Concoa 620 Series User manual

620 Series
Switchover
System
(Shown with Optional Line
Regulator)
INSTALLATION AND OPERATION INSTRUCTIONS
Before Installing or Operating, Read and Comply with These Instructions
Controls Corporation of America
1501 Harpers Road Virginia Beach, VA 23454
To Order Call 1-800-225-0473 or 757-422-8330 • Fax [phone]
www.concoa.com April 2003
Supersedes May 2000
Certied ISO 9001
ADI 3174-E

2
3
DESCRIPTION OF PRODUCT
The 620 series switchover is an automatic switchover system designed to provide a continuous supply of LASER gas.
This unit may be used with one cylinder per side, or used with a manifold that has increased storage capacity. The
inlet of the switchover system may be purchased with open ports, diaphragm valves, manifold connectors, or exible
pigtails. The system, when congured with manifold connectors, is for use with the 628 Series Maniex system. If
constant outlet pressure is required, a regulator will need to installed as part of the switchover system (as with the
620 3XX8 or 620 4XX8 models) The standard switchover system will maintain a variable line pressure within the
values shown in the table below:
Preset
Regulator
Preset
Regulator
Standard System System with Line Regulator
(620 XXX8)
Relief Valve Relief Valve
Line Regulator
Priority Valve
Regulator
Priority Valve
Regulator
Figure 1. 620 System Congurations.
Figure 2. Optional remote alarm for
the 620 Series Switchover.
MODEL NUMBER OUTLET PRESSURE (without Line Regulator)
620 2XXX 35-95 PSI (2.4-6.5 BAR)
620 3XXX 65-135 PSI (4.5-9.3 BAR)
620 4XXX 160-235 PSI (11-16.2 BAR)
620 5XXX 260-360 PSI (18.25 BAR)
620 7XXX 120-185 PSI (9.0-12.8 BAR)
With the optional line regulator, the user will be able to maintain a constant line pressure by adjusting the line
regulator knob.
MODEL NUMBER OUTLET PRESSURE
620 3XX8 0-100 PSI (0-7 BAR)
620 4XX8 0-250 PSI (0-17 BAR)
When congured with the remote alarm, the remote alarm provides audible and visual warning that a changeover
is about to occur. Pressing a button on the front of the remote alarm silences the audible alarm. The LED’s on the
remote alarm indicate the status of the left and right banks.

2
3
INTENDED USE OF PRODUCT
This product is intended for use with Laser purity gases such as helium, nitrogen, carbon dioxide, or mixtures of
these three gases.
USER RESPONSIBILITY
This equipment will perform in conformity with the description contained in this manual and accompanying labels
and/or inserts when installed, operated, maintained, and repaired in accordance with the instructions provided. This
equipment must be checked periodically. Improperly working equipment should not be used. Parts that are broken,
missing, worn, distorted or contaminated, should be replaced immediately. CONCOA recommends that a telephone
or written request for service advice be made to CONCOA Customer Service in Virginia Beach, Virginia, PHONE:
1-800-225-0473, FAX: [phone], or E-MAIL: [email protected].
This equipment or any of its parts should not be altered without prior written approval by CONCOA. The user
of this equipment shall have the sole responsibility for any malfunction that results from improper use, faulty
maintenance, damage, improper repair, or alteration by anyone other than CONCOA or a service facility designated
by CONCOA.
CUSTOMER ASSISTANCE
In the event of equipment failure, call CONCOA Customer Service. Please be prepared to provide the model number
and serial number of the equipment involved, in addition to some details regarding its application. This would
include inlet and outlet pressures, ow rate, environmental conditions, and gas service.
Things to consider before removing the system from the box….
1. Know the properties and special handling requirements of the gas being used. Many gases are quite dangerous
(ammable, toxic, corrosive, simple asphyxiant, or oxidizers). Equipment failure or misuse may lead to
problems such as a release of gas through the relief valve or regulator diaphragm. Proper safety measures
should be established to handle these and other component failures.
2. Be sure that the assembly purchased is suitable for the gas and type of service intended. The system label
provides the following information:
a. Model number
b. Serial number
c. Maximum inlet pressure
Be sure that the equipment received conforms to the order specications. The user is responsible for selecting
equipment compatible with the gas in use, and conditions of pressure, temperature, ow, etc. Selection
information can be found in CONCOA technical data sheets. In addition, CONCOA representatives are
trained to aid in the selection process.
3. Inspect the assembly upon receipt to be sure that there is no damage or contamination. Pay particular attention
to connecting threads. While CONCOA assembles system components to exacting leak-tight standards, the
customer should also inspect for any loosening of parts that may occur in shipping or installation. Loose parts
may be dangerously propelled from an assembly. If there are adverse signs (leakage or other malfunction),
return the assembly to the supplier. While it is advised that soiled regulators be returned for cleaning, simple
external dust or grease may be removed by a clean cloth and if required with aqueous detergent suitable for
the application. If there are signs of internal contamination, return to the supplier.
4. Before system startup, it is recommended that all systems be pressure tested, leak tested, and purged with an
inert gas such as nitrogen. To accomplish this with connections other than a CGA 580, it will be necessary
to use an adapter. The recommended use of an adapter is for temporary use, for start-up and system checks
only. Adapters should never be used on a permanent basis.

