What is the common fault of pneumatic film regulating valve?

Leakage is the easiest failure of regulating valve during operation. Some leak at the welding place, and some leak at the sealing place of the stuffing. When leakage occurs at the welding site, repair welding can be done during overhaul; when leakage occurs at the sealing site of the stuffing, new stuffing can be replaced. Sometimes the film of the film actuator is damaged, and the valve stem can't act normally with the air pressure signal, so it needs to be replaced with a new film.
In order to avoid the deformation of the valve stem affecting the regulating function, it is better to stand on the pipeline when installing the regulating valve. It is not suitable to install the low-temperature film regulating valve horizontally, and it should form an angle above 150 with the level so that the sealing place of the stuffing is not affected by the liquid. The slanting valve must be lifted.
When operating, always pay attention to whether the regulating valve gets stuck. The sealing filler should not be screwed too tightly in case of affecting the movement of the valve stem. When the adjusting range of the regulating valve is not enough, bypass valve can be added beside the regulating valve to enlarge the adjusting range, or the regulating valve with large range can be used instead.