141. How Can I Evaluate The Thermal Relief Requirements For Double Block-in Of 98% Sulfuric Acid?
API RP 520 gives equations to calculate relief requirements. For thermal relief, a very simple formula requires the heat input and the coefficient of thermal expansion of the liquid. The heat input could be a problem. If you are concerned about sulfur in a line that is part of a heat exchanger system, then the heat is simply the design capacity of the heat exchanger. If it were a pipeline in the sun, then you would have to calculate the amount of heat that the sun can put into the pipe. You can get the coefficient of thermal expansion from your supplier or any book on sulfuric. You can also calculate it by taking the specific gravity at two different temperatures and divide the SG difference by the temperature difference. Coefficient of expansion has the units of 1/0F.
