Hello, There are several potential causes for a ball valve to close very hard: - Debris or Contaminants: Particles or debris inside the valve can obstruct the ball, making it difficult to close. - Wear and Tear: Over time, the seals and seats can wear out, causing increased friction. - Improper Installation: If the valve is not installed correctly, it can lead to misalignment and operational issues. - Lack of Lubrication: Insufficient lubrication can cause the ball to stick. - Pressure Issues: High pressure in the system can make it harder to operate the valve. For your application, you could consider checking for debris and ensuring proper lubrication as initial steps. If the problem persists, you might want to look into replacing the seals or the entire valve.