Cut-off valve, also known as the cut-off valve, is a forced sealing valve, is a kind of cut-off valve. There are three types of connection: Farlane connection, thread connection and welding connection.
Our country valve"Three changes to" has provided that the flow direction of the valve, are used from top to bottom, so the installation direction. The globe valve is designed for low inlet and high outlet to reduce flow resistance and save effort when opening the valve. When the valve is closed, the packing between the valve shell and bonnet and the packing around the valve stem are not subjected to force, so that the medium pressure and temperature do not affect the valve for a long time, which can prolong the service life and reduce the chance of leakage.
In addition, the valve can be closed in the state of replacement or additional packing, easy to repair. In general, globe valves are low in and high out, however, there are some special cases of globe valves are high in and low out: high pressure globe valves larger than 100mm in diameter due to poor sealing performance of large diameter valves, using this method to cut off the valve in the closed state, the media pressure acting on the disc above to increase the sealing of the valve.
Two globe valves in series in the by-pass line. The second globe valve requires"High in and low out". In order to ensure the tightness of the valve during a maintenance cycle, two globe valves in series are required for valves with frequent open-close operation. · boiler exhaust, vent shut-off valve boiler exhaust, vent shut-off valve is only used in the process of boiler start-up and water supply, for this reason, some power plants in order to improve the tightness of such valve installation direction"High in low out.".
