Process Equipment and Plant Design
A stuffing box is used for

Facilitating smooth opening and closing of a valve
Reducing the resistance of fluid flow
Prevention of fluid leakage around moving parts
Absorbing the contraction/expansion of pipeline due to temperature changes

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Process Equipment and Plant Design
In the design of a shell and tube heat exchanger, the corrosion allowance

Need not be provided for non-pressure parts like tie rods, spacers, baffles, supports etc
For internal cover and tube sheet is provided on both the sides
All of these
For carbon steel and cast iron pressure parts is 1.5 mm (except for tubes) and for severe conditions it is 3 mm

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