PetroStreet

Normally in Pipe racks , Utility Lines are placed in the upper deck , and Process lines in lower deck of Pipe rack . Why is it so, whats the technical reason?

Pipeline destination and equipment elevation sometimes define the placement of pipelines in the piping rack as in your case. Normally, utility lines have to travel long distances and it is preferred to place them on the top rack and short process lines are placed in lower rack.
There are many other factors also need to be considered during placement of pipelines in the piping rack.

I have to route a line from equipment to the pump . My Question is

1. Normally we have seen that Pump suction nozzle is of small size as compared to pump suction line . Why it is so?

2. For that it is also recommended that pump suction line must be kept as large as possible to as long as possible until it reduces after Eccentric reducer (FOT) in front of pump suction. My question is why cant we reduce line just after it exit from the equipment to meet the pump nozzle size..??

Regards.

1. Pump nozzles are of small sizes just to accommodate a properly sized eccentric reducer in horizontal position which helps avoiding formation of gas / vapor pockets just before the entry of fluid in the suction nozzle.
2. This is not the case in normal applications. Suction line is considered to be of some specified length only in the case of pumps having larger delivery like cooling water circulation pumps. But normally suction line should be as short as possible to avoid formation of any eddies over the length. We require to eliminate gas or vapor pockets / eddies formation just at the suction of the pump; this is the reason why we provide ER (ecc. reducer) directly at the suction entry and not at the equipment outlet nozzle.

1. Fluids tend to flow with lesser gas pockets if they are provided with a Converging effect like in the case of ER. That's the main reason of having a smaller sized nozzle at the pump suction to converge the inlet fluid.
2. No. Line shall be reduced at the suction inlet by providing ER. Reducing it at the equipment would not serve the purpose.

Moreover, just for your information, fluids also face pre-rotation phenomena when not provided a straight length before suction. If there is a elbow at suction due to some space limitation, vortex breaker or some baffle arrangement must be considered.

Thnx.

You are welcome.

What are Piping Tie - in Points ? what are the requirements for their safe execution ?

Regards

I would advise to please raise a new thread.

Is there any sequence which must be followed for the placement of utility lines (Nitrogen , Air , Steam, Water) on pipe rack?
If yes

1) Whats the reason and why?

Regards