Specifications

6
FEATURES
12
G
eneral
The Chart cryogenic liquid cylinders were designed to
furnish a convenient, reliable, and economical method
f
or the transportation and delivery of liquefied gases.
Important features of these liquid cylinders include:
* The Dura-Cyl/Cryo-Cyl Series liquid cylinders are
constructed with an all stainless steel internal
support system designed for low heat leak and
high strength.
* These cylinders are easily handled by one person.
* Gas stored in liquid form in a Dura-Cyl/Cryo-Cyl
Series liquid cylinder is more pure than gas
stored in conventional cylinders.
* During periods of non-use, pressure will rise in a
cryogenic liquid cylinder. The highly efficient in-
sulation system minimizes the rate of pressure
rise. This allows for a reasonable period of non-
use without any venting of product from the
pressure relief valve.
* Internal pressure building and vaporization sys-
tems permit a continuous flow of gas without
need for an external vaporizer.
* The pressure control regulator automatically
maintains working pressure with minimum prod-
uct loss.
* Cylinders can be used singularly or can be man-
ifolded to provide a continuous gas supply.
Performance
The performance of a liquid cylinder can be shown in its
ability to hold a cryogenic liquid and dispense it as a gas.
The normal evaporation rate (NER) is an indication of
how well the insulation system performs its ability to
hold cryogenic liquid. The Dura-Cyl/Cryo-Cyl Series
NER is shown on the specification chart on pages
14 thru 16. Figure L indicates how the insulation per-
formance effects the holding time for CO
2
or N
2
O.
The pressure building system can be measured by
how fast it can increase pressure in the liquid cylin
-
der (Figure H) and how well it maintains pressure
while gas is being withdrawn from the cylinder
(Figures I and K).
Figure H illustrates the expected liquid cylinder pres-
sure building rate (with liquid nitrogen) versus time.
0
10
1
0 20 30 40 50 60 70 80 90 100
20
30
40
50
60
70
80
90
100
110
120
TIME (MINUTES)
PRESSURE (PSIG)
1
00%
FULL
7
5%
FULL
5
0%
FULL
2
5%
FULL
2
5%
FULL
Dura-Cyl Series
Cryo-Cyl 80HP
10 20 30 40 50 60 70 80
24
50
75
100
125
150
TIME (MINUTES)
PRESSURE (PSIG)
90% FULL 70% FULL*
15% FULL*
75% FULL*
500 SCFH
90% FULL 80% FULL*
100 SCFH
17000 SCFH
2000 SCFH
150 SCFH
5000 SCFH
EMPTY
Dura-Cyl Series
Cryo-Cyl 80HP
Figure H
Figure I
Figure I illustrates how the pressure builder will maintain
delivery pressure at various flow rates. (See note 1 and 2)
Notes:
1. Curves assume liquid withdrawal from tank and
use of free standing vaporizer.
2.
Pressure builder valve open and pressure control
regulator at 125 psi.
* Amount of liquid left at conclusion of test
T
he performance of the vaporizer to convert cold liq-
uid into gas is shown by how the outlet gas
temperature drops as the gas flow rate increases.