Alfa Laval AQ14 Series
Alfa Laval Alfa Laval AQ14 Series — Alfa Laval Gasketed Plate Heat Exchangers (GPHE). Alfa Laval Gasketed Plate Heat Exchangers (GPHE) are compact, efficiency-optimized heat exchangers used in marine engineering and industry for heating, cooling and heat recovery. They consist of pressed, corrugated plates with gaskets arranged in a frame. The herringbone-pattern plates gener
Inspector Detail
▸
Common issues
- Gasket leakage from compression set/hardening after repeated thermal cycling
- Plate pitting or cracking, often starting near the inlet/outlet ports where flow velocity is highest
- Fouling or partial blockage from scaling, biological growth or process-side debris
- Internal cross-leakage between the two media, most often traced to a damaged or misfitted gasket
- Cavitation noise and vibration at excessive flow rates for the plate pattern
- External corrosion of the frame plate, tightening bolts and carrying/guide bars
- Uneven or under/over-tightening of the plate pack causing leaks or plate distortion
Inspection checklist
- Pressure/leak test after any reassembly, both sides
- Visual check of every gasket for cracking, hardening, or misalignment in the groove
- Measure the compressed plate pack (tightening) dimension against the value stamped on the frame
- Inspect plate surfaces for pitting, erosion or discolouration, especially near ports
- Check the drain/vent ports between the two media for signs of cross-leakage
- Verify tie bolts are torqued evenly in the correct sequence
- Check frame plate, carrying bar and guide bar for corrosion or damage
- Compare actual approach/outlet temperatures against design duty
- Inspect connection flanges and their gaskets for leakage or damage
Service intervals
| Gasket replacement | typically every 3-5 years, sooner if leakage or hardening is found - duty dependent |
| Plate pack opening for internal inspection | annually, or per the vessel's planned maintenance system |
| External cleaning of frame and connections | as needed, based on observed fouling trend |
| Tightening (compressed) dimension check | at every opening and re-assembly |
Typical wear limits
| Plate pitting/erosion depth | no single figure applies across duties - reject any plate showing through-wall pitting, cracking, or visible thinning at the ports; use the manufacturer's plate-specific rejection criteria |
| Compressed (tightening) plate pack dimension | must stay within the tolerance band stamped on the frame plate for the actual plate count - confirm the stamped value before re-tightening after any plate change |
| Gasket groove/compression set | renew when the gasket no longer springs back to its free height, or per the manufacturer's gasket-specific compression chart |
Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.
Critical spares
- Full gasket set matched to the fluid service (e.g. NBR or EPDM) and plate pattern
- Spare plate set for replacing damaged or heavily pitted plates
- Tie bolts, nuts and washers
- Connection flange gaskets and studs
- Carrying bar / guide bar bushings
Safety
- Pressurised system - fully isolate and depressurise before opening the plate pack
- Hot surfaces where the unit is on a heating/thermal oil duty
- Crush hazard from the tightening bolts and heavy end frame when assembling/disassembling
- Possible exposure to process fluids (fuel, lube oil, chemicals) when opening - use appropriate PPE
Class survey
Plate heat exchangers on essential cooling or heating duties are commonly included in a Continuous Survey Machinery programme; surveyors typically expect gasket renewal records, a leak/pressure test after re-assembly, and evidence that the tightening dimension has been checked against the frame stamping.
Components & Design
Component data being added…
Technical Data
🤖 Ask about this model
One free question — answered like a marine engineer. No account needed.
Common failures & inspection points
Inspect seals visually for cracks, hardening, swelling and discoloration; verify material compatibility with process fluids; check ClipGrip™ fastening. Aging symptoms and loss of elasticity are replacement indicators.
Verify A-dimension per manufacturer specifications with caliper (metallic contact required). Keep bolts clean and lubricated. Avoid over-tightening. Perform regular re-tightening after operating hours. At too low A-dimension, pressure loss and leakage are to be expected.
Monitor pressure differential across heat exchanger (increase indicates deposits). Check heat duty versus design value. Optimize CIP intervals after performance audits. Deposits generate higher pump load (energy waste up to 8,000 kWh/year possible).
After disassembly, inspect plate surfaces for local measurements (pitting), cracks and perforation corrosion. Verify material compatibility with process fluid. Observe fatigue cracks especially at corners and transitions. When perforation occurs, plate is unrecoverable and must be replaced.
After disassembly and cleaning, perform hydrostatic test per data sheet. Test pressure typically 1.5× operating pressure. Check external and internal leakage at all connections and plate edges. Document findings.
After opening, verify plate sequence and honeycomb pattern (corrected chevron patterns must alternate). Activate/validate 5-point alignment system for larger units. Offset or misplacement leads to short-circuiting and reduced heat duty.
Type-general inspection and maintenance points for this equipment category — not model-specific.
Suppliers & Spare Parts
Direct links to manufacturer, datasheet, spare-parts portal and dealers — request access below.
📄 Request sourcing links & documentsCases, daily reports, timesheets and AI troubleshooting in the OceanSphere Marine app — free for 14 days.
Start free trial →Find manufacturers, repair shops and spare-part dealers in the Maritime Network — our global company directory.
Maritime Network →