Abstract: The present invention relates to a ventilation system for a protective suit for use in hazardous environments. In a further aspect it concerns the protective suit itself. An air purifying respirator draws air from outside the protective suit through a filter, supplies filtered breathing air via a breathing hose to a space within the face piece, and supplies filtered ventilating air via a ventilating hose to the interior of the protective suit. A ventilation valve in the ventilating hose automatically closes only during periods of high breathing demand to counter a pressure drop inside the face piece.

Abstract: The present invention relates to a particular type of fan-forced positive pressure breathing apparatus, commonly known as Powered Air-Purifying Respirators (PAPRs). In particular the invention concerns monitoring the operation of such equipment. In a first aspect, the invention provides a powered air-purifying respirator which includes data collection means to enable the volume of air drawn through the filter to be determined. In another aspect, the invention comprises a management system for monitoring and analyzing operational data from at least one powered air-purifying respirator. The management system includes data collection means associated with each respirator to enable the volume of air drawn through that respirator's filter to be determined, and electronic data processing apparatus into which the data collected by the data collection means is uploaded for analysis.

Abstract: A forced air breathing apparatus which includes a face piece (20a) for covering at least the nose or mouth of a wearer, a pump unit (10) arranged to supply air to a space within the face piece (20a), a filter (13) to filter air entering the face piece (20a) and valve means to control the flow of air from the pump unit (20) to the face piece (20a) during inhalation and from the face piece (20a) during exhalation. The pump unit (20) includes a fan (12) driven by an electric motor (11). The valve means includes an air inlet valve (19) and an air outlet valve (22), the air outlet valve (22) being maintained in a closed position during inhalation through the air inlet valve (19) by air pressure from the pump unit (20) and being opened by exhaled air. The exhaled air also acts to close the air inlet valve (19) and prevents the entry of exhaled air to the pump unit (20). The fan (12) is a centrifugal fan driven at a substantially constant speed.