the device is set to maintain a small pressure in excess of the surrounding air pressure inside the face piece. Although the pressure drops when the wearer breathes in, the device always maintains a higher pressure inside the mask than outside of the mask. Thus, even if the mask leaks slightly, there is a flow of clean air out of the device, automatically preventing inward leakage under most circumstances. Although the performance of both types of SCBA may be similar under optimum conditions, this "fail safe" behaviour makes a "Positive pressure" SCBA preferable for most applications.
Full Face Mask
1)With a clear eyesight, can see outside well
2)It has a good gas tightness,
3)With a flexible tape,can be adjustable,
4)it is usually equipped with the breathing apparatus as below
5)It is made of by Kevlar,have a performance of Fire-resistant,can be used in some fire place,especially for fireman
3.Description :
It comprises microphone ,horn, loudspeaker, talk-listen button, concerning wire and receiver.
Flam retardant and high temperature resistant alloy material is used ,which ensure good impact resistance and that it can be used safely under various server environment.
Unique spherical design,the vision rates reached above 91%.work well under any severe environment.
Made from silicon rubber,soft and comfortable.
The outside surface of lens is processed with the most advanced hardening technique in the world,the service life is 3~4 times of that of common protective mask
