About: http://webisa.webdatacommons.org/33931476

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	By forming the tube seat from (or lining the tube seat with) a hard material, preferably a material harder than the needle or other access device which is to be used, the likelihood of damage to the valve can be greatly reduced.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com