They are placed in pipelines as isolating valves from aoaltwar's blog

Gate valves are trusted for all varieties of applications and so are suitable for both above-ground and underground installation view more. Not least for underground installations, it can be paramount to decide on the right form of valve in order to avoid high replacement costs.

Gate valves are equipped for fully open or fully closed service. They are set up in pipelines as isolating valves, and will not be used to be a control or regulating valves.Operation of the gate valve is carried out doing an either clockwise to shut (CTC) or clockwise to open up (CTO) rotating motion from the stem. When operating the valve stem, the gate moves up- or downwards about the threaded part in the stem.

The forms of gate valves may be divided into wedge disc gate valves and parallel disc gate valves in line with the sealing surface configuration. Wedge disc gate valves might be further separated into: single gate, double disc and elastic disc; parallel disc gate valves could be Divided into single disc type and double disc type. According to the thread position in the valve stem, it is usually divided into rising-stem gate valve and non rising-stem gate valve.

Installation and upkeep of rising-stem gate valve:
Handwheels, handles and transmission mechanisms will not be allowed to be utilized for lifting, and collisions are strictly prohibited.The double disc gate valve must be installed vertically (that is certainly, the valve stem is with the vertical position plus the handwheel reaches the top).The gate valve which has a bypass valve needs to be opened before opening (to balance for most difference between the inlet and outlet and lower the opening force).The gate valve with transmission mechanism really should be installed good product manual.

As the gate or wedge must travel throughout the entire cross-section with the valve bore, the general height of gate valve is larger in comparison to a ball valve the quarter turn valve and will not require vertical movement in the stem.

Gate valves are offered with renewable seats that happen to be usually challenging to change out in-situ.
The valve flow characteristics of gate valve might cause high velocity of flow to happen for longer duration whilst the opening or closing the valve as a result of slow movement of wedge or gate ball valve . High velocities might cause erosion of seat along with the disc thereby decreasing the design life in the valve. This condition can also be referred to as “wire drawing” effect.