If a very small valve opening, the opening of the fast flow rate will have a lower side flashboard cavitation, and accompanied by intense vibration and noise, long operating expenditure, and body tend to increase the metal gate cavitation occurs.
If the valve working condition in the middle of opening, the brass gate valve because it is supported on both sides of the rail, closed the whole time with a close, and the middle position, the valve plate and have a large gap rail vibration. Therefore, even in a low incidence of cavitation of the region, a long time to reduce expenditure valve operation, rail deformity can occur, wear or damage, and as a result of contact with the valve seat is not comprehensive, and access to parts of the surface high pressure, often will have to bite corrosion or adhesion, therefore, should not be used for flow control. Would also like to note that the valve in a small opening, the flow changes, and if an emergency brass gate valves, pressure will cause a sharp increase or create negative pressure, especially when the valve clearance of the resulting water hammer.