Insulation for Pipes

In general, insulation data can be entered either on the Insulation tab or Heat Transfer tab. Only one of these tabs displays at a time. Insulation input depends on whether or not heat transfer is being modeled, and is an optional input. Insulation data is from the Nayyar Piping Handbook 2000Nayyar, M. L., Piping Handbook, 7th edition, McGraw-Hill, New York, NY, 2000. pages B.325-B.344.

If Heat Transfer Is Not Modeled

If heat transfer is not modeled, then a separate Insulation tab appears on the Pipe Properties Window. The insulation will have no thermal effect.

  • Insulation on Outside of Pipe or Duct - If the insulation is on the outside of the pipe or duct, it will have no hydraulic effect, and will only affect cost calculations if they are enabled.

  • Insulation on Inside of Pipe or Duct - If the insulation is on the inside of the pipe or duct, it will reduce the flow area and change the pressure drop calculations. AFT Fathom accounts for this diameter reduction in such cases. The user must enter the insulation friction characteristics.

If Heat Transfer Is Modeled

When heat transfer is modeled, insulation input occurs on the Heat Transfer tab. There is no Insulation tab in this case.

  • Convective Heat Transfer Not Used - If a heat transfer model other than convective heat transfer is selected, the effect of insulation is the same as discussed above for the non-heat transfer case.

  • Convective Heat Transfer Is Used - If convective heat transfer is selected, the effect of insulation is the same as discussed above for the non-heat transfer case except now the thermal effect of the insulation is accounted for.

Related Blogs

Let the Heat Flow: Modeling Heat Transfer in Pipes in AFT Fathom and AFT Arrow