Pneumatic butterfly valves are usually not allowed to adjust and throttle.

Pneumatic butterfly valves can only be fully opened or closed, and regulation and throttling are usually not allowed. When the wrench is parallel to the channel, the pneumatic butterfly valve of the wrench opens completely. When the wrench rotates 90 degrees, the pneumatic butterfly valve of the wrench closes completely; the valve stem of the pneumatic butterfly valve is insensitive.
Loosen the cover bolt, evenly loosen the expenditure to support the connecting nut or thicken the washer, in order to reduce the preload, pay attention not to leakage; packaging leakage. Tighten cap bolts or replace fillers (1 filler, 2 fillers, 1 filler). When installing pneumatic butterfly valve, be careful not to trim and tighten the cover bolt evenly; the right valve body and the left valve body leak. Trim the sealing surface, remove dirt, replace the washer, and tighten the nut evenly.
Pneumatic butterfly valve seal leakage. Cross-tighten coupling nuts evenly, increase preload, or adjust seats, gaskets and clean sealing grooves; do not put auxiliary rods or other things on wrenches when not tightening pneumatic butterfly valves, otherwise the stem will be damaged.

If the operation of pneumatic butterfly valves is intense, the closure of some pneumatic butterfly valves is difficult to open due to thermal expansion. At this point, the cap bolt can be loosened and the stem can be removed after the stress is removed. When the packing is too tight, the packing can be relaxed properly.