4
5
GENERAL SAFETY PRACTICES
Comply with precautions listed in C.G.A. Pamphlet P-1, Safe Handling of Compressed Gases in Containers.
Consult the cylinder distributor for the proper use of cylinders and for any restrictions on their use (such as ow
rate and temperature requirements).
Store cylinders with valve caps screwed on, and cylinders chained to a supporting wall or column.
Handle cylinders carefully and only with valve caps screwed on. The cap will reduce the chance that the cylinder
valve will break off if the cylinder is accidentally dropped or falls over. The cap also protects the cylinder valve from
damage to screw threads, which could cause leaky connections.
All manifolds used with ammable gases should be provided with approved ashback arrestors to stop any burning
gas in the pipeline from getting back to the manifold or cylinders.
No smoking should be permitted near oxygen, nitrous oxide, any other oxidizer, ammable gases, or ammable
mixtures, or in areas where cylinders are stored.
Where oxygen or nitrous oxide is used, the manifold and cylinders must be kept clean. No oil, grease, or combustible
substances should come in contact with oxygen or nitrous oxide storage or handling equipment. Such materials in
contact with oxygen or nitrous oxide are readily ignitable and when ignited, will burn intensely.
Never strike an electric arc on a gas cylinder of any kind.
Never lift gas cylinders with a magnetic lifting device.
Never use an open ame when leak testing.
Always open valves slowly when high-pressure gases are being used.
Always be sure that a cylinder contains the correct gas before connecting it to any manifold.
Always leak-test any manifold or distribution pipeline before using.
Always be sure that the gas in a pipeline is the correct gas for the intended use.
Always close all cylinder valves before disconnecting cylinders from a manifold.
Always remove all empty cylinders from a manifold before connecting full cylinders.
Always test cylinders to be sure the cylinders are full before connecting to a manifold.
All gas distribution piping systems must meet the appropriate industrial standards for the intended service and must
be thoroughly cleaned before using. For the United States, some applicable safety rules and precautions are listed
below:
1. American National Standards Institute standard Z49.1, Safety in Welding and Cutting, American Welding
Society, 2501 NW Seventh Street, Miami, Florida 33125
2. N.F.P.A. Standard 51, Oxygen-Fuel Gas systems for Welding and Cutting, N.F.P.A., 470 Atlantic Avenue,
Boston, Massachusetts 02210
3. N.F.P.A. Standard 51B, Cutting and Welding Processes (same address as #2).
4. CONCOA publication ADE 872, Safety Precautions in Welding and Cutting.

