Valve assembly for packing fluid under pressure and packing provided with such assembly

摘要

The valve assembly for non-returnable packing comprises a valve housing including a main valve and an auxiliary valve the latter being initially kept in opened position through a resilient locking device which is unlocked, at the end of a first filling through a displacement of the main valve beyond its position of normal opening under the action of a long travel filling tap. The auxiliary valve is then forced to rest on its seat by means of a spring with low calibration. Any depression caused by tapping would provoke the opening of the auxiliary valve, while any overpressure resulting from filling would hit the auxiliary valve in a closed position.