additional steam valve的用法和样例：
- This valve is not to be used as a steam valve.
- These are not to be used as steam valves.
- Presents the development and use of new stainless steel heap welding technique for main steam valve sealing surface.
- Servo unit can adjust the opening size of each steam valve with responding to the electro-instruction sent from DEH.
- For surfacing welding roller and over-heat steam valves.