US Patent 10260651 Butterfly valve formed of a laminated material

A butterfly valve includes a valve body-side valve seat section, a valve box-side valve seat section, and a valve movement mechanism. The valve movement mechanism includes a cam groove, a cam projection, and a reverse key. The valve movement mechanism moves the valve body in an extending direction of the flow passage along with rotation of the valve shaft between a blocking position and an open position. One of the valve body-side valve seat section and the valve box-side valve seat section is formed of a laminated material composed of alternatingly stacked plates made of metal and plates made of expanded graphite.