VENTILVORRICHTUNG FUER TIEFBOHRUNGEN

摘要

Valve device which is fitted in a casing line above the bottom- hole displacement motor and includes a housing 1 provided with an inlet and an outlet for the flowing medium, whereas through- holes 4 for connecting the interior space of the housing to the casing surrounding space are made in the circumferential wall of the housing. In the housing 1, an intermediate wall 5 partitioning the cross section of the housing 1 and having calibrated holes 6 for producing a pressure gradient is fitted at the level above the through-holes 4. A chamber 7 open at the top and connected to the through-holes 4 is accommodated inside the housing 1. Through-passages 10 are produced between this chamber 7 and the housing 1. Accommodated inside the housing 1 is a sealing pair 12 for separating the through- holes 4 in its circumferential wall from the interior space of the housing 1 during the drilling operation. The valve seat 13 of this sealing pair 12 is fastened to the periphery of the chamber 7, whereas the spring-loaded valve element 14, with facilitated adjustment, is arranged under the action of the pressure gradient and has a shaft 15 whose end lies at the level of the top side of the intermediate wall 5.