It is the force generated due to the pressure inside the expansion joint. Pressure thrust is calculated by multiplying the area of the mean bellows diameter by the pressure.
![Bull 02 a](https://usbellows.com/wp-content/uploads/1990/07/bull_02_a-300x160.jpg)
It is the force generated due to the pressure inside the expansion joint. Pressure thrust is calculated by multiplying the area of the mean bellows diameter by the pressure.