If the outlet temperature frequently deviates from the set value and the regulating valve operates noticeably more often during operation, it is usually not an instrument problem but a deviation between heat exchange capacity and current operating conditions. Procurement personnel can use such phenomena as a starting point for checking equipment status during acceptance and subsequent use.
During troubleshooting, prioritize checking heat load, medium flow rate, inlet and outlet temperatures, and allowable pressure drop to see whether they match the design conditions used for model selection. If any of the four data items deviates significantly, it will manifest as frequent temperature regulation. If the medium flow fluctuation range exceeds ±15%, it should be separately stated in the procurement technical agreement so that the supplier can calculate the flow velocity distribution in the shell side and tube side, avoiding repeated adjustments after commissioning.
The connection between the tube bundle and the tubesheet is where leakage and thermal stress concentrate. During operation, the fluctuation range of medium temperature and pressure should be controlled to reduce the repeated effect of alternating loads on the connection; during shutdown inspection, focus on observing whether there are signs of leakage, scale accumulation, or sealing surface damage at this location. If abnormalities are found, it is advisable to record the operating conditions and contact the supplier to confirm the handling method.
The cleaning cycle should be arranged according to water quality conditions and should not be generalized based on a fixed calendar period. In cases with high water hardness or high suspended solids, the inspection interval can be shortened; first observe pressure drop and heat transfer changes, then decide whether cleaning is needed to avoid ineffective disassembly and reassembly.
When signing the technical agreement, procurement personnel should specify the medium flow fluctuation range, allowable pressure drop, and water quality conditions, and require the supplier to provide operation and maintenance instructions to provide a basis for subsequent inspection and cleaning arrangements.
