A tube connection piece is rotatably connected to the coupling sleeve and has {HEAD ~ a portion} provided with {TAIL ~ a sealing ring}, said portion extending sealingly into a socket in the connected position 
provided with
A tube connection piece is rotatably connected to the coupling sleeve and has { HEAD ~ a portion } provided with { TAIL ~ a sealing ring } , said portion extending sealingly into a socket in the connected position
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH