AXP27-MAX

Common issues

• Fouling/scaling on the seawater side reducing heat transfer efficiency
• Marine growth/biofouling in the seawater circuit
• Erosion-corrosion at high-velocity inlet areas on the seawater side
• Reduced flow from partial blockage, since the fusion-bonded plate pack cannot be mechanically opened for cleaning
• External flange/connection leakage at pipe interfaces
• Freshwater/glycol chemistry degradation affecting corrosion protection on the fresh water side

Inspection checklist

• Monitor approach temperature and pressure drop trend on both circuits against the commissioning baseline
• Inspect strainers/filters upstream on the seawater side
• Check external flange connections and gaskets for leakage
• Review seawater treatment/anti-fouling dosing operation, where fitted
• Check freshwater circuit chemistry/inhibitor concentration
• Inspect support/mounting structure for vibration wear
• Verify pressure relief/safety devices on the circuit are functional and within test date
• Check insulation condition where fitted

Service intervals

Typical intervals for this design class, not the manufacturer’s figures for your model. The manufacturer’s manual is binding.

Critical spares

• Complete replacement unit or plate pack cartridge - fusion-bonded packs are not field-rebuildable like gasketed units; confirm the specific service concept with Alfa Laval
• External flange gaskets/O-rings
• Strainer elements
• CIP cleaning chemicals
• Pressure relief valve, where fitted to protect the 48 bar rated circuit

Safety

• High design pressure (48 bar) - strict isolation/depressurization procedure required before any work on connections
• Pressure testing hazards
• Chemical handling during CIP cleaning
• Ammonia handling precautions apply if the unit serves an ammonia-adjacent circuit

Class survey

Central coolers serving essential systems are surveyed as part of Continuous Machinery Survey. Surveyors check pressure test/relief valve certification given the 48 bar design pressure, external condition, absence of leakage, and that the installation matches the approved cooling system diagram, including the duty/standby arrangement if fitted.

Estimated lifetime: All-stainless fusion-bonded coolers of this type are generally designed for a long service life, often quoted in decades, given their corrosion-resistant construction - provided water chemistry is controlled and the unit stays within its design pressure/temperature envelope. Confirm against Alfa Laval's documentation for the AXP27-MAX.