The grooved gate valve is differentiated according to the setting position of the drive thread of the valve stem. There are two kinds of upper thread and lower thread. The upper thread means that the drive thread of the valve stem is arranged outside the valve cover, and the lower thread means that the drive thread of the valve stem is arranged inside the body cavity. There are two methods for the lower thread: bright rod and dark rod: the former is the valve stem nut on the bonnet or bracket. When opening and closing the valve, the valve stem is lifted by rotating the stem nut; the latter is the valve stem nut Direct contact with the medium inside the valve, when opening and closing the valve, the valve stem is rotated to complete.
The parts of the grooved gate valve must go through the following processes before assembling: According to the processing requirements, some parts need to be polished, and the appearance must not have processing burrs, etc.; all parts are degreasing treatment; after degreasing is completed, pickling passivation , The cleaning agent does not contain phosphorus; after pickling and purification, rinse with pure water to clean, there should be no residual agent, carbon steel parts omit this process.
Use non-woven cloth to dry the parts one by one. Do not allow the appearance of the remaining parts such as wire lint, or dry it with clean nitrogen; use non-woven cloth or fine filter paper with pure alcohol to wipe each part until there is no Dirty color. The parts of the gate valve for cleaning the clean groove must be sealed and stored for installation. The basic operation of the grooved gate valve: the gate valve with bypass should be opened before opening.
During operation, the human body cannot face the top of the valve stem directly to prevent the valve stem from spraying out and hurting people. The switch operation should be stable and even force biting. The use of impact force is prohibited. It can be operated by hand under normal conditions to prevent the use of machining levers to operate the new valve. The strength of the handwheel is planned based on the torque required for operation. Therefore, it is not allowed to use the handwheel as an operating pedal and to add or socket extension levers arbitrarily, and it is not allowed to use ropes and other effects on the handwheel, and then crane or Pulleys to operate or lift the valve.
For gate valves with a hand wheel or handle, roll the hand wheel clockwise to close, and roll counterclockwise to open. When the valve is fully opened, the handwheel should be reversed 1-2 turns. The operation method of gate valves with other actuators should strictly follow the product manual. Under high pressure difference, the gate is easily damaged when the gate is half-open and half-closed. Therefore, the gate valve cannot be used for saving or conditioning. It is necessary to completely open or close it all at once.