mggyi2006,
Very good advice from PetersPhotograpy above.
I might add, that on the pump side of things, you will most likely be using a horizontal splitcase, double suction pump which is typical for pipeline service. Whether it is a single stage or multistage will depend on the pressure reqired; anything over say 500' of head will most likely require a multistage.
The double suction impeller allows a much lower NPSH Requirement (in a multistage, only the first stage will be double suction).
A vertical lineshaft pump or "can pump" is usually considered when NPSH Available is extremely low, or if footprint needs to be very small. Many times the decision to go horizontal or vertical is based upon Maintenance/Operations familiarity or preference with one style or the other.
Whatever style, it will need to comply with API 610 since you are pumping hydrocarbons. This narrows down the manufacturers considerably.
Next you will need to consider what speed to run at. This is a balance between cost and reliability. The faster a pump spins, the faster it wears out; as speed increases, wear increases to the CUBED POWER!
So you would want the slowest pump you can get; BUT, as speed decreases, head decreases to the SQUARED POWER! That means the slower you run, the larger diameter impeller required to meet the head requirement, and COST GOES UP with size.
Try to stay at synchronous speed for main design point; that is, 3600, 1800, 1200, or 900 rpm (you would only consider 3600 if that is the only way to acheive the head, its just too darn fast). Not relying on a VFD to hit the design point will earn you bonus points from the electrical guys as it simplifies their world.
When you do select a pump, make sure there is some "head reserve" capability; that is, select an impeller that is at least 10-15% smaller than the maximum diameter offered for that model. If your head calcs are off, or down the road you require more head, you can accomodate by putting larger impeller in existing unit.
Also try to select a pump as close to the Best Efficiency Point for that model. Again if your calcs are a little off, you will still be at a decent efficiency and won't overload your motor.
I would highly recommend calling one of the "Big Boys" in the pump world, Flowserve, Sulzer, Goulds, CLyde-Union. They have all been making these pumps for many, many years and probably have them all over your plant. Ask each one of the salesmen to drop by and visit you and show their best selection. Don't just ask one of them. You can get painted into a corner, and believe it or not, some pump salesmen are REALLY good at pumps and can teach you a lot. That is what they get paid to do; USE THEIR EXPERIENCE.
Good luck my friend!
