Concoa 637 Series User manual

Before Installing or Operating, Read and Comply with These Instructions
ADI 3208-B
Certified ISO 9001
637 Series
AutoSwitch
System
For use with
Liquid Cylinders and High
Pressure Gases
INSTALLATION AND OPERATION INSTRUCTIONS
Controls Corporation of America
1501 Harpers Road • Virginia Beach, VA 23454
Telephone [phone] or 757-422-8330 • Fax [phone]
www.concoa.com
March 2022
Revision B

THIS PAGE INTENTIONALLY LEFT BLANK

The 637 Series AutoSwitch is an automatic switchover system designed to provide a continuous
supply of industrial gas. This unit may be configured with or without the connections to connect to
both high pressure and liquid cylinders. The primary bank (left side) of the AutoSwitch system is
configured for use with liquid cylinders (pressure up to 600 PSI). The reserve bank (right side) is
configured for high pressure cylinders filled up to 3000 PSI (207 bar). The standard AutoSwitch
system will maintain a regulated line pressure within the values shown in the table below:
MODEL
RANGE
637 2XXX
0-40 PSI (0-2.8 BAR)
637 3XXX
0-100 PSI (0-7 BAR)
637 7XXX
0-150 PSI (0-10.5 BAR)
The continuous working inlet pressure on the primary bank (liquid cylinder) must be above 270 PSI
for the system to operate properly. When the primary bank falls below this value, gas will be pulled
from the reserve side.
The 637 Series is designed to be used in conjunction with CONCOA’s Altos 2 Remote Alarm *. It
cannot be connected directly to AC line voltage. In addition to a Power Indicator light, 637 Series
AutoSwitches are equipped with LED status lights to indicate the condition of the gas cylinders. A
green indicator light signifies a “Normal” condition while a red light indicates an “Alarm” (gas cylinder
empty) condition. The 637 Series AutoSwitch systems also include a strain relief on the bottom
through which wiring can be connected to an internal circuit board and to a remote alarm such as
CONCOA’s Altos 2 *.
Figure 1
1
DESCRIPTION OF PRODUCT

INTENDED USE OF PRODUCT
The brass 637 Series AutoSwitch system is intended for use in industrial, non-corrosive gas applications.
Please note the safety information shown in the later sections.
USER RESPONSIBILITY
The User of this equipment should follow all installation and operation instructions when using this
equipment. It is recommended that the user review all safety precautions listed in the safety section of this
manual .
This equipment must be checked periodically. Improperly working equipment should not be used. Broken,
worn, distorted, contaminated, or missing components should be replaced immediately.
CUSTOMER ASSISTANCE
In the event of equipment failure, call the CONCOA Customer Assistance Line: 1-800-225-0473. 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, flow rate, environmental
conditions, and gas service.
SAFETY
Carefully read and comply with these instructions before installing or operating any high pressure gas
manifold. These manifolds are designed, manufactured, and tested to conform to industry standards for
safety for high pressure gas manifolds for a maximum inlet pressure of 3000 PSI (200 bar) on the reserve
(right) side. The primary (left) side is rated up to 600 PSI (40 bar).
Always observe the following safety practices:
√ 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 prevent the cylinder valve from
breaking off at the top of the cylinder 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.
√ Keep all cylinders away from any source of high temperature (not over 120° F, 50° C) or possible fire
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.
√ No smoking should be permitted near oxygen, nitrous oxide, flammable gases, or flammable 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 lift gas cylinders with a magnetic lifting device.
√ Never use an open flame 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.
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√ Always install a blind gland and nut on any manifold inlet fitting if no cylinder is connected to the fitting before
opening any cylinder valve which is already connected to the manifold.
√ 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 they are full before connecting to a manifold.
√ NOTE: Use of PTFE lined pigtails for oxygen installations is not recommended unless they are equipped with a
Distance Volume Piece (DVP). Components in the manifold system can create a dead end passage. The
combination of a dead end passage coupled with a rapid pressurization may lead to adiabatic compression of
the contained oxygen and subsequent failure of the pigtail by ignition.
√ All gas distribution piping systems must meet appropriate industrial standards for the intended service, and
must be thoroughly cleaned before using.
Comply with all safety rules and precautions of the following:
1. American National Standards Institute standard Z49.1 or Safety in Welding and Cutting, American
Welding Society, 2501 NW Seventh Street, Miami, FL 33125.
2. N.F.P.A. Standard 51, Oxygen-Fuel Gas Systems for Welding and Cutting, N.F.P.A., 470 Atlantic
Avenue, Boston, MA 02210.
3. N.F.P.A. Standard 51B, Cutting and Welding Processes, (see Address in #2)
4. CONCOA Publication ADE 872, Safety Precautions in Welding and Cutting.
5. Local ordinances.
6. O.S.H.A.
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 C-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.
3

