Coke Gas Valves (Carbon Steel vs Ductile Iron)

[Valving]

A client who owns an old iron &steel plant is building a new coke plant. Existing plant is old and mostly D.I. large gate valves sizes around 1000 mm (40") were used thus the staff is again considering to use D.I. gate valves. Temperature is not much and design pressure is 16 bar.

I am trying to compare the use of carbon steel valve and D.I. gate valves and want to write here considering that someone could comment something I can not think about.

 

[gerhardl]

What is the media? Why gatevalves?

Double eccentric (or even centric) (clad ?) BFL valves possible? (Knifegate valves possible?)

Operator type? Opening and closing time requirements?

PN16 bar class? Operational real pressure, max operational delta P? Pressure test requirements for body and gate/disc at site? Temperature? Impurities?