Specifications

11
OPERATION OF DURA-CYL MCR 160 /180 / 200 / 230 / 265 HP
39
Filling Procedures
The high pressure liquid cylinder is regulated by the
DOT/Transportation Canada for transporting liquid oxygen,
nitrogen, argon, carbon dioxide, or nitrous oxide. The filling
of these high pressure liquid cylinders must be done by
product weight. This will allow enough gas space above the
liquid to keep the cylinder from becoming liquid full if its
pressure rises to the relief valve setting. The filling weight
table (pgs 41 &42) indicates the correct product weight for
the various relief valve settings. The standard relief valve
setting is 350 psig (24.1 bar). The filling procedure will show
the proper way to use the filling weight table.
The high pressure liquid cylinder is equipped with a liquid
and vent valve that are used during the filling procedure.
The liquid valve is equipped with a dip tube that extends
into the inner vessel of the cylinder and reaches to the bot-
tom. The vent valve has a dip tube attached to it that also
extends into the inner vessel of the cylinder. This vent tube
is designed to spray the liquid into the top of the vessel so
that pump filling through the vent valve will keep head pres-
sure down in the cylinder.
Filling can be accomplished by either pressure transfer or
pump fill. The following procedure should be used for pres-
sure transfer fillings, refer to the illustration on page 37:
1. Sample the residual gas that is in the cylinder. Purge
the cylinder (refer to the purging procedure, page
58) if necessary to insure the proper purity.
2. Place the cylinder on the filling scale. Record the
weight. Compare this weight to the registered tare
weight on the data plate. The difference is the weight
of the residual gas.
3. Connect the transfer hose to the fill valve (Item 127).
Record the new weight. The difference between this
weight and the initial weight is the weight of the
t
ransfer hose.
4. To determine the total filling weight add the tare
weight of the cylinder, the hose weight and the
proper filling weight from the table (pg 41). The table
indicates the product across the top and the relief
valve pressure down the side. Connect the two
columns to find the proper weight. Example: Dura-
Cyl MCR 160 HP for Carbon Dioxide at 350 psi has
a product weight of 387 pounds.
5. Open the cylinders vent and liquid valves (Item 127
and 128). Open the transfer line shut-off valve to be-
gin the flow of product.
6. If filling CO
2
, adjust the cylinders vent valve to main-
tain pressure in the cylinder and fill hose. The
equipment must maintain pressures above 70 psi
(4.8 BAR) during the transfer. Liquid CO
2
will turn
into dry ice at lower pressures.
7. When the scale reads the calculated total filling
weight, turn off the liquid valve (Item 127) on the
cylinder. Close the vent valve. It is important to
maintain pressure above 70 psi (4.8 bar) if filling
CO
2
or N
2
0. Do not allow the cylinder to vent down
after filling.
8. Close the transfer line shut-off valve and relieve the
pressure in the transfer line. Remove the transfer
line. Remove the cylinder from the scale.