Lateral Pipe or tube. In irrigation, the pipes/tubes between the zone control valves and the sprinkler heads or emitters are called “laterals.”A sewer lateral is the pipe that connects indoor plumbing to the sewer main. As illustrated in the diagram, there are both upper and lower private laterals. The upperlateral runs from the home or business to a cleanout at the sidewalk or sometimes the property line.

When the running pipe in a piping system need to add a branch,we may use a tee or outlets,the common degree of the branch direction is 90 degree which means the branch is vertical to the main pipe.

Some time the branch direction is not 90 degree to the main pipe,maybe 45° or other degrees,then we should use a lateral pipe fittings to design it.