Process Equipment and Plant Design
When one of the fluids is highly corrosive and has fouling tendency, it should

Flow at a very slow velocity
Preferably flow inside the tube for its easier internal cleaning
Flow outside the tube, when the flow is counter-current and inside the tube when the flow is co-current
Perferably flow outside the tube

ANSWER DOWNLOAD EXAMIANS APP

Process Equipment and Plant Design
Generally, elliptical dished heads

Resist half the pressure rating compared to hemi spherical head provided on the cylindrical shell of the same thickness and diameter
Are approximately as strong as seamless cylindrical shell having the corresponding I.D and O.D
Are manufactured on 2:1 ratio of major to minor axis and is recommended to be used for pressure vessels operating above a pressure of 1.5 MN/m²
All of these

ANSWER DOWNLOAD EXAMIANS APP