RE: Underground Sloped Piping

From: <Conner>
Date: Fri Feb 01 2008 - 13:48:00 EST

Fyi there are many standards/references related perhaps to the subject you're talking about, including online e.g. <a href="http://10statesstandards.com">http://10statesstandards.com</a> <<a href="http://10statesstandards.com/">http://10statesstandards.com/</a>> and <a href="http://10statesstandards.com/wastewaterstandards.html.">http://10statesstandards.com/wastewaterstandards.html.</a> etc. [I believe there have been some studies and research by some folks perhaps suggesting some more velocity/grade on particularly large sewers etc., I suspect shear-related to minimize larger particle like grit build-up etc.) If anyone wants I could perhaps dig out an example of that as well.]

Randy Conner, ACIPCO

---

From: <a href="/group/PipingDesign/post?postID=9VjSOw4369b0J17d6exPkLW6dF9RBJQi2p8bwz13g7ehlSGquHJ2sORn0GHGWuEdaGBrTIvnPtoN7o0UA1vIxQFDbhg">PipingDesign@yahoogroups.com</a> [mailto:<a href="/group/PipingDesign/post?postID=9VjSOw4369b0J17d6exPkLW6dF9RBJQi2p8bwz13g7ehlSGquHJ2sORn0GHGWuEdaGBrTIvnPtoN7o0UA1vIxQFDbhg">PipingDesign@yahoogroups.com</a>] On Behalf Of Michael Roble
Sent: Thursday, January 31, 2008 7:20 PM To: <a href="/group/PipingDesign/post?postID=9VjSOw4369b0J17d6exPkLW6dF9RBJQi2p8bwz13g7ehlSGquHJ2sORn0GHGWuEdaGBrTIvnPtoN7o0UA1vIxQFDbhg">PipingDesign@yahoogroups.com</a> Subject: [PipingDesign] Underground Sloped Piping

I've been working on some sanitary drains recently, and I'm pretty familiar with calculating the drop across whatever distances I'm running. However what I'm curious about is why is there such big discrepencies between what everyone says is "standard"?

My main header starts off as a 4", and I hear 1/8" slope is required, and when it gets bigger I was instructed that 1/16" is ok from then on. Then as we go on, I hear "Instead of 1/8" use 1' of drop per 100'.." which is pretty close to 1/8", (1/8" = .01, and 1' per 100' = .012), but then I'm handed a chart printed from the internet regarding Manning's equation of 2' per second flow, and it's telling me the factor is like 0.0084 for a 4" and it slopes less and less as you get into larger sizes.

I completely understand that these numbers are probably miniscule differences at best, I'm just curious as to why there's so many different ways and outcomes to reach a factor? I'm at home now, I went to look at the National Plumbing Code today at work, and someone has it signed out, so I'll have to wait to check on that when it's returned.

I just figured I'd try to ask what you guys think and what you guys normally use.

Any input is greatly appreciated.

Michael Roble
Piping Designer
Continental Design And Management Group
Pittsburgh, PA

_________Confidentiality Notice_______________________

This e-mail and any files transmitted with it is confidential and is intended solely for the use of the individual(s) or entity(ies) to whom this e-mail is addressed. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, be advised that you have received this e-mail in error, and that any use, disclosure, dissemination, forwarding, printing, retention or copying of this e-mail is strictly prohibited. If you have received this e-mail in error, please immediately return this e-mail to the sender and delete the e-mail from your system. Thank you.

[Non-text portions of this message have been removed] Received on Fri Feb 01 13:48:00 2008