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.

Just my opinion say I am having these problem:
1-I might check the exact change in weight from smaller to bigger control valve-be sure you get the exact weight of the actuator. Most likely you don't have the original stress model and so if you have all the necessary information to run it I would say better run in Caesar if there is a significant increase in weight. By running the old control station for SUS case requirment, you will have SUS case stresses and most of the time the highest are on the weld point of reducer (increaser). If these stresses are high originally say 90%+, I would say increasing the weight of control valve may simply raise the stresses. Please take note too that stress engineers don't have uniform limit of maximum stress on SUS case. Most of the projects and company standard I met set this number if possible to 65%maximum simply because this is primary stress - it is always there. Technically the hot SUS is even giving a higher figure than cold SUS. So to me, if you are getting say mid 90%s of SUS stresses when adding the new control valve, I would rather recommend additional support close to the control valves to drop the SUS stresses. Honestly I met a lot of stress engineers letting go as high as 90% and I myself has raised this issue a year ago on this forum. So the deciding factor to analyze is for me the added weight.

2-The velocity issue maybe a process engineer issue say velocity increase will increase the pressure drop and is a direct component of pumps' dynamic head (may affect pumps' size)- so again it depend on how big is the change. If these system were subjected originally to vibration/pulsation analysis (say discharge of comressors), you might refer the significant increase in velocity to the right people for the proper ananlysis to bring the system into an allowable limit in vibration.

Just my opinion.

Was the plant originally so over-designed that a 2x increase in capacity is feasible ?? What about pumps, compressors, PSV capacities etc ??

EddieB_2070,

Thank you for your opinion. Appreciated that.

Movez,

This project has another new expansion project combine with original plant.

For new expansion proj, new pump & new compressor etc are added and connected to tie in point to existing.

But for existing plant, some equipments(column, vessel etc) are replaced and some piping system are require to change control valve size or add more psv but no change original routing.

Other suggestion will be appreciated.

Thanks very much.