INSTALLATION
The site chosen for the installation of the system shall be level, well ventilated, and at a safe
distance from sources of flames, sparks, and excessive heat. The system should not be placed in
an area that may subject it to damage from passing trucks, cranes, or other heavy machines. Any
oxygen system must not be installed under shafting, belting, or other places where oil can drip on it.
Refer to the Manifold ADI for Manifold installation instructions.
a. Be sure to consider all factors when selecting materials.
b. Do not use oil or grease on fittings.
c. Be sure that all fittings are secure and leak tight. PTFE tape must be used on pipe threads.
d. Relief Valve: The purpose of the relief valve is to protect the AutoSwitch system and its
components only (Figure 2). If there is pressure sensitive equipment downstream of the
AutoSwitch system, it is recommended that an appropriately sized relief valve be installed in
the line to protect this equipment.
e. Purge Devices: These devices can be purchased as accessories. Purge devices are used to
remove toxic, corrosive, or flammable gases from the customer’s system to a safe discharge
area. This is particularly helpful when an internal problem occurs (such as regulator
malfunction).
Figure 2
4

Follow Compressed Gas Association, OSHA and all applicable local codes. Manifolds should not be
placed in locations where the temperature will exceed 102°F (49°C) or fall below 0°F (-18°C).
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.
1. Determine and mark the vertical center line for installation of the AutoSwitch Console. (Figure 3).
2. Measure from the floor 72” in height at this center line. With the AutoSwitch mounting bracket at
this height, the manifold header will be approximately 66” from the floor. Using a level, mark a
horizontal line at this point extending approximately 10 inches to the left and right of center.
3. Remove the mounting bracket from the rear of the AutoSwitch Console by removing the nuts at
the bottom of the bracket. Place the upper edge of the bracket cross-member on the horizontal
line so that it is centered with the vertical line. Holding the bracket with the slotted extensions
away from the wall, mark the location of the two mounting bolts (Figure 4)
4. Using appropriate hardware based on wall construction, anchor the mounting bracket to the wall
(Figure 4).
5. Place the AutoSwitch system so that the mounting bracket slots align with the shoulder nuts.
With the AutoSwitch box hanging on the shoulder nuts, align the retaining bolts so that they
protrude through the bracket. Replace the mounting nuts that were removed in step 3.
Figure 3 - Center-line Mark Figure 4 - Mounting Bracket
Figure 5 - Console and Mounting Bracket
5
WALL-MOUNTING
Retaining Nuts
Mounting Bracket
Shoulder Nuts
Console
Mounting Screws

If a floor stand option is selected, the AutoSwitch is mounted to two of the rails of the stand (Figure 6).
Refer to the Manifold ADI instructions for details on mounting the floor stand.
Figure 6 –Example of Floor Stand Mounting
6
FLOOR MOUNTING

General:
Use an open-end wrench, not a pipe wrench, to install accessories to the AutoSwitch system. ALWAYS
hold the bulkhead fitting with a wrench when installing the accessories to the AutoSwitch system.
Do not allow the bulkhead fitting to turn; otherwise, connections inside the box may be loosened.
NPT connections require the use of PTFE tape on the threads to make a gas tight seal (See Figure 7.).
CONCOA uses PTFE tape on all of its NPT connections. Follow these rules when using PTFE tape.
a. Do not use oil or grease on fittings. This is especially important for oxidizing gas service.
b. PTFE tape must be used on NPT threads to ensure a gas tight seal. Avoid impinging on the gas stream. On
stainless steel connections, PTFE tape also helps to prevent the connections from galling together when tightening
or loosening.
c. Before applying PTFE tape, inspect the NPT threads, and, if necessary, clean the fitting to remove any dirt or
thread sealant that remains on the threads.
d. Start the PTFE tape on the first thread leaving a slight section of the chamfer exposed as shown in Fig. 7. Make
sure the tape does not overlap the end of the fitting.
e. As tape is wound in the direction of the thread spiral, pull tightly on the end of the tape so that the tape conforms
to the thread.
f. Apply at least 2 but no more than 3 layers of tape to the threads, and cut off excess tape.
g. Press the end firmly into the threads.
Figure 7 - Pictorial View of Tape Seal
Installing the inlet connection:
WARNING: The left bank of the AutoSwitch system has a maximum working pressure of 600 PSI. Do not
install high pressure cylinders to the left bank of the AutoSwitch system.
When using a Maniflex system:
The ½ male NPT end of the manifold connector will need to be installed in the inlet port of the AutoSwitch.
The other end of the manifold connector will be connected to the starter block of the 528 series Maniflex
system. Please follow the instructions provided with the Maniflex system when installing and operating the
manifold system.
Figure 8 –Manifold Connection
7
INLET AND OUTLET CONNECTIONS

