plumbing Home › Forums › Archives › Old Bulletin Board Archives › plumbing This topic has 0 replies, 1 voice, and was last updated 27 years, 3 months ago by Monasilla. Viewing 0 reply threads Author Posts 22 Aug 1997 at 2:19 am #285460 Monasilla I would like the formula for figuring invert elevations. Author Posts Viewing 0 reply threads The forum ‘Old Bulletin Board Archives’ is closed to new topics and replies.