The momentum change and the unbalanced internal pressure of the water leads to forces on the pipes
The force diagram in figure is a convenient method for finding the resultant 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.
Read the rest of this entry »

If a pipe is subject to a wide range of temperatures, the stress, lb/in² (MPa), due to a temperature change is
Read the rest of this entry »

The internal or external pressures on the pipe walls cause the stresses acting perpendicular to the longitudinal axis of a pipe.
Internal pressure creates a stress commonly called hoop tension

The sum of the forces in the horizontal direction is

pD=2F

where
p= internal pressure, lb/in² (MPa)

D= outside diameter of pipe, in (mm)

F= force acting on each cut of edge of pipe, lb (N)

Hence, the stress, lb/in² (MPa) on the pipe material is

pD=F/A= pD/2t

where
A= area of cut edge of pipe, ft² (m²)
t= thickness of pipe wall, in (mm).

Water hammer is a change in pressure, either above or below the normal pressure, caused by a variation of the flow rate in a pipe.

Read the rest of this entry »

This type of tube can greatly increase the flow through an orifice by reducing the pressure at the orifice below atmospheric. The formula that follows for the pressure at the entrance to the tube is obtained by writing the Bernoulli equation for points 1 and 3 and points 1 and 2

Read the rest of this entry »