Please guideline to me.

I have the revamp project for expansion refinery. The client need to increase capacity to double. So many equipments have been up size, increasing control valve sizing and also increasing fluid's velocity.

My question is :

1. Do I need to re-calculate on those existing lines (completed long year ago) which require to increase size of control valve only by remove reducer out and up size one step ( 10 to 12 inch ), piping size and routing still same as it is. Many many locations provide like this case. If no need how I can told the reason to the owner.


2. And on the other existing line that velocity is creased how I can told the owner that these velocity is not effect to the systems and safe enough to not re-calculate those lines. And vibration may not occur if support are provide correctly.

Thank very much.