×
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

Blueprint Elevation Query
2

Blueprint Elevation Query

Blueprint Elevation Query

(OP)
If the invert elevation of a pipe is 93.25', isn't this the distance down from grade? If so, when calculating the upstream invert elevation 85' away at 2% grade, why is the answer 95.02'? Isn't this a deeper point? What am I missing here?

RE: Blueprint Elevation Query

Some arbitrary, likely immovable, point on or near the site has been chosen as 100' elevation.  Everything is then relative to the theoretical 0 associated with that.  Higher numbers are closer to the sky.

Mike Halloran
Pembroke Pines, FL, USA

RE: Blueprint Elevation Query

A lot of times the architect picks the first floor slab elevation and calls it 100.00'.  Inside elevations are taken from that point of reference.  

With plumbing piping, the inside invert elevation is also taken in reference to that elevation.  Therefore underslab piping will be less than 100.00.  With required negative slope, the invert of a plumbing pipe will get less.  That is why the numbers decrease in the direction of flow.

What gets sticky is that the plumbing piping ties into site piping and the civil engineer who designs the site piping uses inverts which are typically from a site survey with inverts based upon that with numbers in the hundreds or thousands.  

It is the plumbing designer's responsiblity to keep them straight.

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