Search under "The Engergy Institute" formerly Institute of Petroleum. You may find EI IP-MCSP-P15 2005 to be the model code of safe practice part 15, Area Classification Code for installations handling flammable fluids. Where is the project destination?
finechemical,
Please start a new thread. Advise the type process application etc.
You need some real world information like the fluid, some inlet properties and outlet requirements. Let us know that this is not a homework problem if applicable.