The size of the drive device and the butterfly valve connection flange is specified by GB / T12223.
For the stainless steel butterfly valve for handwheel (including the handwheel including the drive) or the wrench, except for the order contract, when the handwheel or wrench is opposite, the handwheel or the wrench valve should be turned off.
The edge of the handwheel or the word "open", "off". There should be obvious arrows and "off" words in the closing direction of the butterfly plate, or mark the two-way arrows.
When the stainless steel butterfly valve operating in the handle is fully opened, the handle should be parallel to the pipeline axis.
All stainless steel butterfly valves should have an indication mechanism that represents its position and a limit mechanism that ensures the full open and all positions.
The stainless steel butterfly valve of the wrench should have at least three different opening locking mechanisms.
