Gate valve is usually used to cut-off medium, the entire flow channel is a straight-through passage when the valve is fully-open, and the pressure loss of medium running is minimum. Gate valve is usually for working condition in which the valve is not opened or closed frequently, and supports flashboard fully open or fully closed. It's not suitable for adjustment or throttling. Different materials may be selected for transportation of water, steam, oil, natural gas, nitric acid, acetic acid, oxidant and urea.