I need to reroute sump discharge. However, it a long way....

I have a Zoeller M98 1/2 hp pump which states 23' max head.

My 1 1/2 discharge is as follows approx:
from pit bottom to point it goes horizontal is 7".
Horizontal it goes 13'
then it goes vertical again 2' to come out the sill plate.
There is about 1' more vertical going out of the house where it drains to gravity.

That's 23' approx. not counting fittings which I assume add to the figure.


Am I going to burn out my pump doing this?
Am I computing the head footage correctly?

"Head" is the distance it goes up, plus any friction effect. YOu only have to worry about the lift NOT the horizontal distances.

You will be good to go. Just figure the vertical for head calculations- sure, there will be a few more feet added in for friction loss to fittings/pipe, etc., but that pump has you covered.

I was hoping and praying that you were going to tell me that horizontal distance is not calculated!!!

I have some negative slope on the horizontal... I assume that's not an issue either?
Is having that amount of standing water in the horizontal being held by a basic check valve an issue?



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No, that's the purpose of the check valve.

we recommend a check valve right after the pump. If you have a lot of pump action you would like a quiet check valve to prevent a "THUMP". The sponsor sells one here.

Do you know off hand or of a table that shows how much I should add for fittings?

use long sweep 90's or use two 45's to make a 90. this will minimize the resistance.
do a google search for 'friction loss for water pipe fittings'..
truthfully, if you can understand what they are saying, you are better than me.

You're overthinking this. According to the performance chart, at 15' TDH (probably where you are) you'll be pumping ~45 gpm. At 20' TDH, 24 gpm.

Using this chart, it appears I am busted:

[www.engineeringtoolbox.com]


From the pit up I have the following 1.5" fittings:

check valve
pvc gate valve
2 x 90
1x long sweep 90
then it goes horizontal....
end of horizontal portion is a Wye (cleanout on end and turns up 45).
1x 45 with a street 90 turning the pipe out horizontal thru wall.

unless I am reading and computing this wrong... I am way over 23' head now... (including the 8' of actual pipe length in the vertical position).



Edited 1 times.

Those are the equivalent length of straight pipe. You add those to the length of straight pipe you have, then go to a chart. It will give you the friction loss for 100 feet of straight pipe.

So am I still in the ballgame here? The feet given for each fitting isn't just simply added to the length of vertical pipe I have? Theres an equation I am missing then.... crossing my finger.

[performancepropumps.com]
Remember, the numbers are based on 100', so 160 is 1.6 in the example they use.



Edited 1 times.

I figure you'll be pumping about 25 gpm.

My heads spinning! Should have paid more attention in school.

I realize simply adding the equivilant length of fittings to the static head is not correct...

here is my approx. info:

Zoeller M98 1/2 hp with max head 23' and max flow rate 72 gpm.
(not sure of system capacity)
1.5 pipe.

static head (vertical pipe) is 10'
horizontal pipe length is 15'

35' feet is the approx. total equivilant length of fittings using the following chart [www.engineeringtoolbox.com].... however, I did not see an equivilant for check valve and a pvc ball valve.. so its likely a bit more.



Like I said, my head is spinning. Just want to know if I am good to go. Someone mentioned over thinking this in a previous post... I hope so, otherwise more $$ and time will need to be spent.

I think you'll be fine, provided 25 gpm is enough. If not, maybe you should be bottling it.

Thank you!

I found an equation at abe-research.illinois.edu/pubs/factsheets/SumpPumps.pdf

Since I don't know how to adjust the numbers for less than 100' feet of pipe I did a general calculation with numbers well above what I think I have and I seem to still fall less than the head max rating on the pump.

I probably f'ed up the numbers somewhere though and will be crossing my fingers when the pump is going off every 30 seconds during a torrential rain storm this summer!



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60 feet = .6 ?

you said 25 gpm estimate.

is this a fair way to assess that...

I have 18" basin. Pump float is off at 3" on at 9.5".

One estimate I read said 1" of water in 18" basin equates to 1 gallon.

So during heaviest rain I might see it switch on every 30 seconds. Each time pumping out 6.5" of water. Which is 6.5 gallons x twice a minute.

So the flow rate is 13gpm..........



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Unplug the pump. Fill your sump receptor to the top with water. Head outside with a five gallon bucket to the discharge terminal. Holding bucket under terminal and a stopwatch in your other hand, have someone plug the pump in. Begin the stopwatch as soon as water hits the bucket and stop it when its full. Calculate gpm based on five gallons per partial minute.

So using the on/off height of the switch to generalize system capacity is incorrect?

Since the tables/calculators use 100' of pipe to calculate the friction head and equivalent values, and the fact I don't understand how to alter the equation for shorter runs of pipe, I plugged in my numbers assuming I had 100' of pipe as well (although its less than half that). I also guessed at 35 gpm for system capacity.

Even using the inflated numbers the Total Dynamic Head falls below the max of the pump. So I assume with my actual numbers which are less than what I used to calculate this, I am ok.

So what I want to confirm is that the TDH doesn't rise with shorter runs of pipe and less GPM capacity?



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Shorter runs of pipe/less fittings will DECREASE TDH and INCREASE gpm. But the biggest factor in all is vertical lift. If you are calculating an inflow of 13 gpm during heavy rains, one would hope you have back-up measures in place. With that amount of water, you don't have a lot of wiggle room.