Abstract: A one-way valve for use in the inhalation and/or exhalation flowpath of respiratory protection equipment comprises a housing 1 defining a conduit and a circumferential array of three flexible flaps 2 each extending inwards from the conduit wall and in the direction away from the inlet end I of the valve. Under a pressure differential in the opening direction of the valve each flap is adapted to flex outwards towards the conduit wall and under a reverse pressure differential the free edge 5,5 of each flap is adapted to press in sealing contact with respective portions of the free edges of the neighboring flaps.

Abstract: A respirator has one or more electrodes of e.g. conductive elastomer disposed on the surface of a face sealing member opposite to the surface which seals against the user's face. In use the integrity of the seal formed between the sealing member and the user's face is monitored by monitoring the electrical capacitance across that member between the electrode(s) and the user's face.

Abstract: A respirator has one or more electrodes of e.g. conductive elastomer disposed on the surface of a face sealing member opposite to the surface which seals against the user's face. In use the integrity of the seal formed between the sealing member and the user's face is monitored by monitoring the electrical capacitance across that member between the electrode(s) and the user's face.

Abstract: A one-way valve for use in the inhalation and/or exhalation flowpath of respiratory protection equipment comprises a housing 1 defining a conduit and a circumferential array of three flexible flaps 2 each extending inwards from the conduit wall and in the direction away from the inlet end I of the valve. Under a pressure differential in the opening direction of the valve each flap is adapted to flex outwards towards the conduit wall and under a reverse pressure differential the free edge 5,5 of each flap is adapted to press in sealing contact with respective portions of the free edges of the neighbouring flaps.

Abstract: A respirator assembly e.g. for NBC protection is formed from two separate sub-assemblies. The first sub-assembly comprises a flexible hood (or other suitable headgear), a rigid mounting ring and a peripheral face seal. The second sub-assembly comprise a face plate with lens, oronasal mask and inlet and outlet valves, and is demountably attachable to the ring. The first sub-assembly can be worn on its own with the user breathing ambient air through the front end, the second sub-assembly being added if and when a hazard is encountered. The positioning of the face seal in the first sub-assembly means that a comfortable and reliable fit can be ensured when the sub-assembly is donned prior to a mission, but the user is relieved of the physiological burden of wearing the complete respirator unless and until protection is required.

Abstract: A respirator assembly e.g. for NBC protection is formed from two separate sub-assemblies. The first sub-assembly comprises a flexible hood (or other suitable headgear), a rigid mounting ring and a peripheral face seal. The second sub-assembly comprise a face plate with lens, oronasal mask and inlet and outlet valves, and is demountably attachable to the ring. The first sub-assembly can be worn on its own with the user breathing ambient air through the front end, the second sub-assembly being added if and when a hazard is encountered. The positioning of the face seal in the first sub-assembly means that a comfortable and reliable fit can be ensured when the sub-assembly is donned prior to a mission, but the user is relieved of the physiological burden of wearing the complete respirator unless and until protection is required.