Shut-off valves in modern water supply systems

The plumbing system of a residential building has a significant number of valves available along the water pipes. They provide emergency shut-off of water during repair work or replacement of communications. To turn off the water, first of all it is necessary to detect and close the shut-off valves.

The place of shut-off valves in the municipal water supply system

The shut-off valve system includes:

• The main valve, which is located at the inlet, next to the water meter;
• Local valves located near points of direct consumption – boilers, faucets, toilets, etc.

Valves usually work in one of two ways: either the solid inner part rotates to open and close the running water, or some kind of stem seals the seat with a washer or seal to block the flow of water.

Types of shut-off valves

In modern domestic water supply systems , three types of shut - off valves are used:

• Ball bearings.
• Rotary.
• Latches.

Ball bearings

The ball valve is quite large and is usually located next to the lever handle. With its help, it is possible to quickly control the water flow. This will require a small (quarter turn) movement of the handle. This design of the valve is often used for emergency shut-off of water supply to the house. Such a valve is easily recognized by its appearance: the valve body under the handle always has a convex section where the ball enters from the inside. A through axial hole is provided in this inner ball. When the valve is open, the hole is aligned in the water pipe, allowing the flow of water to move in the desired direction. When the handle is closed, the ball rotates 90°, so its hole is blocked.

Ball valves are becoming increasingly common in main water supply systems.

Gate valves

The valve regulates the flow of water by means of a rotary handle: it is rotated by raising or lowering the stem over the valve seat. When the rod is pressed, the access of water to the point of its distribution stops.

Both the ball valve and the gate valve are devices that work on the principle of "all or nothing", the fundamental difference is only in the dimensions – the gate valve is larger. Therefore, in municipal plumbing valves are less common, and are more typical for industrial water supply systems. But on the pipes leading, for example, to a hot water boiler, it is the valves that are installed that are able to control large water consumption, and are insensitive to its mechanical contamination.

Rotary

The rotary valve is a type of shut-off valve that allows you to adjust the water flow. Inside the valve there is a partition with a passage for water flow. The handle controls the piston with a sealing washer – when the handle closes the valve, the piston moves down to the water flow hole and partially closes it. By controlling the handle, you can feel the movement of the internal plunger. when it is tightened inside the valve. Despite a slight increase in the time required for opening, this type of shut-off valve is widely used to control the flow of water in pipes leading to the corresponding water pipes.