antonio saura Cebrian
according that you said this header going to the heaetr is no symetrical , and that that pass is in the end of the header. what type of control valve do you have installed? long time ago in one of the our unit we have something like that (swing the flow and the pressure) we have install rotary or rotative valve, the problem was with the solid coming from the bottom of the fracc, because this solid was accumulating in this valve (the solid preffer go straight a head to the end of the header) until this valve
the problem was reduce when this valve was open for the operator , for that reason we took how rutine open this valve 100% and return to the initial position than fast as the operator can do it , one time for week
also if I understood you said if you put in bypass this valev it had the same behaivor, this swing can be for the velocity medium ? or some leak for the emergency steam?