knife gate valve
Y-strainer is an indispensable filter device for conveying medium. Y-type filter is usually installed at the inlet end of pressure reducing valve, pressure relief valve, fixed water level valve or other equipment to remove impurities in the medium. Y-strainer principle and technical parameters
A valve is simply a device that directs or regulates flow by opening, closing or partially obstructing passageways.
Depends on the valve type and style.
Plug valves are valves with cylindrical or conically tapered "plugs" which can be rotated inside the valve body to control flow through the valve.