Piping systems, heat tracing

Fuel handling system. The transfer piping is heat traced to maintain the fuel at the elevated temperature to reduce pumping costs. Further, fuel recirculation lines are provided to establish and maintain the desired operating temperatures. The plant layout considerations and need for hydraxdic transient analysis bsted in the section on naphtha are also appUcable here. 

Fluid Tracing Systems Steam tracing is the most common type of industrial pipe tracing. In 1960, over 95 percent of industrial tracing systems were steam traced. By 1995, improvements in electric heating technology increased the electric share to 30 to 40 percent. Fluid systems other than steam are rather uncommon and account for less than 5 percent of tracing systems. 

This cylindrical, low-pressure, horizontal tank had a design rating of about 5 psig (0.3 bar). A steam coil heated this tank. The transfer line to the tank was steam traced and insulated to keep it clear, but the heat tracing and insulation system on the inlet transfer piping was less than ideal. The inlet piping had to be dismantled on several occasions to clear it because of solidification in the fine. (See Figure 6—18.) [7]... 

The entire 8-inch (20 cm) piping system was insulated and steam traced except for the heater tubes within the heater. Operations assumed the heat transfer fluid froze in the four heater tube passes. Each pass was a bare 4-inch (10 cm) diameter heater tube with 5 bends and the equivalent of 72 ft. (22 m) of straight pipe. The foreman and the operations team discussed the situation and decided to light and maintain a small fire on the burner to slowly thaw the material in the heater tubes. This method had been successful for a startup several weeks earlier. 

In the bottom-drive system, the vessel cover is free of drive components, allowing space for additional process nozzles, manholes, explosion venting, etc., as well as a temperature lance for direct, continuous product temperature measurement in the vessel. The top cover of the vessel is easily heated by either a half-pipe coil or heat tracing, which ensures that no vapor condensation will occur in the process area. 

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