Standard PHE Operating Procedures
Standard operating principles are critical for preventing damage to the unit:
1. In steam applications, never leave the steam on with the liquid side turned off. Turn the steam off first and on last.
2. Water hammer, if suspected, must be diagnosed and eliminated, or damage may result.
3. Pumps should always be started against closed valves.
4. Valves must be set to open and close gradually. Sudden opening and closing of the valves will subject the exchanger to mechanical and thermal shock and may cause material fatigue.
5. Starting up and shutting down should be managed to minimize differential expansion. Follow the stated start-up and shut-down steps in order.

Analyzing And Troubleshooting PHE Performance

Heat exchanger problems are not always accompanied by obvious symptoms such as leaks or channel intermixing. Some problems are minor but progressive, causing higher energy consumption and performance variability.
Process data around the heat exchanger is invaluable in analyzing and troubleshooting performance. Pressure, flow rate and temperature data from side 1 (usually the process channel) and side 2 (usually the cooling or heating media channel) inlets and outlets can indicate problems with either stream. This instrumentation is well worth the cost of installation for exchangers critical to process control and efficiency. They can signal operators when the process is about to become uncontrollable.