Connections bulletins PD-1 through PD-4 discuss some of the specific applications of the design of a properly restrained pipeline. PD-2 specifically addresses horizontal bends and the various parameters involved in the design process. PD-3 applies those parameters to the design of vertical offsets and tees. Finally, the design of reducers, dead ends, and miscellaneous fittings is discussed in PD-4. This bulletin delves into a more detailed discussion of the bearing and frictional resistance forces at work to balance thrust forces generated in pressurized pipelines. To see how this information relates to the various pipeline elements, please refer to the other Connections bulletins.