float valves
Very often, a water tank has a device such as a float valve, which is easy to use. With it, the water supply automatically turns on and then off. But if a float valve is selected for a tank, you need to find out for which capacity it is intended.
Why is a float valve needed?
Why use a float valve for a water tank? The answer to this question is very simple - not to add it yourself, as it is inconvenient, tedious, and not everyone has the patience.
But if there is a float valve for water in the tank, the whole problem is immediately solved
It is important to consider that it will be needed in different containers, both small ones like a purifier or toilet bowl, and large barrels used for watering plants in the garden
Such a mechanism is installed so that there is no overflow of water. First, water is saved. And secondly, there will be no flooding of the room.
And when the tank is filled to a certain level, the water supply is shut off. And then the float valve for the tank drops if the water from the tank begins to decrease.
It should be noted that all float valves operate in automatic mode. You just need to set them up in such a way that they cut off the water supply at some point.
Any float valve for water tanks is configured in such a way that it can work even with a minimum water pressure of 0.6 bar.
Varieties of float valves
When choosing a water level float valve, you need to pay attention to both its design and other features. Such a locking mechanism has the following characteristics:
- construction;
- float size;
- material of manufacture;
- installation method;
- threaded connection pipe;
- device type.
The most commonly used mechanical float valves, which are more suitable for domestic conditions. For example, they are found in toilet cisterns. But in some cases, an electric float valve is used, where the speed of water intake from the tank plays an important role.
If we are talking about watering a garden or vegetable garden, you need to buy not one float valve for a large capacity, but two. One must be electrical and the other mechanical.
This is especially important if the solenoid valve fails. In this case, the mechanical plastic float valve will be able to shut off the water supply.
By the way, plastic valves are more practical and durable. Sometimes on sale you can also find a rubber pear. But this material is not as durable as plastic.
They also differ in their productivity - 1/2 ″ and 3/4 ″ - 4.7 m3 / hour 2 ″ - 64 m3 / hour. This indicator must be taken into account when choosing such a locking device.
Principle of operation
Gasoline vapors formed in the tank rise up and through the hole at the tank neck first enter the separator. There they condense and merge back into the tank. That part of them, which does not have time to turn into condensate, through the gravitational valve through the steam pipeline, they fall directly into the absorber, where they are absorbed by activated carbon. This happens when the engine is not running. 
Otherwise, while the car is moving, when the engine is warm, the control system opens the solenoid valve, and the absorber is purged. Gasoline vapors, together with the air that has entered through another valve, are blown into the engine intake pipe, where they are burned.
It's kind of a double effect.
- firstly, the atmosphere is not polluted by unnecessary, harmful fumes;
- secondly, we have, albeit small, but fuel economy.After all, if there were no absorber, the fuel would simply simply evaporate.
In a word, everything was prescribed as an ecologist, everyone is fine, everyone is happy.
Absorber failure
Over time, the absorber becomes clogged and may become unusable. Signs of a malfunction of this element of the fuel system can be determined by indirect signs. One of them is the formation of excess pressure in the fuel tank. This happens due to the formation of vapors that have nowhere to go from the gas tank. In this case, at the moment of unscrewing the cover, you will hear a hiss.
On my VAZ 2112, it was worth starting to unscrew the tank cap, and it was kicked out with such force that it’s scary to imagine. I would like to know then that this is a problem with the absorber. And so I had to just let off steam several times a day. Also, due to the poor performance of the absorber, the speed of the car, at idle, may begin to “float”. 
In our country, the problem of defective parts is solved very simply, especially those without which the car can drive. Shoot and go further with one voice, the craftsmen advise. Here, of course, it's up to you to decide, but something tells me that you and I breathe this same air. And if everyone without exception takes and removes all the “extra” eco-details, since they are not really needed in the car, then one “beautiful” day there will be nothing to breathe.
Replacing this part will take no more than 15 minutes, this can be done:
- on one's own;
- contacting a car service.
