1. The pressure difference between the inside and outside of the cylinder makes the cylinder wall bear a certain amount of acting force, which varies with the change of the unit load. 

2. The force from baffle plate and nozzle acted on the cylinder

This is caused by the pressure difference before and after the baffle plate and the reaction when the steam flow flows through the nozzle, this force varies with the change of load.

3. The weight of the cylinder proper and the parts installed on the cylinder. 

4. The bearing block and the cylinder are cast into a whole or the bearing block is bolted with the unit of under the cylinder, the cylinder also bears the weight of the rotor and the unbalanced force generating during the rotation of the rotator. 

5. The force from the steam admisson pipe acting on the cylinder. 

6. During steam turbine running, the temperature difference exists in the cylinder parts, causing extremely complex thermal stress.