4
5
5. Local Ordinances
6. O.S.H.A. Standard 29 CFR
7. C.G.A. Pamphlet C-4, American National Standard Method of Marking Portable Compressed Gas Containers
to Identify the Material Contained.
8. C.G.A. Pamphlet G-4, Oxygen – Information on the properties, manufacture, transportation, storage,
handling, and use of oxygen.
9. C.G.A. Pamphlet G-4.1, Equipment Cleaned for oxygen service.
10. C.G.A. Pamphlet G-4.4, Industrial Practices for Gaseous Oxygen Transmission and Distribution Piping
Systems.
11. C.G.A. Pamphlet G-5, Hydrogen – Information on the properties, manufacture, transportation, storage,
handling, and use of hydrogen.
12. C.G.A. Pamphlet G-6, Carbon Dioxide – Information on the properties, manufacture, transportation,
storage, handling, and use of carbon dioxide.
13. C.G.A. Pamphlet G-6.1, Standard for Low Pressure Carbon Dioxide Systems at Consumer Sites.
14. C.G.A. Pamphlet P-1, Safe Handling of Compressed Gases in Containers.
15. C.G.A. Safety Bulletin SB-2, Oxygen Decient Atmospheres.
*C.G.A. pamphlets can be obtained from the Compressed Gas Association, 1235 Jefferson Davis Highway, Arlington,
VA 22202-3239, [phone]. Publications: [phone]. Fax: [phone].
LOCATION
Keep all cylinders and manifolds away from any source of high temperature over 120°F (50°C) or possible re hazards.
High-pressure gas contained in a closed cylinder becomes increasingly dangerous when exposed to high temperature
because pressure increases and the strength of the cylinder decreases. Manifolds installed in open locations should
be protected from weather conditions. During winter, protect the manifold from ice and snow. In summer, shade
the manifold and cylinders from continuous exposure to direct sunlight. Always leave access to the manifold for
cylinder replacement.
The site chosen for the manifold installation shall be level, well ventilated, and at a safe distance from sources of
ames, sparks, and excessive heat. The manifold should not be placed in an area that may subject the manifold to
damage from passing trucks, cranes, or other heavy machines. Oxygen manifolds must not be installed under shafting,
belting, or other places where oil can drip on them. For other location guidelines, see NFPA standard 51.
INSTALLATION
Installing the system:
1. Be sure to consider all factors when selecting materials.
2. Do not use oil or grease on ttings.
3. Be sure that all ttings are secure and leak tight. Teon tape should be used on pipe threads.
4. Relief valve: The purpose of the relief valve is to protect the autoswitch system and its components only. If
there is pressure sensitive equipment downstream of the autoswitch system, it is recommended that a relief
valve be installed in the line to protect this equipment.
5. Purge devices: These devices are optional. Purge devices are used to remove unwanted gases from the system
before and after use. Purging is typically done with an inert gas such as nitrogen (grade 5.0 - 99.9991%
pure). See the appendix for a sketch of the purge kit.

6
7
Mount the switchover system to a at surface using the appropriate hardware at hole locations provided in the bracket.
Dimensions for these holes are shown below:
Relief Valve
Figure 3. Relief valve location on the
620 Series Switchover.
Figure 4. Mounting bracket
for the 620 Switchover.
If installing to a 628 Series Maniex manifold, install the inlet connection and then follow the instructions provided
with the manifold. If installing for use with cylinders, provide enough clearance between the top of the cylinder
and the switchover system. The typical installation for high-pressure cylinders needs 66 inches between the oor
and the “INLET” port.
4.37 in (111 mm)
.88 in (22 mm)
4 in (102 mm)
.44 in (11 mm)

6
7
When installing the inlet and outlet connections to the regulator, use an open-end wrench, not a pipe wrench.
The  NPT connections require the use of Teon tape on the threads to make a gas tight seal. On stainless steel
connections, the Teon tape helps prevent the connections from galling together when tightening or loosening.
Follow these rules when using Teon tape.
Leave Enough Space For
Cylinders As Necessary
Figure 5. Switchover spacing.
Figure 6. Tape Installation procedures.
Before applying Teon tape, inspect the NPT threads and if necessary, clean the tting to remove any dirt or thread
sealant that remains on the threads. Start the Teon tape on the second thread as shown above; make sure the tape
does not overlap the end of the tting. As the tape is wrapped in the direction of the thread spiral, pull tightly on
the end of tape so that the tape conforms to the threads. Apply two overlapping layers of Teon tape. Cut off the
excess tape and press the end rmly into the threads.
Installing the inlet connection:
620 X1XX or 620 X2XX – congured for multiple cylinders per side: See the appendix for the pictorial representations
of the system. Tape all NPT connections as described in the procedure above. If purchased with a purge kit and
multiple cylinders per side, install the purge kit into the inlet port. The  male NPT end of the manifold connector
will need to be installed in the “INLET” port of the regulator, purge kit, or the diaphragm valve port. The other
end of the manifold connector will connect to the starter block of the 628 series Maniex system. Please follow the
instructions provided with the Maniex system when connecting and operating the manifold system.

8
9
Congured for single cylinder use: See the appendix for the pictorial representations of the system. If purchased
with the purge kit, install the purge kit into the “AUX INLET”. If purchased with pigtails, the male  NPT end of
the pigtail is installed into the “AUX. INLET “ port or in the open port of the diaphragm valve or purge kit.
The CGA or foreign inlet connection available at the other end of the pigtail is dependent on the purchased system.
The cylinder connection is specic to the particular cylinder of gas to be used. Some cylinder connections do require
the use of a gasket. Please note that the material of the gasket must also be compatible with the type of gas being
used. Be familiar with the type of connection being used, and its proper procedures for installation. Also note that
the pigtails supplied with the system have check valves installed on the cylinder connection end.
Connecting to a cylinder:
1. Before removing the cylinder cap, move the cylinder of gas to the work site:
a. Secure cylinder to the oor, wall, or bench with appropriate chain, strap, or stand to prevent toppling.
b. Remove the cylinder cap.
c. Be sure the cylinder valve is tightly closed (clockwise)
d. Remove the cylinder valve plug, if any.
e. Inspect the cylinder valve and threads for damage or contamination.
2. Secure the cylinder connection to the cylinder in the following manner:
a. Threading the nut onto the cylinder connection should be easy. Do not force. If it doesn’t t, the
connection may be wrong for the type of gas being used.
b. Left-hand threads are used on some cylinder connections. A notch in the middle of the hex nut typically
indicates a left-hand thread.
c. Gaskets are used on some inlet connections. Be sure the gasket is in good shape. Do not over-tighten
to avoid squashing the gasket into the gas line. Keep extra gaskets on hand.
d. Never use oil or grease on regulator or cylinder ttings, as it may contaminate pure gases, or create a re
hazard.
Installing the outlet connection:
The standard system has the outlet connection at the top of the switchover system. The connection is a ” stainless
steel tube connection. Connect suitable tubing to the connection that is rated to the pressure of the system. See the
appendix for instructions on making up the Swagelok tube connection.
Pressurizing the system for the rst time:
Before system startup, it is recommended that all systems be pressure tested, leak tested, and purged with an inert gas
such as nitrogen. To accomplish this with connections other than a CGA 580, it will be necessary to use an adapter.
The recommended use of an adapter is for temporary use only, for system start up and checks. Adapters should
never be used on a permanent basis.
1. Wear safety glasses and gloves.
2. Be sure that both ends of all hoses or pigtails are secured before pressurizing. On systems with the optional
line regulator, turn the line regulator knob counterclockwise until the knob stops turning.
3. When rst pressurizing, do not stand in front of or contact the switchover system. Slowly open the cylinder
valve. Observe the high pressure gauge for a rise in pressure up to full cylinder pressure. Warning - if this
system is not equipped with the optional line regulator, the gas will ow from the outlet when the cylinder
valve is opened.
4. Keep the hand wheel or wrench on the open cylinder valve at all times, to allow prompt emergency shut-
off.

