| 摘要 |
<p>1481331 Inflatable pig OIL STATES RUBBER CO 30 Sept 1974 [1 Oct 1973] 42328/74 Headings F2N and F2V A pipeline pig comprises a ball 1<SP>11</SP> inflatable so as to vary its size precisely a valve assembly bonded into the wall and positioned at the base of a recess 211 for protection, the valve assembly including a ball 22 trapped within a shaped and threaded insert 16 by means of a seal 20 and providing temporary sealing, e.g. after inflation, and a removable plug 26 for affecting a more permanent seal. The valve sleeve 32 and recess 211 are as long as possible, determined by the thickness of the wall 1<SP>11</SP>, which is locally increased internally in the valve area if necessary. Plug 26 has a seal 28 and may have a core (55, Fig. 8, not shown) bonded to it with a screwdriver slot at its other end in order to fill the recess 211 for further protection. Special adaptors (40, Fig. 7, not shown) are used with deep recesses where an inflation attachment cannot be directly attached to the threaded end 24.</p> |
