The check valve is used to prevent the reverse flow of the medium. It opens by itself using the kinetic energy of the fluid itself, and automatically closes when it flows in the opposite direction. It is always installed at the outlet of the pump, the outlet of the trap, and other places where the reverse flow of the fluid is not allowed. Check valves are divided into three types: rotary type, lift type and opposite type. In the rotary check valve, when the fluid flows only from left to right, if it flows in the opposite direction, it will automatically close. In the lift check valve, when the fluid flows from left to right, the valve body rises to form a passage, and when the fluid flows in the opposite direction, the valve body is pressed against the valve seat to close. In the opposed check valve, when the fluid flows from left to right, the valve body opens to form a passage, and when the fluid flows in the opposite direction, the valve body is pressed against the valve seat to close. The opposed check valve can be installed in multiple positions, which is small and light. A compact valve.
The differential pressure between the front and rear of the regulating valve is constant. If the opening degree of ordinary valves changes within a wide range, the flow rate will not change much, but when it reaches a certain opening degree, the flow rate will change sharply, that is, the adjustment performance is poor. The regulating valve can change the stroke of the valve body and the resistance number of the valve according to the direction and size of the signal, so as to achieve the purpose of regulating the flow of the valve. Control valves are divided into manual control valves and automatic control valves, but there are many types of manual or automatic control valves, and their adjustment performance is also different. Automatic control valves include self-operated flow control valves and self-operated differential pressure control valves.