8
9
5. Inspect all connections for leaks and x any leaks. A leak detection solution may be applied to the connections
(if compatible with the application) which indicates leaks by bubbling. To further check for leaks, or if the
leak detection solution can not be used - after pressurizing the system - close the cylinder valve for a period
of time (recommended 24 hours), and observe the high pressure gauge for a drop in pressure. If so indicated,
recheck the CGA connection and all other high-pressure port connections. If equipped without the line
regulator, the outlet connections will also need to be rechecked.
6. Never attempt to x a leak under pressure. If leaks are detected, depressurize the system and retighten the
connection. Begin again at step 3.
7. If equipped with the optional line regulator, slowly turn the line regulator knob clockwise. This will increase
the pressure on the delivery side of the system. Adjust to the desired working pressure and again check for
leaks using the methods described above.
OPERATION
The arrow on the priority valve always points to the primary side; the bank opposite the primary side is considered the
reserve side. Starting with the arrow pointing to the right side, gas will ow from the right side cylinder. As the gas
in the primary side is depleted, the gas pressure will drop on the gauge of the primary regulator. When the pressure
drops to the pressure setting of the reserve side regulator, ow will begin from the reserve cylinder. This is called a
changeover. At this point, the gas pressure on the reserve side (preset regulator) will drop. This indicates that its
time to change the cylinders on the primary side. Before removing the nearly depleted primary cylinder, the priority
valve should be rotated 180°. This makes the reserve cylinder, the primary source. Remove the depleted cylinder
and replace with a full cylinder. Before removing the cylinder be sure to close the cylinder valve and any other valves
that connect the cylinder to the system. The full, replacement cylinder is now the reserve cylinder.
Note: while changing cylinders on one side, there will be no interruption in ow. A depleted cylinder will have the
following gas pressure remaining:
MODEL NUMBER OUTLET PRESSURE (Without Optional Line Regulator)
620 2XXX 35-95 PSI (2.4-6.5 BAR)
620 3XXX 65-135 PSI (4.5-9.3 BAR)
620 4XXX 160-235 PSI (11-16.2 BAR)
620 5XXX 260-360 PSI (18.25 BAR)
620 7XXX 120-185 PSI (9.0-12.8 BAR)
MODEL NUMBER OUTLET PRESSURE (With Optional Line Regulator
620 3XX8 160-235 PSI (11-16.2 BAR)
620 4XX8 445-545 PSI (30.7-37.6 BAR)
Gas will continue to ow from the primary side until the outlet pressure of the preset regulator matches the pressure
of the priority valve regulator. (The pressure setting of the priority valve regulator changes when the knob is turned
180°). When the gas pressure stops dropping on the preset regulator and starts to drop on the priority valve regulator,
it is time to change the left cylinder. The knob is rotated 180° to the right before the left cylinder is changed. It
is helpful to maintain a log of cylinder pressure, noting which direction the arrow is pointing on the priority valve.
When the pressure gauge is very low and the reserve side indicates that gas has begun to ow from the reserve cylinder,
it is time to rotate the knob and attach a full cylinder in reserve.

10
11
If the knob is not rotated before the empty cylinder is changed, two things can happen. First, gas may ow from
the fully charged cylinder to the in-use cylinder. This is because the pressure setting of the regulator on the primary
side allows the regulator main valve to remain open. Second, when the cylinder is changed, gas will begin to ow
from the new cylinder, stopping ow from the cylinder in use. This means the “in-use” cylinder may be partially
empty. After several cycles, it is possible that the reserve cylinder may empty shortly after a switchover occurs. Always
remember to rotate the knob on the priority valve regulator before changing a depleted cylinder.
MAINTENANCE
At regular intervals, the system should be checked for leaks and proper function (see trouble shooting). Any leaks
in the system should be corrected immediately. At no time should the preset regulator’s or priority valve regulator’s
pressure settings be changed.
TROUBLESHOOTING
Typical symptoms listed below indicate regulator malfunctions needing repair. Replace immediately with a clean,
repaired and tested, or new system.
1. Gas leakage at the line regulator outlet when the adjusting screw of the line regulator is completely backed
out.
2. With no ow through the system (downstream valves closed and adjusting screw in) line pressure steadily
increases above set pressure.
3. Gas leakage from spring case (adjusting screw/knob end off regulator).
4. Gas leakage from any joint.
5. Excessive drop in working pressure with regulator owing gas.
6. Gas leakage from relief valve.
7. Gas leakage from gauge
8. Gauge does not return to zero when not under gas pressure
9. Gauge does not consistently repeat the same reading.
10. The system makes a noise or hums.
If the switchover system seems to be using gas from the primary and reserve cylinders (pressure is decreasing on both
inlet gauges at the same time), do the following:
1. Make sure the priority valve knob is turned fully to the right or left.
2. Observe the inlet pressure. It may be necessary to do this during the heaviest use of the system. If the inlet
pressure is below the values listed below, replace the high-pressure cylinders. If liquid cylinders are used and
the inlet pressure increases signicantly when the system is not in use, then the system is over-withdrawing
the liquid cylinders. Additional capacity may be added to the system to prevent this.
MODEL NUMBER OUTLET PRESSURE (Without Optional Line Regulator)
620 2XXX 35-95 PSI (2.4-6.5 BAR)
620 3XXX 65-135 PSI (4.5-9.3 BAR)
620 4XXX 160-235 PSI (11-16.2 BAR)
620 5XXX 260-360 PSI (18.25 BAR)
620 7XXX 120-185 PSI (9.0-12.8 BAR)
MODEL NUMBER OUTLET PRESSURE (With Optional Line Regulator
620 3XX8 235 PSI (16 BAR)
620 4XX8 545 PSI (37.6 BAR)