×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Force Main Connection

Force Main Connection

Force Main Connection

(OP)
A business owner is in need of a place to discharge his wastewater. The local Utility District told him to tie into a force main owned by the school district that I represent. We have determined that the force main has capacity to handle the additional load. The question is, is it possible to tie directly into a force main? If so, can anyone offer suggestions on how, or point me towards any resources that can provide instructions on how to make it happen?

RE: Force Main Connection

The forcemain is more than likely owned by the utility district, not the school district.  Nevertheless, the answer to your question is "it depends, but probably not without at least a griner pump." If the forcemain is beyond all local high points and acts under gravity flow the entire path to the WWTP then you could probably connect directly to it, but that's a very unlikely scenario and just because it's downhill all the way it doesn't mean that the pipe isn't surcharged at the connecting point (or will be in the future) due to a high flow rate. I know of such a situation where the business owner was allowed to connect to a trunk forcemain with just a grinder pump as it was near to the end of the line and the surcharge was not too great.  

RE: Force Main Connection


You have not provided much information as to the requirements for your project. You should note that the state plumbing code typically requires separate service connections from each property into the utility sanitary sewers.

What you are talking about is a small plumbing project. Talk to a pump vendor such as Myers:  

http://www.femyers.com/products/wastewater.html

Make sure that you buy a pump with adequate discharge head. The piping connection will probably be a Y fitting.
 

RE: Force Main Connection

The easiest way (for the school district) would be to require the use a tapping sleeve and valve to connect to the force main. This can be installed while the main is in use and filled with sewerage, so the School District will see no inconvenience. A valve box should be installed over the valve operating nut. This valve will allow the School District to isolate the business in the event the business has a problem. As to the business, his Engineer needs to know the profile of the force main in order to size the pump(s). One more thing you may want to include is a check valve at the tap to control water hammer, but I normally don't require one.

If you have contacts with either a water utility or utility contractor, find out where they buy pipe and fittings. These supply houses normally have a salesman that can offer advice on things like this. If you know the type of pipe used to construct the force main, a salesman could give you a manufacturer and number or name of the required fitting(s).
Steve
 

RE: Force Main Connection

The way I have always done this was to cut in a wye fitting and install a valve on the new line.  You can drain the force main by turning off the pumps and opening the check valve.  The wye fitting is incase you ever pig the force main.  The business owner will need a pump.  

RE: Force Main Connection

Sounds like Steve hit the nail on the head. A pig will turn through a Tee, however, some folks dont like to do a full sized tap - for example you'll usually do a 16"X12" tapping sleeve & valve rather than a 16x16 for tieing two 16" pipes together.

Depending on the new business flow rate in relation to the schools you might be running a smaller force main connecting to a larger one anyway.

If your flow rate is low enough check out eOne pumps. If it's a bit more than an eOne can handle I too would turn to a Myers. If you go with eOne I'd recommend specifying the oil resistant stators.  

RE: Force Main Connection

When you do your calculations, remember that your new pump will have to push the water in the utilities forcemain as well.  Most grinder pumps have suffcient head capacities to overcome this type of condition, but check it.

Check Valves and Shutoff Valves are probably a good idea.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources