Common faults of tubular heat exchangers

1. Two media inter-connect (internal leakage):
Causes: Corrosion, perforation and cracking of heat exchange tubes; cracking of expansion joints (weld joints) between heat exchange tubes and tube sheets; leakage of floating head flange seal of floating head heat exchanger.
Treatment method: Replace or block the leaking heat exchange tubes; re-expand (repair weld) or block the heat exchange tubes and tube sheets; tighten bolts or replace sealing gaskets.
2. Leakage of seal at flange:
Causes: Insufficient pressure bearing, corrosion, deterioration of gaskets; insufficient strength of bolts, looseness or corrosion; insufficient rigidity of flanges and defects on sealing surfaces; uneven or misaligned flanges, and poor quality of gaskets.
Treatment method: Tighten bolts and replace gaskets; upgrade bolt material, tighten bolts or replace bolts; replace flanges or deal with defects; re-assemble or replace flanges, and replace gaskets.
3. Poor heat transfer effect:
Causes: Scaling of heat exchange tubes; poor water quality, oil pollution and microorganisms; short circuit of partitions.
Treatment method: chemical cleaning or jet cleaning of scale; strengthen filtration, purification media, and water quality management; replace pipe box gaskets or replace baffles.
4. Resistance drop exceeds the allowable value:
Cause: scaling inside the shell and inside and outside the tube.
Treatment method: use jet or chemical cleaning of scale.
5. Severe vibration:
Cause: resonance caused by medium frequency; resonance caused by external pipeline vibration.
Treatment method: change flow rate or change tube bundle natural frequency; strengthen pipeline and reduce vibration.