| 摘要 |
<p>A control system for an underground flow valve, e.g. gas or liquid, has an adaptor (6) between the valve shaft (9) and a drive shaft (4) whose top end, near or at ground level, is profiled to be gripped by a release tool. The adaptor has a two component construction with an outer metal profile and an inner plastic element which is secured into the metal shell by ratchet grips. The plastic element has profiled grips to connect to the drive shaft, with the plastic having a constant thickness over the drive profiles.</p> |
