The device 8, wherein an inlet portion of said second flow channel extends between said inlet and said {HEAD ~ first end} of said second flow channel, an outlet portion of the second flow channel extends between said outlet and said second end of said second flow channel, and said closing valve unit is positioned in both said inlet and outlet portions of {TAIL ~ said second flow channel} 
The device 8 , wherein an inlet portion of said second flow channel extends between said inlet and said { HEAD ~ first end } of said second flow channel , an outlet portion of the second flow channel extends between said outlet and said second end of said second flow channel , and said closing valve unit is positioned in both said inlet and outlet portions of { TAIL ~ said second flow channel }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD 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 OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL