The autonomous water supply system of country houses includes not only pumps and piping. Additionally, the water supply is equipped with protective pipe fittings, a striking representative of which is a check valve for the pumping station.
Types and purpose of the check valve
The main purpose of the valve is to maintain the pressure inside the water supply network in optimal mode. In particular, his task is to prevent the water that the pump has pumped into the pipeline from spilling back.
This type of shutoff valves is divided into two types:
- Bottom valve. Install in front of a pump that pumps water from a well or well. The device is located in water.
- Trunk. Insert a water pipe before or after the pump.
There is a classification of valves, which are based on the purely design features of the device. The main difference is the form and principle of the working body.
Bottom valve
Bottom valves on the market are represented by two modifications. Spring loaded option - a cylindrical-shaped device with a disk inside. It is supported by a spring on top. On the reverse side, the disk abuts against the saddle — an opening formed by a protruding edge located along the inside diameter of the device.
When water is injected, its pressure rises, which from below presses on the disk. The spring is compressed, the disk opens a gap between itself and the saddle. As soon as the pressure decreases, that is, the pump stops pumping water, the spring opens and presses the disk to the edges of the seat.
The second modification is casement. Inside the disk-shaped device is one or two wings. They open under the pressure of the water coming from below, and close when the pressure drops to zero. The flaps themselves are attached to the inner surface of the valve with devices that resemble door hinges. In this case, the valves are precisely adjusted to the size of the saddle to avoid leakage of fluid from the pipe.
According to the method of fastening, both bottom valves are divided into two groups, which are based on the method of fastening the device to a pipe or pump. The connection is made by thread or using flanges. In domestic pump installations, a threaded connection is used.
A strainer must be installed in front of the bottom valve. The device itself is mounted in the direction indicated by the arrow on the device. The distance from the non-return valve to the bottom of the well or well should not be less than 0.5 m, to the water mirror not less than 0.3 m.
Speaking about the place of installation of the non-return valve on the submersible pump, it is necessary to indicate that there are pump installations on the market, inside which a strainer is already installed. Therefore, the filter element is not mounted in front of the valve. Pipe fittings are often installed after the pump.
Trunk
In this category there are several types of check valves, which differ from each other by a locking device and the principle of its operation. But the purpose of the devices is one - to ensure the movement of fluid in one direction and to prevent the formation of reverse current. The working body (locking device) opens under the action of moving water and closes more often under the action of its own weight or spring.
The locking element in the design of the non-return valve can move horizontally (along the axis of movement of water), vertically (perpendicular to the water flow) or at an angle. When mounting the device, it is necessary to monitor not only the correct location of the arrow on the case, but also the location of the cover.Manufacturers offer four types of check valves, characterized by the operation of the shut-off element.
Spring loaded the device is a valve design in which the valve moves vertically. At the same time, it is spring-loaded from above, therefore it works as a spring bottom element.
Swivel A model is a structure in which a locking device moves in the direction of water movement. This is a disk located vertically and attached to the edge of the saddle hinges. In this case, the disk opens up and falls under the action of its own weight.
Disk option - a cylindrical-shaped device, inside of which a vertical disk is installed. On the one hand, it is spring loaded. The locking device moves in the direction of movement of the water.
Ball a model is an angular type construction that is installed only on a vertical pipeline. Such a check valve is similar to a tee, the outlet of which is tightly closed. It is in it that the ball mixes. When the pump does not work, the ball is located at the bottom of the structure. The pressure begins to increase, water presses on the ball from below, and the ball moves to the outlet of the device, opening the main line. As soon as the pressure drops, the ball rolls back to its place along the inclined plane of the outlet, blocking the cross section of the water main.
In the construction of low-power autonomous water supply systems, which are most often organized in suburban areas, a ball or rotary model is usually used. They have small overall dimensions due to the lack of a spring and the long stroke of the locking device.
The main non-return valves to the pipes of the autonomous water supply network can be mounted in four ways. Each has its own advantages and disadvantages.
- Coupling - devices with internal thread on each side.
- Flanged - on the nozzles have flanges that connect with mating elements welded to the water pipe.
- Wafer - disk type models that are mounted between the pipe flanges and fastened to them by four studs, i.e. the valve is clamped by flanges.
- Fatty - with the help of electric welding, they are directly attached to the pipes of the water supply network.
In domestic autonomous water supply systems, mainly check valves are used. They are easier to mount and dismantle. Repair of this device is quite simple.
Production material
The market of water fittings offers a fairly wide selection of check valves in terms of the material from which they are made. The main requirement is high strength and corrosion resistance:
- cast iron;
- stainless steel;
- bronze;
- brass;
- plastic.
The ideal option is stainless steel. But products from it are expensive. Cast iron models are the most bulky. In domestic networks, they are practically not used. The most popular are brass. These valves do not corrode under the influence of water, the price is reasonable. Plastic also does not corrode, but experts recommend installing them on pressure pipelines with low pressure.
Locking devices are made of stainless steel, plastic or aluminum. In spring-type valves, the most vulnerable unit is the spring. It most often fails, so in almost all devices a stainless steel part is installed.
Today, many manufacturers are trying to reduce the cost of their products to make them competitive. Therefore, in the market you can find combined models. For example, a brass valve with a locking device made of stainless steel or plastic. All valves are tested and tested for tightness of the structure, which is confirmed by certificates, so the combined modifications comply with the standards and requirements of GOST.
Mounting Features
Installation conditions for check valves are the same as for other types of valves.The main requirement is to install correctly so that the arrow on the device’s body is in the direction of the water flow. Other conditions:
- easy access to the valve for maintenance and repair;
- Strictly ensure that the devices are installed horizontally or vertically;
- the check valve for the well must be equipped with a filter.
A valve in an autonomous water supply system plays an important role. With it, the pump remains full all the time, there is no need to fill it at startup. This increases the usability of the water supply network.
