SINCE 1981
21
SYMPTOM: A fluid is leaking from where the external piping is connected to the heat exchan
-
ger.
CAUSE: Either the gasket sealing the flange to the frame has become loose or damaged or in
some cases the alloy nozzle liner or stub end has been damaged due to corrosion or excessive
loading.
SOLUTION: Shut down the heat exchanger. Drain and remove the piping from the leaking
connection. After the piping is removed, if the connection sealing gasket is out of place or da-
maged carefully replace the gasket. Clean the gasket sealing surface to make certain there is
no foreign debris that could cause damage to the gasket or leaks. Reconnect the piping. When
the piping is removed, you should also examine the alloy nozzle liner or stub end for any sign
of cracks or damage that could cause a leak. If damage is suspected, take the unit apart in
accordance with section 5.1. Visually or dye penetrant the liner or stub end for cracks or
leaks. The damaged connections should be either repaired or replaced. Close up the heat
exchanger in accordance with section 5.2.
SYMPTOM: The pressure drop across the heat exchanger is higher than anticipated.
CAUSE: The heat transfer plates may have become plugged with debris or scaling or the
plates
may be installed incorrectly. Exchanger may have the incorrect plate pattern(s) installed.
SOLUTION: The pressure drop across the heat exchanger must be accurately measured. Ob-
serve the outer edge of plates and confirm they form a honeycomb pattern which indicates
they are installed in the correct position.
If available, backflushing the heat exchanger at a high velocity in the reverse direction may
dislodge trapped debris. If this is not available or successful, the unit must be disassembled
and cleaned.
When disassembled the heat transfer plate pattern can be verified with the plate arrangement
drawings.
SYMPTOM: The heat transfer rate of the heat exchanger declines.
CAUSE: The heat transfer plates have become fouled during operation.
SOLUTION: Follow procedures for cleaning the heat exchanger.
PLATE AND FrAME - HEAT ExCHANgErS