| 摘要 |
<p>A combined airing valve and fire protection valve comprising an adjustable valve head and a fusible element which is easily influenced by heat so as automatically to induce closing of the valve when fire or overheating occurs. In order to avoid maladjustment of the valve head and possible consequent destruction of the fusible element, the fusible element which takes the form of a fusible nut, is disposed on a valve stem of the valve head so as to follow the valve head if the latter is inadvertently rotated by unauthorized persons.</p> |
