Valve flow medium

Medium flows through the valve pressure loss (both before and after the valve pressure difference), which is a certain resistance valve on the flow of the medium, the medium, it takes some energy to overcome the resistance of the valve. Conservation of energy considerations, the design and manufacture of valves, as much as possible to reduce the resistance of the valve on the flow medium.
Hoisting hoisting force and torque pneumatic hand valve
The opening and closing force and closing torque is on or off valve must be imposed by force or torque. When the valve is closed, you need to make a certain sealing pressure than the sealing surface between the opening and closing parts Berenices, but also to overcome between the stem and the packing between the stem and the nut thread at the stem end bearing and other friction parts of friction, and therefore must apply the closing force and closing torque, the valve opening and closing process, the need to stop force and the opening and closing moments of change, and its maximum is close the final instant or open the initial transient. Design and manufacture of valves should strive to reduce the closing force and closing torque.steam solenoid valves