Like many others, I used to think that any tap would work to regulate the water flow (in a water supply or heating system). Turns out I was wrong. When using a ball valve for such purposes, it will soon break. I'll tell you more.
In the list of shut-off valves that are installed on water pipes or heating systems, ball valves occupy a leading position. I will assume that every second inhabitant of our country has such a tap in the apartment (perhaps more than one).
Are they suitable for flow control? What happens when the water pressure decreases? Can ball valves be left ajar? All this will be discussed below.
What type of valves are ball valves: control or shut-off valves?
Many cranes of this type, which are offered to us by domestic manufacturers, are of the shut-off type. This means that they only have two working positions: open and closed. This is explained by the direct design of the crane.
In the case (in the figure position 2) is a solid shutter (position 1
). With its help, the water flow is either blocked or opened. In order for the fittings to be completely sealed, an O-ring made of fluoroplastic (position 3). In the closed position, the ring is firmly pressed against the body by means of a ball. Therefore, the risk of leaks is minimal.When the tap is open, the PTFE ring retains its original condition and does not wear out. Note that in the closed position, the ring is also not subject to wear, since the liquid does not circulate.
If you leave the tap in an intermediate position (for a thin stream), water will flow through the ring, which will quickly become unusable. This is especially true for regions with hard water, which contains all kinds of impurities.
When you want to close the valve completely, the build-up will prevent an absolute seal from being achieved. This is why manufacturers strongly advise against using ball valves to regulate water flow.
Let me summarize! Ball valves are shut-off valves. Therefore, do not use them for adjustment. Otherwise, the structure will simply fail.