wherein {HEAD ~ the annular surface} has {TAIL ~ a radially inner portion} and a radially outer portion, and said continuous seal is located at least on said radially outer portion, while the radially inner portion allows the seal of the valve to be brought into sealing engagement with the tubular body 
has
wherein { HEAD ~ the annular surface } has { TAIL ~ a radially inner portion } and a radially outer portion , and said continuous seal is located at least on said radially outer portion , while the radially inner portion allows the seal of the valve to be brought into sealing engagement with the tubular body
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH