GB/T 12221-2005 Translated English of Chinese Standard. (GBT 12221-2005, GB/T12221-2005, GBT12221-2005): Metal valves - Face to face, end to end, center to face and center to end dimensions [Buy--download True-PDF in 3-second: https://play.google.com/books > Sign in > This BOOK > "3-dots" > Export > Save as "*.pdf"]