To change the flow rate of transported media to a complete stop, a water supply system is used for water, which has the following properties:
- simplicity of design and operation;
- application at high pressure drops;
- small size and weight;
- possibility of installation on any section of the pipeline;
- a small shutter stroke ensures convenient maintenance.
Valve types
It is classified according to three criteria:
- body shape;
- type of locking part;
- installation method in the system.
Valves are classified according to their body shape as follows:
- direct-flow - the flow is blocked by the valve seat in the transverse direction;
- angular - the locking element moves towards the movement of the medium;
- mixing - to obtain a given water temperature.
The locking element differs in design:
- Ball - a through sphere in a straight-through body. When the longitudinal axes of the hole and the body are aligned, the flow movement is completely opened. Turning in the perpendicular direction 100% shuts off the flow of fluid. The valve performs the function of only a locking element, and it is not suitable for regulation. The use of the device is associated with its high reliability, speed of shutting off the flow and compactness. Almost nothing breaks in it, since there are very few parts.
- Valve - with a constipation associated with a threaded rod screwed into the seat nut. The unit is used to control the flow and to completely shut off the flow (in the lowest position).
- Needle - conical piston with high pressure fluid flow control (about 220 bar).
Valve materials:
- ball: brass, stainless or;
- valves: cast iron, brass.
New materials are also being used to make valves. The polypropylene body makes the device durable and cheap at the same time. Fluoroplastic coatings improve resistance to corrosion and aggressive environments.
The difference between a faucet and a faucet
Water faucets and valves differ, although they are often identified. The latter is installed between the joints of two pipes, forming a line. The faucet includes a faucet and a spout through which water flows out.
The device and operation of the valve valve
The most important working body of the valve is the seat with the valve manually moved by a spindle. The water valve valve, the device of which is given below, contains a thread in the body and on the stem, which has the property of braking. As a result, the valve disc is pressed tightly against the seat, shutting off flow when the valve is closed. In the open state, the flow area remains unchanged during the movement of the water flow.
Usually, the body is not threaded, as it wears out quickly. To do this, a running nut is attached to it, into which the spindle is screwed. Then, instead of a worn-out node, you can install another one, while the body will remain. All parts are interchangeable with a water valve (GOST 12.2.063-81, GOST 5761-74).
The valve is opened by turning the handle. In this case, the spindle moves forward, freeing the passage for the liquid. If the rotation is reversed, the valve will close.
The device is connected to the pipeline through the inlet and outlet pipes. They can be distinguished from each other by the presence of an arrow indicating the direction of flow.
Angle valves
For a perpendicular change in the direction of fluid transfer with the possibility of overlapping and adjustment, an angled water valve is used (drawing below: a - through passage; b - angular).
The perpendicular arrangement of the inlet and outlet nozzles determines the purpose of the valve for pipelines that change direction by 90 °. The principle of its operation is the same as that of the through passage. The shutter stroke is made coaxially with the inlet pipe.
Scope of application of angle valves:
- When pipes are connected to a heating radiator, when it is blocked or regulated by a water supply valve (see photo below). Models made of high-temperature polypropylene are more convenient and cheaper than brass ones when connected to plastic pipes.
- Prevention of vibration and buildup of pipelines.
- Decreased fluid flow rate without high frequency noise.
- In operation in any position.
- Simplified installation of pipes by reducing the consumption of fittings.
The device and principle of operation of the ball valve
The main working body of the valve is a ball with a through hole. When the handle is positioned along the pipe, the valve is open. If it is turned perpendicular to the pipe, it will close. The hole in the ball can be round, square, in the form of a trapezoid or an oval. In valves of small diameter, the valve is made floating, and for large-sized devices it is made on special supports. High tightness of the shutter is provided by an elastic seal. This allows you to install this type of models on gas pipelines.
The water ball valve operates in two extreme positions when rotated 90 degrees, when it is fully open or closed. Attempting to control flow will result in rapid seal wear.
They have wider possibilities for connecting pipes when installing water supply systems:
- walk-throughs;
- corner;
- with three or more outlets in order to redirect transported flows.
Connections with pipes are made by fitting, flanged and welded. The latter option allows you to permanently install a water valve in the system.
Shower faucets
The device is made as a single-lever ball or in the form of two valve valves. The kit includes a replacement shower head with attached flexible hose and bath spout. The mixer is made hidden, bringing out only the valves for controlling the water temperature.
The classic option is a two-valve accessory with manual temperature control. Cold and hot water are mixed in a special chamber, and then flow into the shower hose or spout. The main elements of the device are two crane boxes with replaceable gaskets.
A single-lever device with convenient water regulation is becoming popular. The main element of the mixer is a replaceable cartridge. In case of failure, it can be easily removed and replaced with a new one.
With a built-in thermostat, adjustment is simplified. It is pre-configured, which guarantees the output of water at a given temperature. To do this, there is a thermostatic element in the housing that distributes the flows. The only drawback of such models is the high price.
Installation
Small diameter valves are threaded (up to 60 mm). There is a drive on the pipe, the connection is sealed with hemp or fluoroplastic film. Winding is carried out in the direction of thread twisting. This creates a tight connection that can withstand high pressure.
The large diameter pipe is connected by a flange to the washer of a straight or angle valve through a sealing gasket. They are fastened together with bolts and nuts. The connection of the flange with the pipe is carried out by arc welding.
Water valve: repair
If the shut-off element of the valve is damaged, it is replaced with a similar, unworn or new assembly. To do this, the pipeline section is freed from liquid, blocking it from both sides. Then the valve-type shut-off element is dismantled. The ball valve is removed completely open-ended or On the flanges, the nuts are twisted in parallel and gradually - 3-4 turns on each.
First, you should check the health of the seals, which are replaced when worn. Most leaks are caused by deformation of the gaskets and stripped threads due to improper installation. Then the body and seat are inspected. In the absence of cracks, the assembly is assembled again. The case cannot be repaired if mechanical damage appears on it. Growth to the pipeline requires its cutting and the need for further welding.
In this case, you will have to install a new or repaired water valve. An unprepared person should not undertake complex repairs because of ignorance of its features.
Shut-off valves create additional resistance, so blockages can form at the joints. It is not always necessary to remove the valves. Sometimes it is enough just to flush the pipelines by opening all the taps.
Replacing the oil seal can be done carefully with your own hands. To do this, turn off the water supply from the riser, disassemble the locking mechanism, replace the gaskets and lubricate the moving parts.
Conclusion
The water valve is easy to operate and does not require special maintenance. Each model should be used for its intended purpose. A simple repair of the valve can be done by hand, if you act carefully and correctly.
