| 摘要 |
1465429 Valves TROX GmbH Gebr 2 April 1975 [2 April 1974] 13408/75 Heading F2V [Also in Division A5] A fire closure in a ventilating or air conditioning duct comprises a casing 1 divided into two parts 2a and 2b between which there is an asbestos ring 3 and a pivotally mounted anti-fire gate 5 made of asbestos cement which, when closed, abuts against strips 6 and asbestos foam insert 7 as seal. |
