About: http://webisa.webdatacommons.org/455865241

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	To control corrosion or contamination, especially for the aluminum tubing, the inner space between the tubing and the casing can pressurized with nitrogen to prevent ingress of fluids.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com