GPLKS

Common issues

• Internal plate leakage from thermal fatigue cracking after years of cycling
• Fouling/scaling on the water side reducing heat transfer, seen as rising approach temperature
• Leak-detection port on the double-wall safety channel weeping, indicating a breached plate
• Brazed joint corrosion at connections where dissimilar metals or poor water treatment is present
• Reduced flow from partial blockage, since a brazed plate pack cannot be mechanically opened for cleaning
• Copper braze attack from aggressive or high-chloride cooling water

Inspection checklist

• Check pressure drop and approach temperature against the commissioning baseline to detect fouling
• Inspect the leak-detection/drainage port on the safety channel for any trace of fluid
• Verify insulation and connections are free of external corrosion or weeping
• Confirm operating pressure and temperature remain within the plate rating
• Review water treatment/dosing records for the cooling circuit
• Chemically clean (CIP), rather than mechanically open, per manufacturer instructions if fouling is suspected

Service intervals

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

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• Complete replacement unit (brazed plate packs are not field-repairable or re-brazable)
• Gaskets/seals for connection flanges (not the internal brazed joints)
• Pressure and temperature sensors/gauges fitted to the unit
• Isolation valves and strainer elements on the connecting pipework

Safety

• The double-wall design exists specifically to stop the two media mixing if one plate pack leaks - never bypass or blank the drainage/detection port
• Unit can be hot and under pressure; isolate and depressurise both circuits before any connection work
• Do not attempt to mechanically open a brazed plate pack - it is not designed to be disassembled

Class survey

Class treats the leak-detection/drain port on double-wall safety heat exchangers as the key survey item - surveyors expect it logged as checked and dry at each round, since it is the main external evidence that the internal barrier between the two media is intact.

Estimated lifetime: No fixed running-hours limit for a brazed unit; service life is governed by fouling/corrosion trend rather than hours, and commonly exceeds 15-20 years in a closed circuit with good water treatment - open or raw-water circuits with poor treatment can fail much sooner.