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5.3.
PNEUMATIC CIRCUIT
It basically consists of the pressure reducer valve connected to the cylinder,
equipped with a system of reduction of downstream pressure which reaches the
demand valve through a medium pressure hose. The demand valve is made in
metal for parts exposed to medium pressure and in plastic for the parts exposed
to low positive pressure (breathable pressure), while a membrane in silicone
assures the reduction from the medium pressure to the breathable pressure.
6.
CHECKS PRIOR TO USE
Prior to use it is necessary to verify:
1)
the state of charge of the cylinder through the reading of the gauge
connected directly to the cylinder valve. The needle of the gauge within
the green sectors (corresponding one to 200bar working pressure and one
to 300bar working one) of the dial indicates that the bottle contains
sufficient air for a duration of use equal to the nominal duration (at a
breathing rate of 20 cycles/min x 1.75litres x cycle);
2)
integrity of the seal in order to assess that the device has not been opened.
Such a seal is made by a white lace placed across a hole on the hand wheel,
blocked by a plastic fastener locked around the neck of the valve. In case
the hand wheel of the valve has been opened, the white lace drops out of
the fastener and will turn freely with hand wheel.
7.
PREPARATION FOR USE
The following information provides the basic steps to perform just before use
of SEKUR NAVY MASK.
7.1.
Donning the apparatus through the shoulder strap and adjust the belt
with the Velcro.
7.2.
Open the cylinder valve by turning the hand-wheel counter-clockwise
7.3.
Put on the mask so that the sealing lip adapts in a leak tight way to the
face (see instructions for use of the mask C607 SP/A or SFERA SP/A)
7.4.
Activate the demand valve by inhaling deeply and leave immediately
the place with unbreathable air.
