| 摘要 |
<p>The inventive locking-releasing head is designed for rechargeable powder fire extinguishers, from which the powder is released at positive pressure, and can be used as a primary means for extinguishing class A, B and C fires. The locking-releasing head comprises a body (1) provided with an axially displaceable hollow rod (8). A pressure indicator (11) is attached to one end of the rod and a flange (9) is formed on the other end thereof. A hollow elastic cylinder (19) which embraces the flange and the outer surface of the end section of the rod, thereby forming a valve (21), is arranged inside the hollow rod. The invention is characterised in that the end section of the rod (8) embraced by the wall of the elastic cylinder from outside has a diameter which is larger than the diameter of the middle section thereof and, in essence, is equal to the diameter of the smallest flow area of a seat, and the flange diameter is equal to 1.1-1.2 of the diameter of the smallest flow area of said seat. The inventive head exhibits the high technical-and-economic characteristics, ensures the high reliability of tightness of the valve and seat joint by preventing the valve rubber from flowing into clearances, that is substantial for the rechargeable fire extinguishers the tightness of which must be preserved for a long time.</p> |
