pressure sewer system modeling 1

[walkertexasranger]

I posted this with mechanical/piping forum, but it may be better fielded by the civil crowd. Anyway:

I have a good working EPANET model of a large pressure system that has, say, 1000 2 HP grinder pump stations, 100 5 HP grinder pump stations, and 10 10+ HP pump stations. Obviously, all of these pumps are not running at once. If they were, the model correctly indicates that many would not be able to overcome the line pressure.

What ratio of pumps should I cut on to prove to myself that the system works? I have been unable to find any regulatory information. I know from inspection that the addition of one more 2 HP ginder pump has no ill effects but I need to demonstrate this for the State.

 

[semo]

I am at home and don't have the info in front of me; but, do a search on some of the grinder pump manufacturer's (e-one, myers, etc.)

They have some design literature posted that gives this type of info. EPA also has an equation that can be used as well. They don't all come up with the same answer; but, close.

 

[walkertexasranger]

Thanks for the feedback. A quick browse through the EPA website did not yield anything that looked promising. If you have a link, it would be much appreciated.

 

[walkertexasranger]

I managed to locate a pressure sewer design manual on the e-one site that has what I am looking for.

http://www.eone.com/downloads/extreme/lpsdesign.pdf

 

[bimr]

My understanding is that the firms selling these systems have developed a probablity curve that estimates the number of users that are pumping at any one time.