The pneumatic butterfly valve is composed of pneumatic actuator and butterfly valve. Pneumatic butterfly valve is used to start and close with the circular butterfly plate which rotates with the valve stem, so as to achieve the actuating action of pneumatic valve, which is mainly used as a cut-off valve, and can also be designed as a function of adjusting or adjusting valve. At present, butterfly valves are used more and more in low pressure and large diameter pipelines.

Working principle of pneumatic butterfly valve

The butterfly plate of the butterfly valve is installed in the diameter of the pipe. In the cylindrical channel of butterfly valve body, the disc shaped butterfly plate revolves around the axis, the rotation angle is 0 degrees -90 degrees, when the rotation is 90 degrees, the valve is in the full open state. The butterfly valve is simple in structure, small in size and light in weight, and consists of only a few parts. The valve can be opened and closed quickly with only 90 degrees of rotation, and the valve has good fluid control characteristics. When the butterfly valve is fully open, the thickness of the butterfly plate is the only resistance of the medium flowing through the valve body, so the pressure drop produced by the valve is very small, so it has better flow control characteristics. The butterfly valve has two seal types, which are elastic seal and metal seal. Elastic sealing valve, the seal ring can be inlaid on the valve body or attached to the circumference of the butterfly plate.

Maintenance and debugging of pneumatic butterfly valve

1, cylinder inspection and maintenance plan

Usually, clean the cylinder surface and fill the cylinder shaft, and open the cylinder cover at regular intervals every 6 months to check whether there are any sundries and moisture in the cylinder, as well as the grease status. If the grease is short or dry, the cylinder should be dismantled and the grease is added after full maintenance and cleaning.

2, valve body inspection

Every 6 months, check whether the appearance of valve is good and whether the flange is leaked. If it is convenient to check whether the valve body seal is good, no wear, and whether the valve plate operates flexibly, whether the valve has foreign bodies stuck.

Cylinder body disassembly and assembly methods and matters of attention

The cylinder is removed from the body, the ends of the cylinder cover apart, remove the piston must pay attention to the direction of the rack piston, and then use a force clockwise rotation axis of the cylinder so that the piston runs to the outside, and then close the valve hole with ventilation pressure will slowly gently piston, but this method must pay attention to slowly ventilation, otherwise the piston will suddenly ejected, a little dangerous! Then the cylinder shaft circlip down the axis of the cylinder can take out from the other end. Then, each component can be cleaned and grease added. The grease parts should be: inner wall of cylinder and piston seal, rack and back ring, gear shaft and seal ring. With good lubricating grease after the demolition of the site according to the order and reverse order according to the order of the installation after the demolition of the site and the reverse order of installation, attention must be paid to the gear rack position, we must ensure that in the open valve position when the piston retracts into the most inside position when the gear shaft groove and the block parallel. Close the valve position is extended to the outside of the piston position gear shaft and the cylinder body vertical groove.

Installation and debugging methods of cylinder and valve body and matters of attention

The valve with a force placed in the closed state, the valve with external force in a closing state, the clockwise rotation of the valve shaft until the valve plate and valve seat sealing contact, while the cylinder is placed in the closed valve state (i.e., the axis of the cylinder and the cylinder form above the slot vertically for clockwise rotation of the valve, then close the valve) the cylinder attached to the valve (up and valve mounting direction parallel or vertical, can look at the screw holes) on it, there is not much deviation, if there is a little deviation, the cylinder body to rotate it, then screw fastening. Pneumatic butterfly valve check valve installation debugging accessories are complete, solenoid valve and silencer, if not complete, not for debugging, normal pressure is 0.6MPA + 0.05MPA, before the operation to ensure that the valve body without debris stuck in the valve plate, with manually operated solenoid valve manual button for the first time when debugging (manual operation the solenoid valve coil power, manual operation is effective; electronic control operation manual twist placed 0 ring out of power, the manual operation is effective; 0 is off valve 1 to open the valve, the electric valve, power off valve for electric valve, power off the open position the valve solenoid valve coil is rotated 180 degrees), and can be installed to observe the operation state of the valve.

If in the process of debugging operation found in pneumatic valve manufacturers in the open valve the starting position is very slow, but as long as the action soon after, during the test run that the valve in the open valve when the starting position is very slow, but as long as the action quickly, this is the valve closed tight, only the cylinder stroke adjustable a can (the ends of the cylinder stroke adjustment screw to adjust at the same time point, to adjust the valve operation to open position, and then turn off the gas valve open, to reset) easily, no leakage on the line closed in place. If muffler is adjustable and muffled, it can regulate the switching speed of valve. It is necessary to adjust the muffler to a suitable opening of valve switch, if it is too small, it may make the valve do not move.