Specifications

9
OPERATION OF DURA-CYL MCR 160 / 180 / 200 / 230 / 265MP
27
Filling Procedures
The liquid cylinder is regulated by the US DOT/Trans-
p
ort Canada for transporting liquid oxygen, nitrogen or
argon. The filling of these liquid cylinders must be done
by product weight. This will allow enough gas space
above the liquid to keep the liquid cylinder from becom-
ing liquid full if its pressure rises to the relief valve
setting. The filling weight table (pgs 29 & 30) indicates
the correct product weight for the various relief valve
settings. The standard relief valve setting is 230
psig.(15.9 bar). The filling procedure will show the
proper way to use the filling weight table.
The liquid cylinder is equipped with a liquid and vent
valve that are used during the filling procedure. The liq-
uid 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 vent 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 pressure down in the cylinder.
Filling can be accomplished by either pressure transfer
or pump fill. The following procedure should be used,
refer to the illustration on page 25:
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 liquid valve
(Item 56). Record the new weight. The difference
between this weight and the initial weight is the
weight of the transfer hose.
4
. To determine the total filling weight add the tare
weight of the cylinder, the hose weight and the
p
roper filling weight from the table (pg 29). 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 MP for Oxygen at
230 psi has a product weight of 379 pounds.
5. Open the cylinders vent (Item 58) and liquid
valves (Item 56). Open the transfer line shut-off
valve to begin the flow of product.
6. When the scale reads the calculated total filling
weight turn off the liquid valve (Item 56) on the
cylinder. Close the vent valve (Item 58).
7. 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.
Operating Pressure
The liquid cylinder will automatically maintain a normal
operating pressure between the pressure building por-
tion of the regulator (125 psi- 8.6 bar) and the
economizer portion of the regulator (140 psi- 9.7 bar).
The operating pressure can be set up or down by sim-
ply adjusting the regulator while watching the
pressure gauge. The adjustment range of the regula-
tors is between 50 and 175 psi (3.4 and 12.1 bar).
The gas delivery pressure should not be confused with
the vessel operating pressure. The gas delivery pres-
sure should be adjusted with a separate regulator that
is attached to the gas withdrawal fitting (Item 71).