| 摘要 |
1297903 Valves A H ANDERSSON & CO AB 9 Jan 1970 [6 March 1969 20 March 1969] 1161/70 Heading F2V A tapered plug lift valve has two plug parts 17, 18 formed with upper ring-shaped portions 19, 21, the upper one 19 of which is in threaded engagement with a rotary actuating shaft 16 and the other 21 of which is engaged in a complementary recess 22 of the upper part and passes with clearance over the shaft 16 when lifted by the upper part. |
