| 摘要 |
A diaphragm (18) for a lung demand valve (10), comprises a CBRN (Chemical, Biological, Radiologican and/or Nucear) layer (58) which is sufficiently resistant to the permeation of at least some CBRN agents and a resilient layer (60) which is resiliently deformable. The CRBN layer (58) is arranged to restrict the permeation of at least some CBRN agents through the diaphragm (18), and the resilient layer (60) is arranged to allow the diaphragm (18) to be resiliently deformed. |
