About: http://webisa.webdatacommons.org/391615161

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Such a valve or other flow restrictor is useful during the fracturing process to control any pressurized production fluids that occur during the fracturing process.
http://www.w3.org/ns/prov#wasQuotedFrom	freepatentsonline.com