A multi-turn valve which has a gate-like disk and two seats to close the valve. The gate moves linearly, perpendicular to the direction of flow. This type of valve is normally used in the fully opened or fully closed position; it is not suited to throttling applications. Gate valves provide robust sealing, and are used extensively in the petrochemical industries. This class of valves also includes knife gate valves, conduit gate valves and
wedge gate valves. Knife gate valves have much thinner gates with knife-like edge, making them suited to use with floating solids, e.g., as in the pulp & paper industries. Conduit gate valves have a rectangular disk as the closing element. one
half of the disk is solid, to close the valve, the other has a circular port, which can be used to open the valve.
Wedge gate valves have a wedge-shaped gate which "wedges" between floating seats to close the valve tightly.

The above attached product's specification is as follow:

Design Construction and Specification:
Gate valves conform to API 602,BS5352,and ASME B 16.34, Each are tested according to API598 , and marking is per MSS SP-25.
Construction is as follows:
Full Port or Conventional Port
Outside Screw and Yoke (OS&Y)
Two Piece self aligning packing gland
Bolted bonnet with spiral-wound gasket, threaded and seal welded bonnet or threaded and pressure seal bonnet
Integral backseat
Socket weld Ends to ASME B16.11
Screwed Ends (NPT) to ANSI/ASME B1.20.1