Gate Valve

Gate Valves are by far the most widely used in industrial piping. That's because most valves are needed as stop valves - to fully shut off or fully turn on flow - the only job for which gate valves are recommended.
Gate Valves are inherently suited for wide-open service. Flow moves in a straight line, and practically without resistance when disc/wedge is fully raised.
The seating is perpendicular or at a right angle to the line of flow and meets it head on. That's one reason why Gate Valves are impractical for throttling service and for too frequent operation.
The difference between Sluice Valves and Gate Valve is that the Gate Valves are generally used for water or water like fluids, while aSluice Valve is recommended for Slurries.
Type of Valves: Non Rising Spindle and OS&Y Rising Spindle.
Operation: Manual, Gear Operated, or Motorized.
Cast Iron Valves Range: 50mm NB to 1200 mm NB, 
Cast Steel Valves Range: 50 mm NB to 300 mm NB
Forged & Bronze Valves Range: 15 mm NB to 50 mm NB