Generally 1/8" to 1/4" per foot. Any more than that the liquid waste may run faster than the solids and not carry the solids down.
Drainage fittings have pitch and are not pressure rather
Wouldnt that depend on the diameter of the piping?=12" drainage requires less pitch then 4"=
ASME B31.1
A line used to predetermine the fall /pitch of the drainage or venting lines
What pressure or are you asking drainage THEN What pitch are you using
Piping is installing pipes such as waste /vent/ soil / gas/ water/ etc.
by calculating the fixture unit requirements and the pitch of the piping for proper drainage
4
The maximum number of drainage fixture unit on a 2" drain line depends on the slope of the drain line. 21 units are allowed if the slope is 1/4' per foot, and 26 units are allowed if the slope of the line is 1/2" per foot.
Dirty water drains will normally be of 100mm internal diameter, laid to a fall of not less than 1 in 60 to avoid settlement of solids or semi-solid material. The maximum distance between manholes in straight lines shall be 90m.
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There are lots of possible answers,A drainage basinA watershedA drainage systemDendritic drainage patternTrellis drainage patternParallel drainage patternRectangular drainage patternRadial drainage patternAnnular drainage patternDiscordant drainage patternA spring headTributariesConfluencesA river system