Connecting to a cylinder:
1. Before removing the cylinder cap, move the cylinder of gas to the work site:
a. Secure cylinder to the floor, 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. Do not force. Tightening the nut onto the cylinder connection should be easy. If it is not, 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 fittings, as it may contaminate pure gases, or
create a fire hazard.
Installing the Outlet Connection:
The AutoSwitch system has the outlet connection at the top of the box. The connection is a 1/2”
NPT Female connection. Connect tubing to the AutoSwitch that is compatible with the application
and iscapableof handling the pressure required.
8

Pressurizing the system for the first time (non-manifold use):
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 pigtails are secured before pressurizing. Turn the line regulator
knob counterclockwise until the knob stops turning.
3. When first 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.
4. Keep the hand wheel or wrench on the open cylinder valve at all times to allow prompt
emergency shut-off.
5. Inspect all connections for leaks, and fix 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 cannot be used, 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. Never attempt to fix a leak under pressure. If leaks are detected,
depressurize the system and retighten the connection. Begin again at step 3.
WARNING: While CONCOA assembles the AutoSwitch system components to exacting leak-tight
standards, the customer should also inspect for any loosening of internal parts that may occur in
shipping or installation by completing the pressure decay test detailed above. If all external leaks
have been found, corrected, and the system still indicates a leak, disassemble the front cover
from the AutoSwitch after removing the eight screws shown below. Check for leaks on the
system’s fittings as described above.
6. Slowly turn the line regulator knob clockwise. This will increase the pressure of the line. Adjust
to the desired working pressure and again check for leaks using the methods described above.
Screws
Figure 9
9

MAINTAINENCE
As the gas in the primary side (liquid cylinders) is depleted, there will not be a drop in gas pressure on
the left gauge until the cylinders are empty. When the inlet pressure drops to the pressure setting of
the reserve side regulator, flow will begin from the reserve cylinder. The inlet pressure on the primary
side will stabilize at 215-235 PSI. This is called a changeover. At this point, the gas pressure on the
reserve side will drop. This indicates that it is time to change the liquid cylinders on the primary side.
Before removing the cylinder, be sure to close the cylinder valve and any other valves that connect the
cylinder to the system. Remove the depleted cylinder(s) and replace with a full cylinder(s). Note: While
changing cylinders on one side, there will be no interruption in flow.
WARNING: After several changeover cycles, it is possible that the reserve cylinder may not have
sufficient reserve capacity. Periodically check the pressure of the reserve high pressure cylinders.
Maintain enough gas in the high pressure cylinders so that when a changeover occurs, the system will
not run out of gas before the liquid cylinders are replaced.
Adjusting the alarm set point does not affect the switchover point of the AutoSwitch. The alarm is used
to provide an audible and visual warning that a changeover is about to occur. If the nearly depleted
cylinders are changed when the alarm LED’s illuminate, the cylinders will not be as empty as if the
actual changeover had occurred. Slide the red tab seen on the inlet gauge to adjust the alarm set
point. The lowering of the alarm set point pressure may cause the alarm to not work properly. When
adjustments are made, check the function of the system. Pressurize the system and shut off the inlet
pressure to both sides. Allow the inlet pressure to decrease by allowing a small flow (50 CFH).
Observe both inlet gauges. When the left bank is low (below the set point on the gauge), the red LED
will illuminate. Make sure the left red LED illuminates before the pressure on the opposite side starts to
decrease. Allow the system inlet pressures to decrease further until the right red LED illuminates. This
should happen before both inlet pressures start falling together.
Figure 10
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. The pigtail check valve should also be
checked for leaks when a depleted cylinder is removed. Note: the system inlet and pigtail should be
pressurized when checking for leaks. At no time should the preset regulators’factory settings be
changed. 10
OPERATION

TROUBLESHOOTING
11
Symptom
Cause
1. Gas leakage at the line regulator outlet when the
adjusting knob of the line regulator is completely
backed out.
2. With no flow 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 of regulator).
4. Gas leakage from any joint.
5. Excessive drop in working pressure with
regulator flowing gas.
6. Gas leakage from relief valve.
7. Gas leakage from any gauge.
8. Gauge does not return to zero when not under
gas pressure.
9. Gauge does not consistently repeat the same
reading.
Regulator(s) have malfunctioned. Replace or repair
1. Switchover system seems to be using gas from
the primary and reserve cylinders simultaneously
(pressure is decreasing on both inlet gauges at
the same time)
1. Observe the inlet pressure. It may be
necessary to do this during times of the
heaviest use. If the inlet pressure is less than
the value listed below, replace the high-
pressure cylinders:
270 PSI (19 BAR)
If the inlet pressure increases significantly
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.
1. Inlet Gauges not reading pressure
1. Check that the valves on the cylinders are
opened.
2.If using a manifold system, check that the valve
on the manifold is opened.
1. Power light is not on.
1. Check that the remote alarm is powered on.
2. Check that the cable between the AutoSwitch
and the remote alarm is wired correctly.
3. For models with a circular connector on the
AutoSwitch, check that the cable connectors are
properly plugged in at both ends.

