Process Equipment and Plant Design
Seamless pipe is made

Both B and C
By forging a solid round, piercing it by simultaneously rotating & forcing it over a piercer point and further reducing it by rolling gas drawing
By extrusion & casting into static and centrifugal molds
From rolled strips formed into cylinders and seam-welded

ANSWER DOWNLOAD EXAMIANS APP

Process Equipment and Plant Design
Smoker's equation for the calculation of number of equilibrium stages in a continuous binary distillation column is used, when the

Feed is not at its bubble point
Relative volatility is close to one (e.g., separation of close boiling isomers)
Number of equilibrium stages required is likely to be very small
Number of equilibrium stages in only stripping section is to be calculated

ANSWER DOWNLOAD EXAMIANS APP