Dräger PSS BG 4 plus User Manual

6 Dräger PSS BG 4 plus
Description
2 Description
2.1 Product overview
2.1.1 Closed-circuit breathing apparatus
► Illustrations on
page 5
1 Exhalation breathing hose
2 Connecting piece with sealing cap
3 Bayonet ring
4 Sentinel
5Waist belt
6 Cylinder valve
7 Bypass valve
8 Inhalation breathing hose
9 Reinforcing rings
10 Safety catch on the pressure relief valve
11 Breathing air cooler
12 Hand wheel with anti-vibration strap
13 Carrying frame
14 Belt
15 Pressure relief valve
16 Drain valve
17 Compressed oxygen cylinder
18 Breathing bag
19 Spring holder
20 Control line
21 CO
2
absorber
► Illustration page 5 (figure B
)
1 Pressure reducer
2 Yellow medium pressure hose to minimum valve
3 Safety catch
4 Blue medium pressure hose of constant metering valve
5 Sensor unit/switch box
6 Line to sensor unit
7 Minimum valve
2.1.2 Sentinel
► Illustration page 5 (Fig
ure A)
1Display
2 Panic button
3 Right button
4 Function key for motion sensor
5 Red LEDs
6 Alarm device
7 Green LED
8 Left button
2.2 Functional description
2.2.1 Closed-circuit breathing apparatus
The PSS BG 4 plus closed-circuit breathing apparatus is a
regeneration unit with pure oxygen supply in excess pressure
version. A positive pressure in the breathing circuit prevents
ambient air from entering the system.
The breathing air is circulated in a closed breathing circuit.
The carbon dioxide contained in the exhaled air is absorbed in
a CO
2
absorber. Either a disposable cartridge or a refillable
cartridge can be used.
The breathing air is enriched with oxygen from the compressed
oxygen cylinder:
 via constant metering valve in the case of low breathing
rates
 in the case of higher breathing rates additionally via the
minimum valve or the bypass valve which is then manually
operated.
Before the regenerated air is inhaled again, it flows through the
air cooler. To reduce the temperature of the inhaled air further,
and thus minimize the physical discomfort of the wearer, the air
cooler can be filled with ice. The use of ice in the cooling
system is only required at ambient temperatures above 32 °F
(0 °C). At temperatures below 32 °F (0 °C), ice must never be
used.
The closed-circuit breathing apparatus is connected to a full
facepiece by means of the connecting piece. One version of
the connecting piece has a condensate trap where the
condensate from the breathing air collects during use.
A water absorber is available as an option. It is connected to
the drain valve on the breathing bag and absorbs the water
that is delivered via the valve.
To be able to use the closed-circuit breathing apparatus in
particularly low or high temperatures, the following
accessories are available:
 Radiant heat protection for the breathing hose and the
protective cover:
Protects against radiant heat and prevents foreign bodies
penetrating through the openings into the carrying frame of
the closed-circuit breathing apparatus.
2.2.2 Electronic monitoring system
The electronic monitoring system comprises a sensor unit,
switch box and Sentinel. The electronic monitoring system is
connected to the breathing circuit via the control line.
The sensor unit measures the available oxygen pressure in the
compressed oxygen cylinder and the pressure in the breathing
circuit. The values are compared in the switch box. Alarms are
triggered at specific values.
Page 6
Draeger Training 11/16 rev 1

Dräger PSS BG 4 plus Specifications

General

Brand	Dräger
Model	PSS BG 4 plus
Category	Diving Instrument
Language	English