<http://webisa.webdatacommons.org/81457164>	<http://www.w3.org/ns/prov#value>	"Slips are the most integral part of the wellhead; they hold the casing or tubing to ensure a good grip on the pipe." .
<http://webisa.webdatacommons.org/prov/176088150>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/81457164> .
<http://webisa.webdatacommons.org/81457164>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<lowerywellhead.com> .
<http://webisa.webdatacommons.org/81457164>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .