Equipment Description - CAIRE HELiOS Plus Technical & Service Manual

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Equipment Description

Figure 3: HELiOS portables components
The HELiOS 300 and HELiOS 850 are lightweight portable
liquid oxygen units designed to deliver supplementary oxygen
therapy to patients as prescribed by a physician. The units are
filled from a liquid reservoir for ambulatory use, or used as a
stationary conserving device when attached to a HELiOS reser-
voir using a flexible oxygen supply line. Enclosed in a durable
plastic case, HELiOS portable units incorporate a stainless steel
cryogenic container with the valves, plumbing, and associated
hardware necessary to convert liquid oxygen to gaseous oxygen
and deliver it to the patient at or near room temperature.
1. Cryogenic Container This assembly is a double walled
vacuum insulated Dewar for storing liquid oxygen (LOX) at
approximately -173°C/-280°F. The inner vessel is designed
to safely hold liquid oxygen and is protected from over pres-
surization by the primary relief valve. Vacuum insulation
between the inner and outer vessel keeps outside heat from
causing the cold liquid inside to evaporate.
2. Plumbing System The plumbing system consists of the
breathing (warming) and vaporizing coils, vent valve, R/E
valve, SRV, and QDV. The plumbing is responsible for
both filling the portable and drawing the liquid oxygen out
of the cryogenic container so that it can be delivered to the
patient.
3. Case The durable plastic case protects and encloses the cryo-
genic container, plumbing system, and flow control valve.
The plastic case also contains vents to improve circulation of
air and minimize icing.
4. Liquid Content/Level Indicator A mechanical spring-bal-
anced indicator used to display the liquid oxygen contents
of the HELiOS portable. It is built into the rear cover of the
unit, and contains a viewing window. When the patient lifts
the unit by its strap, the window displays a green bar whose
height is proportional to the amount of liquid in the unit.
5. Demand Flow Control Valve (FCV) The flow control valve
allows the patient to select either demand or continuous oxy-
gen flow. It is a pneumatic demand valve that utilizes a dual
lumen cannula to detect the negative pressure produced by a
patient's inhalation and initiate flow.
HELiOS Portables Technical Service Manual • PN 20562190 Rev E
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