antonio saura Cebrian
where is the corrosion problem in all of them or near to the heater?how many steam or BFW Do you used? which is the inside diameter for those tubes?
what type of material are you used in those elbows? 9Cr-1Mo (steel) internally hardface with 309L/stellite overlay or similar (this is the typical material required for steam/air decoking) this have to be the material for all the elbow from the outlet heater until you reach the swing elbow
With this specification we never found any corrosion problem in our coker units
I’m sorry for my english