The gate valves operated having a handwheel or by using electric actuators are popular from aoaltwar's blog

A gate valve is considered the most widespread form of industrial valves for pipelines. Its application area is quite wide. The gate valves operated using a handwheel or by making use of electric actuators are popular gate valve. A pneumatic or possibly a hydraulic actuator can be applied likewise.

Gate valve seize up because within the water that circulates through pump throughout the central heating system, eventually gathers of iron and scale deposits, at the same time as other deposits that circulates, including hot and cold water systems. All the deposits usually stick to rough areas in excess of smooth areas, which is often valves. The deposits get involved the mechanisms creating the moving parts to jam up as opposed to move smoothly.

How do I repair my gate valve without replacing it
If you intend to repair the gate valves instead of replace it, so long as the valve spindle isn't damage then all that you should do is grab the valve out from the gate valve body and wash it up fully making certain there is no deposits left. Once the gate valve is fully clean, you'll need to greece the gate valve up, so that there is absolutely no friction between brass wear.

With the exception of parallel disk gate valve that has parallel seats, other types namely, solid wedge gate valve, flexible wedge gate valve and split wedge gate valve have inclined V-shaped seats just like a wedge. The Wedge gate valve is considered the most commonly used valve. This valve could be installed in any position.

Solid Wedge: Solid Wedge Disks are most regularly used because of simple and easy less expensive design.
Flexible Wedge: A Flexible Wedge gate valve features a disk that has a cut round the perimeter. A shallow cut gives less flexibility. A deeper cut provides more flexibility. Flexible Wedge gate valves tend to be used in steam systems. The flexible gate prevents the disc from binding into your seat once the lines are heated which may cause some distortion inside valve bodies check this link.

Split Wedge: Split Wedge gate valves are of ball and socket design. In a split wedge gate valve, the 2 main disk halves have outward resistant to the body seats by the spreader following the disk has become fully lowered into its seating position.