| 摘要 |
<p>A blow molded drum has a port 35 including a neck 38 with exterior threads and a sleeve 24, having an inner cylindrical sealing surface and a shoulder, fusion bonded in the neck. A drop-in down tube assembly 26 seats with the shoulder and has an upwardly extending nipple 104. A dispense head 32 or closure 34 radially seals within the sleeve 24, the closure 34 or a retainer 156 being screwed to the neck 38. The dispense head 32 has a first flow duct 142 extending to a nipple engaging portion 148 and a second flow duct 144 leading to an annular space 152 around the nipple 104 for a return fluid line. The closure 34 may have an 0-ring for sealing with the cylindrical sealing surface of the sleeve 24, and a pathway 270 including a spiral gap 266 between the cooperating buttress threads 226, 80. A microporous membrane 250 may also be placed in the pathway 270 to allow venting.</p> |
