Shut-off valves and its typical representatives
First, we list the devices that are related to shut-off devices and are the standard representatives of such fittings.
- Gate valve. Serves as a regulating function, which makes it possible to completely seal the passageway, by overlapping it with a locking element.
- Gate valve. Provides shut-off functions, due to the sealing in the body of the access opening thanks to the disk shutter.
- Crane unit. Provides shut-off and control functions, sealing the access opening thanks to the element in the form of a body of rotation.
Let's look at the design of each device and consider their advantages.
The design of the valve is most often used for flow regulation, and the locking function can be called secondary. It is simple, and resembles a T-shaped tee, in which the piston is placed in a vertical section, moves along the axis, and a water pipe passes through the upper bar. By sliding down the locking element, it is possible to achieve partial or complete sealing of the water supply line. The locking elements can be displaced from the movement of the piston rod, which is controlled by a lever or valve. The valve, in turn, can be called the best control device. It is able to change the pipeline characteristics with high accuracy.
Unlike the valve design, the valve design is used only to seal the pipeline. It performs the function of constipation, but it is not possible to adjust the flow with it. In this construction, a plate or wedge is used. The scheme of work is simple: you need to move the lever, raise or lower the wedge or plate that covers the inner diameter of the pipe. It is justified in the case when it is necessary to close the flow of water very quickly. In fact, this device is not suitable for everyday use, but is used as an emergency shut-off element.
The crane structure includes a molded body( cast iron, brass) and a shut-off and regulating element, represented as a rotating body. In this body, a special hole is made, the axis of which can coincide or not coincide with the direction of movement of the liquid. If it is the same, the tap does not interfere with the movement of water, if not - on the contrary. Such an armature is used to turn the flow on and off at the point of consumption.
Standard installation of water fittings. Nuances when installing
Mounting the valves on the water pipe is done in many ways, depending on whether you need to repair the device or replace it quickly.
Apply two technologies. The first is assembling the assembly onto a threaded pair( tighten the locknut).The second is the assembly of the assembly on the flange connection( fix with bolts).These two types depend on the pipeline, the former being used for low and medium pressure pipelines( from 1 to 100 atmospheres), and the second for high( more than one hundred atmospheres).
Screw mounting is as follows: screwed nuts are tightened on the threaded sleeves of the pipes, after which the drivings are screwed into the body of the locking device. The installation site should be sealed with a special tape or a pack( organic seal).After the pipes are screwed in, an additional layer of special sealant is wound between the end face of the body and the lock nut.
Flange mounting is used only when special rings are installed at the ends of the pipe and housing. At the same time, they must be put into the case at the design stage of the device. The flange ring is mounted on the end of the pipe by arc welding. When the flanges are equipped, a special gasket is installed between them and the pipe and the flanges are tightened with mounting bolts. A similar operation is done on the other side. This installation is quite simple. The operation provides a hermetic and high-strength connection of the valve body and pipe.
