Normally, elbows are used for changing the direction of pipeline which could be done by one HDPE manhole in the same way. These elbows produced according to the information which is provided by customers such as diameter and degree of fraction. In places which the fraction is more than 30 degree, it’s recommended to use Compound Elbow. Compound elbow contains several fractions. For example, for an elbow with degree of 50, the compound elbow with two fraction of 25 degree could be replaced. This issue leads to less impact insert to the elbow by the fluid inside which may happen because of this change in direction.
Elbow and tree are such a places in pipeline that could cause eclipse in the pipeline. As a result, it’s recommended to use HDPE manholes for redirection of pipeline is small diameters.