If it is found during commissioning that the manufacturer of pneumatic butterfly valve is very slow in opening the valve at the initial position, but it will be very fast after the action. If it is found during commissioning that the valve is very slow in opening the valve at the initial position, but it will be very fast after the action, this situation is that the valve is closed too tightly, Just turn down the stroke of the cylinder a little (turn the stroke adjusting screws at both ends of the cylinder a little inward at the same time, and when adjusting, move the valve to the open position, and then turn off the air source and adjust it again), until the valve can be opened easily and closed in place without leakage.

Stability of non-metallic contraction joint and its manufacturing method
During the normal operation of non-metallic contraction joints, the gravity of the pipe system is required to be borne by various supports and hangers, so that the pipe system can freely shrink (contract); Tongjing often uses the pre deformation of the pipeline to reduce the thrust of the pipe support and strengthen its stability, which are particularly important in the process of installation, new construction and reconstruction.
During the normal operation of non-metallic contraction joints, the gravity of the pipe system is required to be borne by various pipe supports (hangers). The mass of the corresponding flue for this installation is 20t, which is borne by a constant force spring. In the process of transformation, the rigid fixation of the pipeline system was stopped, but the reset of the constant force spring was not stopped; Due to the particularity of the displacement of the constant force spring, when the external load is removed, it cannot return to the original state. Therefore, after re installation, the constant force spring is in a state of no force in practice; When the rigid fixation is removed, the mass of the flue is pressed down to form the downward movement of the pipeline.