Each of us faces cranes or valves which blocks the water in our "penates". In this photo (below), you see valves and ball valves, all this economy is located in the basement of an ordinary high-rise building.
Why, the valve is still used in water supply, it is difficult for me to understand. And the fact is that they have outlived their time and should not be used in heating and water supply systems.
Why, you ask? Look at the picture below:
Red arrows indicate the movement of water; it has to overcome the additional resistance of this shut-off valve when the stem is open. Due to the additional obstacle (partitions) to the movement of the liquid, there is a pressure drop at the consumer.
YES, not much. But globally, house, microdistrict, city. Then the pumped pressure in the water supply system drops significantly. And this is additional costs for electricity and additional load on pumping equipment. As a result, it is included in the tariffs.
In addition, the valves have not a very good design feature, leakage from under the stuffing box packing, which requires additional attention and requires maintenance.
30 years ago, the USSR has already begun to produce Ball Valves. They were very good substitutes. valves.
Their huge, positive feature is full permeability, that is, the minimum resistance to the flow of fluid.
In addition, they practically do not require attention or maintenance. In the price category, Ball Valves not much more expensive valve or even cheaper in some cases.
The only advantage of valves is the ability to repair them (replacement of gaskets and stuffing box packing) without removing them from the pipe. Otherwise, only ball valves of good quality win.
Why stop valves in the form valves still has not completely outlived itself, for 30 years, I do not understand all the advantages ball valves on the face, and we, the housing and communal services system, still cannot get rid of the legacy of the last century ...