FORCES DUE TO PIPE BENDS
It is a common practice to use thrust blocks in pipe bends to take the forces on
the pipe caused by the momentum change and the unbalanced internal pressure
of the water.
The force diagram in Fig. 12.12 is a convenient method for finding the resul-
tant force on a bend. The forces can be resolved into X and Y components to find
the magnitude and direction of the resultant force on the pipe. In Fig. 12.12,
V1 velocity before change in size of pipe, ft/s (m/s)
V2 velocity after change in size of pipe, ft /s (m/s)
p1 pressure before bend or size change in pipe, lb/ft2 (kPa)
p2 pressure after bend or size change in pipe, lb/ft2 (kPa)
