All fired and electric immersion type heaters are capable of exceeding the maximum recommended film temperature of the heat transfer fluid under certain condition. Exceeding the maximum film temperature for a period of time can cause excessive cracking and premature fluid failure. Maintain Design Fluid Velocity at all Times through the Heater - Pressure drop across the entire system should be calculated when sizing pumps. System by-pass valve response should be tuned to maintain design fluid flow rate under all process conditions. Filters and strainers should be properly located and monitored to prevent blinding.
Cold fluid can overheat if heater operates at full power from start-up.
Make sure this procedure doesn t heat up system more rapidly than manufactures recommendations. Check the Combustion Chamber - Improper flame propagation or burner alignment can cause hot spots on tubes. In many cases, fouling or corrosion of the expansion tank are the first signs that a problem exists if routine fluid analyses have not been performed. Never continuously operate a system with the warm up valve open. On a vented systems, the tank itself and lines leading to it should be left uninsulated.