TROUBLESHOOTING (cont.)
Symptom
Cause
1. Status lights are not lighted
1. Check that the remote alarm is powered on.
2. Check that the cable between the AutoSwitch
and the remote alarm is wired correctly.
3. For models with a circular connector on the
AutoSwitch, check that the cable connectors
are properly plugged in at both ends.
1. Green status light(s) are lighted when the
pressure is below the set point on the gauges
2. Red status light(s) are lighted when the pressure
is above the set point on the gauges
1. Cable to remote alarm wired incorrectly. Follow
instructions in remote alarm instruction manual
to correct the problem.
1. With full tank pressure, red alarm light(s) are on.
1. Cable to remote alarm wired incorrectly. Follow
instructions in remote alarm instruction manual
to correct problem.
SERVICE
A Unit that is not functioning properly should not be used and should be returned to CONCOA for
service. A Return Material Authorization (RMA) number must be issued for any product returned to
CONCOA for service. Please contact a Customer Service Representative at 1-800-225-0473 to
receive this number. You will be asked to provide:
1. Model Number
2. Gas Service
3. Inlet pressure and type of gas supply
4. Outlet pressure
5. Approximate gas useage.
When shipping product back to CONCOA for repair, the following steps should be followed:
1. Package the product sufficiently to prevent damage. If possible return product in its orginial
packing.
2. Include RMA number on the outside of the carton.
3. Ship prepaid.
4. Include a written description of the problem you encountered with the product inside the package.
5. Include a statement of the gas service the product was used in.
6. Purge all equipment before shipping to protect the transporter and service personnel.
Purging is especially important if the equipment has been in hazardous or corrosive gas
service.
12

Warranty Information
This equipment is sold by CONTROLS CORPORATION OF AMERICA under the warranties set
forth in the following paragraphs. Such warranties are extended only with respect to the purchase of
this equipment directly from CONTROLS CORPORATION OF AMERICA or its Authorized
Distributors as new merchandise and are extended to the first Buyer thereof other than for the
purpose of resale.
For a period of one (1) year from the date of original delivery (90 days in corrosive service) to Buyer
or to Buyer’s order, this equipment is warrantied to be free from functional defects in materials and
workmanship and to conform to the description of this equipment contained in this manual and any
accompanying labels and/or inserts, provided that the same is properly operated under conditions
of normal use and that regular periodic maintenance and service is performed or replacements
made in accordance with the instructions provided. The foregoing warranties shall not apply if the
equipment has been repaired: other than by CONTROLS CORPORATION OF AMERICA or a
designated service facility or in accordance with written instructions provided by CONTROLS
CORPORATION OF AMERICA, or altered by anyone other than CONTROLS CORPORATION OF
AMERICA, or if the equipment has been subject to abuse, misuse, negligence or accident.
CONTROLS CORPORATION OF AMERICA’s sole and exclusive obligation and Buyer’s sole and
exclusive remedy under the above warranties is limited to repairing or replacing, free of charge, at
CONTROLS CORPORATION OF AMERICA’s option, the equipment or part, which is reported to its
Authorized Distributor from whom purchased, and which if so advised, is returned with a statement
of the observed deficiency, and proof of purchase of equipment or part not later than seven (7) days
after the expiration date of the applicable warranty, to the nearest designated service facility during
normal business hours, transportation charges prepaid, and which upon examination, is found not to
comply with the above warranties. Return trip transportation charges for the equipment or part shall
be paid by Buyer.
CONTROLS CORPORATION OF AMERICA SHALL NOT BE OTHERWISE LIABLE FOR ANY
DAMAGES INCLUDING BUT NOT LIMITED TO: INCIDENTAL DAMAGES, CONSEQUENTIAL
DAMAGES, OR SPECIAL DAMAGES, WHETHER SUCH DAMAGES RESULT FROM
NEGLIGENCE, BREACH OF WARRANTY OR OTHERWISE.
THERE ARE NO EXPRESS OR IMPLIED WARRANTIES WHICH EXTEND BEYOND THE
WARRANTIES HEREINABOVE SET FORTH. CONTROLS CORPORATION OF AMERICA
MAKES NO WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE WITH RESPECT TO THE EQUIPMENT OR PARTS THEREOF.
13

ADI 3208-B
Certified ISO 9001
Controls Corporation of America
1501 Harpers Road Virginia Beach, VA 23454
Telephone [phone] or 757-422-8330 •Fax [phone]
www.concoa.com