These valves are used more often in places where they want to completely open and close the flow of fluid. The properties of these valves are due to the low pressure drop across the pipe, which is why the valves are used for long pipes.
When the drain completely drains out of the flow path of the fluid and thus has no resistance to flow, but if the drawer is directed to its lowest point, the fluid will cause a change of direction and collision with the drawer. Turbulence and loss of pressure. In plumbing, pipes and valves are often interconnected (by welding or by screwing), but in general, the connection of the valve and the pipe is done by the flange and the bolts and nuts, and in order to prevent the leakage between the flange pipe, the sealing valve or gasket Gets