Y StrainerPVC

A minimum volume (10% ~ 20%) is considered in expansion tank at start-up in cold conditions. As heating is started volume expands and tank sizing should be such that expanded volume fills (70% ~ 80%) of tank volume.

Vcold = Volume of the entire heat transfer (including piping, heat exchangers and cold fluid in expansion tank at start up)

Expansion tanks are important to the operation of heat transfer systems. They are designed to account for the volumetric expansion of heat transfer fluids as a result of temperature increase. Expansion tanks also remove moisture, non-condensables, degradation by-products and entrained air during startup and operation.

Y Strainerfilter

Y StrainerValve

In this article, we present the sizing of an expansion tank using Relatherm HT-1, a high flash heat transfer fluid as an example.

Size an horizontal expansion tank for hot oil system using Relatherm HT-1 as Heat Transfer Fluid. The fluid is heated from 30 °C to 330 °C. System hot oil volume is 7.87 m³. Assume L/D to be used as 2.5. Thermal fluid density is 861.91 Kg/m³ at 30 °C and 752.17 Kg/m³ at 330 °C.