Recent content by rutherford703

Piping class is normally determined based on the service conditions - pressure, temperature and commodity inside the pipeline. For the three phase separator, you have phase change - from liquid phase to vapor phase. Normally, chemical engineer decides the service conditions. Material engineer...

It all depends on your service conditions (pressure, temperature) and medium. Is the vessel full of liquid? Is the liquid flammable? Vapor pressure? Boiling point? Poisonous? "vessel being designed for atmospheric pressure" is not clear what the vessel design pressure is, 0 psig or 14.7 psig...

This is more electrical than chemical process. Let me try to explain the function of the process. In the drawing something showed as interlock is not an interlock, actually it is a controller. The controller input is from flow transmitter (normally called PV) with a signal of 0-24V and the...

Thanks for all your valuable information!

sorry the attachment does work Thankshttp://files.engineering.com/getfile.aspx?folder=4725df91-d3b7-416e-87aa-a8c20124d9c3&file=Naphtha_heater.pdf

The attached drawing is a naphtha heater. Naphtha can be blocked in while the steam keeps flowing. A thermal relief valve is provided for such a scenario. The PSV directly discharges to the OWS (Oil Water Sewer). We realized that it is not a good design; however, it is a grandfather plant. Does...

Good point Artisi. You deserve a star. Yes. There is some entrained solid in the naphtha. Even the recirculation control valve has some erosion issue. Thanks.

Thanks everyone for the valuable opinions. As Artisi required, I attached the pump performance curve. The rated point is far away from the BEP. The pump casing eroded as in the photo only lasted for three weeks running. Thanks...

Seal(?) damagehttp://files.engineering.com/getfile.aspx?folder=1c792dc0-888e-4f7c-b62a-26d213f7edd8&file=seal_damage.jpg

Here is the photo for impeller damagehttp://files.engineering.com/getfile.aspx?folder=8ea7a309-140c-471c-8ab8-12d063c3a22e&file=impeller_damage.jpg

I didn't realize that the forum does not allow to attach multiple documents which I thought to be posted. Some new photos here. Sorryhttp://files.engineering.com/getfile.aspx?folder=4ad50482-8bd4-4ed5-911d-35088eadf4db&file=Casing_damage.jpg

Actually, I rechecked the operating manual, the minimum clearance between the casing wear ring and impeller wear ring was followed API standard and is about 0.010". I haven't seen the wear rings after they were taken out and I am not clear how damage the wear rings are. I see the problem may be...

Hi 1gibson, Even if I unwilling to admit you are right, the erosion mode predicts what you said. As a process engineer, I cannot believe that the apparant error cannot be found by our pump specialist and causing the pump failure again and again. It is the very likely the root cause. I give you...

Thanks all of you for your valuable opinions. I have to agree that the damage of the pump is due to erosion. While I cannot answer all your questions, I attach the mechanical drawing for the pump and show where the damages are. It seems to me that the extensive erosion on the casing is a little...

Here are some photoshttp://files.engineering.com/getfile.aspx?folder=5e94b4cb-cfed-4515-8411-46bc04c24227&file=inlet_surface.jpg