There are several companies that manufacture similar models of valves such as valve KEE; homines valve; METSO company
Currently most of the designs are specified with ball valves, in many cases is due to its operation is simpler than the wedge plug valve or switch, in both valves is essential for the proper operation keep a good injection of the steam purge
in these directions you find information that can help you
http://www.osha.gov/dts/shib/shib082903c.html
http://www.velan.com/velan/en/industries_served?id=131
WWW.epa.gov/emergencies/docs/chem/delayed_coker.pdf –
