Water shield in Top Nozzle of coke drum. 1

Height of water shields are site specific as depends on firefighting strategy and operating pressure in firewater main during design fire.
A vessel skirt may have not firefighting means other that a watershield while a coke drum bottom nozzle may be sprayed by a firebrigade.

Your question is not clear. What is design of this watershield? Can you provide a sketch? Anyway process unit design documentation contains all answers you need. You should ask persons involved in design of this coker unit.

More details = better comments.

@shvet thank you for your response. Im talking about highlighted plate in attached sketch. this is top nozzle on coke drum.

My question is why this plate ( water shield ) has been provided ? it is not provided on any other nozzles on top head of coke drum.

A watershield on other vessels have the same design?

water shields are not provided on any nozzles for other vessels.

only few vessels have water shield with similar design just above skirt to shell joint.

Are those skirts protected from overheating by a fireproofing material, e.g. bricks cladding?

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Yes, those skirts are protected from fire by fireproofing material.

Sloped Rain Shields like the one shown are used to protect the the unjacketed annular portion of the insulation or fireproofing from absorbing water during a rainstorm. Coke drums operate cyclically so they are susceptible to Corrosion Under Insulation when they're not in service, so the insulation needs to stay dry.


-Christine

@Christine74 thank you for your response.