maintaining a set of replacement cover gaskets on-site to minimise turnaround time.
| Component | Specification | Description |
|---|---|---|
| Cover Components | ||
| Cover Gaskets (Flat) | Compressed fibre, graphite, or PTFE | Full-face type | Flat gaskets sealing the spiral body to the side covers, replaced every time the covers are removed for cleaning. |
| Cover Plates | CS or SS | Machined flat | Drilled bolt pattern | Flat side cover plates providing access to the spiral channels for inspection and mechanical cleaning. |
| Cover Stud Bolts & Nuts | High-tensile | B7/2H or equivalent | Stud bolts and heavy hex nuts clamping the covers to the spiral body, replaced if stretched or corroded. |
| Spiral Body Components | ||
| Spacer Studs | Welded pins | CS or SS | Maintaining channel gap | Internal spacer studs (pins) welded to the spiral plates to maintain the designed channel spacing. |
| Centre Plug / Core | CS or SS | Central column | Central core plug around which the spiral plates are wound, replacement if corroded or eroded. |
| Wear Plates / Liners | Hardened SS or Stellite overlay | Wear-resistant liners for inlet zones exposed to abrasive slurry flow. |
| Nozzles & Fittings | ||
| Nozzle Connections | Flanged | Tangential or axial entry | Inlet and outlet nozzle assemblies, tangential connections on the spiral body and axial connections on covers. |
| Nozzle Gaskets | Spiral wound or ring joint | Gaskets for nozzle flange connections, spiral wound, ring joint, or kammprofile types. |
| Vent & Drain Fittings | Small-bore | Threaded or socket-weld | Vent and drain connections on covers and spiral body for air removal and drainage. |
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.
The primary spare for spiral heat exchangers is the flat cover gasket, replaced every time the covers are removed for inspection or cleaning. Other spares include cover stud bolts (stretching over repeated tightening cycles), spacer studs (corrosion or erosion in aggressive service), nozzle gaskets, and wear plates for abrasive slurry applications.
Frequency depends on the fouling severity of the process fluid. In clean service, covers may only be opened during scheduled turnarounds (every 1-3 years). In heavy fouling or slurry service, opening may be required every 3-6 months. Each opening requires a new set of cover gaskets.
The spiral plate body itself is very difficult to repair or modify in the field. If the spiral channels develop leaks or significant corrosion, the body typically needs to be replaced. However, nozzles, covers, studs, spacer pins, and wear plates can all be replaced or refurbished. AQ Process Systems can advise on repair vs replacement based on the damage assessment.
Yes. We supply cover gaskets, stud bolts, cover plates, spacer studs, and nozzle gaskets compatible with Alfa Laval spiral heat exchangers. Parts are identified by the unit model and serial number.
The gasket material depends on the process fluid and temperature. Compressed fibre is suitable for general water and hydrocarbon service up to 200°C. Flexible graphite is preferred for high-temperature or steam service. PTFE-faced gaskets are used for corrosive chemical service. We recommend the correct material based on your operating conditions.
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