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Extended Duration Breathing Apparatus (EDBA) Instructor Reference Guide - February 2018, Version 1.0
@
NARU_Education
www.narueducationcentre.org.uk
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LDV manufactured from glass-filled
nylon which provides a high degree
of strength and durability.
Rubber shroud covers the mechanism.
Mechanism consists of a balanced
piston assembly, banjo spindle spring
lever and a silicon diaphragm
(red button) or rubber (CBRN - green).
Operates on first breath principle.
Operating pressures:
First breath = -1 to -25 m/bar
Reduced into mask = 1 to 3.9 m/bar
Activate exhalation valve = 4.2 to
5.7 m/bar
Has a type A push-in connector to
the face piece (‘P’ connection).
Able to deliver 500 LPM.
Lung Demand Valve
10
Red/ Green button = reset (close circuit).
Black button = (depress for
supplementary air supply).
Once connected to the front port of the
facemask the LDV can rotate,
accommodating changing orientations
of the wearer. In addition, the medium
pressure connection to the LDV by
means of a swivelling banjo allows
another degree of freedom. The end
result is that the LDV and hose will
remain streamlined with the body.
The balanced piston assembly and banjo
spindle spring lever work in conjunction
to allow the flow of air dependant on the
wearer inhaling or exhaling.
Black button = depress activates free flow
Green/red button = reset (close circuit)
