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

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Process Equipment and Plant Design
Triangular pitch tube layout as compared to square pitch in a shell and tube heat exchanger

Both B and C
Permits the use of less tubes in a given shell diameter
Facilitates comparatively easier external cleaning because of large clearance
Permits the use of more tubes in a given shell diameter

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