Residential grinder pump system questions

[xjken]

Hello all.

I found a bit of info doing a search here, but I have a few more questions. I am a consulting engineer. usually do commercial, but i got this job to provide an ejector for a residential 1-family house.

1. is a duplex gringer overkill? should i just do a simplex?

2. whats the usual sizing for these? #bathrooms? sqft of house? # of people?

3. any preferred manufacturer's?

any tips on sizing and spec'ing would be great!
thanks all.

ken

 

[francesca]

Is there a particular reason you need a grinder pump for this home? Are they trying to serve a basement that cannot gravity drain to the city sewer? Will you be pumping directly into a city sewer? Or will it be into a septic tank?

The only experience I have with individual home pumps was for a STEP system. We used Orenco Systems' pumps, but not their tanks (used a local supplier). It probably doesn't apply to your project, but they do have an informative website and they sent me a wealth of information (which I left behind at my old company when I went back to school).

 

[xjken]

yes, cannot gravity feed to the city sewer main. the main in the house will need to pump up to the city main in the street.

 

[bimr]

1. Most of these sewage applications only use a simplex pump.

2. These pumps generally do not run all the time, so the sizing is not really accurate. The pumps generally operate at 5-45 gpm, depending on the discharge head that you have to pump against. Unless you have some extreme discharge head condition, you will probably see 40-45 gpm pumping capacity.

If you go to Zoeller.com, they have a sizing program. You can size by the house method or by the fixture method.

Unless you have an very large house, go with the standard simplex pump package. You can double check the size of the sewage pump against the capacity of the water line into the house.

3. There are numerous vendors of these small pumps.

 

[LHA]

Agree with all bimr says.

Hydromatic and Goulds are common & reputable US manufacturers.

Engineering is the practice of the art of science - Steve

 

[xjken]

thanks for the replies everyone.

I thought a duplex was a bit much. My boss put a duplex in the proposal and i'm trying to convince him its not necessary.

I saw on another thread the e-one pumps are pretty popular. any good?
I will check the other brands mentioned above. I've used goulds before.

 

[semo]

Let me make the recommendation that you specify a 1 hp motor on the pump as well.

Many suppliers utilize a 1/2 HP as standard and these motors can be under a load because they not only drive the impeller; but, they also drive the cutters.

We've seen better lifespans with the larger motor and most manufacturer's can supply a 1 hp motor.

 

[jmrosell]

i would also suggest the 1 hp motor. we have used flygt and zoeller pumps and had good luck. i would check with your local authorizing agency to see what they spec.

 

[xjken]

well, i selected a zoeller system.
For grinder pumps, it seems as though they only have a 2hp model. (the 820 or 840).
I selected this pump with the panel, basin, etc to make a complete package system.
Zoeller has a nice website! selection progtam, details, specs, cad details... very nice.

 

[Hackenthorpe]

I'd recommend that you pick a pump brand based on what is readily available in the area. Grinder pumps break down, and its probably more important to find one that can be readily serviced than to find the most efficient one. This especially applies to a simplex station.

 

[nackra]

http://www.eone.com

Some of my clients have selected E-One over grinder. A little more expensived up front, but reportedly more reliable. Agree w/ Hackenthorpe that you MUST have LOCAL SERVICE as priority.

 

[runoff]

I just got through designing a subdivision grinder pump system forced main. It is a 20 home subdivision that had problems with septic field conditions. So as a consultant I recommended a grinder pump system since a sanitary sewer ran 520 feet from the homes. The county accepted the proposal and the local authority wanted us to use Myers and I have attached their website. I have also designed systems using the E-One systems. I prefer E-One over Myers but the County wanted Myers and had specified them in their local requirements. So, I had to use them. We designed out a 2hp system for an average bedroom size of 4. It is really not that difficult but since you are pumping up to the local service, you might have to put a little more thought to it. Myers has a program that you just plug and chug the numbers and it will give you the size of the piping, pumps sizes, velocities, air release valve arrangement and other requirements that makes the system work correctly. Hope that helps.

http://www.femyers.com/index.html