Thermal

[chem101]

Hello Every One:
Under What cercumstances API 520 recommends 34D1
Size PSV(Thermal Conditions). Doesn't it depends on thickness of pipe.Do we have to use 3/4D1 PSV for all and every situation.
Thanks allot

 

[ggordil]

API recommends a 3/4"x1" valve for most systems. However, depending on the situation, calculations may be required. API gives a formula to use that is based on specific gravity heat capacity, and an expansion coefficient.

One note, if the heat that cause thermal expansion is above the boiling temperature of the fluid at the relief temperature, you will have vaporization. In that case, a 3/4"x1" will no longer provide adequate capacity.

 

[skearse]

Probably more than you ever wanted to know...

http://www.chemicalprocessing.com/articles/2001/324.html?page=1