In which direction should the frame arms of upright sprinklers be oriented in relation to the installed pipe?

The frame arms of upright sprinklers should be oriented parallel to the installed pipe. This alignment ensures that the sprinkler operates effectively by allowing the water spray pattern to be directed towards the intended area for coverage. When the frame arms are parallel to the piping, the sprinkler can utilize its designed distribution pattern to cover the area below without obstruction.

Maintaining this parallel orientation is key to achieving the proper hydraulic performance of the sprinkler system. It helps avoid interference with the spray from adjacent sprinklers and ensures that water is effectively delivered to all parts of the protected area. Misalignment, such as positioning the arms perpendicular or at a right angle to the pipe, could lead to reduced efficiency and inadequate coverage. Vertical orientation would not be appropriate as it does not align with the pipe structure, compromising the effective functioning of the sprinkler system.