Gravity Flow rate calculation from atmospheric tank to truck

[HFCkh]

Need some help.

Have an atmospheric tank of sour gasoil (~30 ft of liquid)
Need to gravity flow from the tank to a truck (also vented and ~12 ft in height) via a 3" line (~60-80ft in length).
Question is how long will it take to fill the truck or what is the flow rate through the line so as to estimate the fill time for the truck.

Seems basic, but I am sure I am overthinking it.
Thanks for your help.

 

[MiketheEngineer]

Fairly simple hydraulics problem - don't remember equations - but any college text book will address this..

 

[HFCkh]

Problem is that I am not where the books are. So any additional help is good.

 

[ione]

Head available as height difference is dissipated through pipe friction losses + entrance and exit effect. This topic has been treated many times here. No direct solution available, you have to make some iterations starting with a guestimate of flow rate.

You can start giving a read to the thread below

http://www.eng-tips.com/viewthread.cfm?qid=289494

and then give a shot to the calculator at the link below

http://www.globalspec.com/calculators/vertical-tank-draining-time

 

[CastMetal]

This file has some basic fluid flow problems worked out in an excel format 20-30 of them you should find one that fits your situation

http://www.cheresources.com/invision/files/file/91-crane-fluid-flow-problems/