Swagelok Changeover SCO User manual

Swagelok®
Changeover
(SCO)
User Manual

SCO User Manual
2
Content
SCO User Manual
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Congurations . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
System Startup . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Reference Instruction Documents. . . . . . . . . . . . . . . . .18
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . 19

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Swagelok®Changeover
(SCO)
Introduction
A Swagelok®changeover (SCO) is a special type of primary gas control system, pre-engineered
for applications where the continuous supply of gas is critical. When one source is depleted below
a selected changeover pressure, the continuous gas delivery system automatically switches to a
back-up supply. The depleted source can then be changed, in-line, without downtime.

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Congurations
The SCO is available with captured or noncaptured inlet vent and relief valve options. See the SCO section of the Gas Distribution
Systems, Application Guide, MS-02-486, for additional information.
Configuration 1: No Outlet Regulator, Relief Valve, Gauge, and Noncaptured Inlet Valve
Changeover
Lever Handle
Relief Valve
Outlet Isolation Valve
Outlet Gauge (PI)
Inlet Gauges (PI)
Inlet 1
(primary source)
Inlet 2
(secondary source) Noncaptured Vent
Bleed Valve Inlet 2
Inlet Inlet
Outlet
PI
PI
PI
Configuration Symbols
Check
Valve
Pressure
Gauge Regulator
Bleed
Valve
PI
Relief
Valve
Ball Valve
Needle
Valve

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Configuration 2: Outlet Regulator, Relief Valve, Gauge, and Captured Inlet Vent
Relief Valve
Outlet Gauge (PI)
Outlet Isolation Valve
Inlet Gauges (PI)
Captured Inlet
Vent Valves
Inlet 1
(primary source)
Inlet 2
(secondary source)
Outlet Regulator
InletInlet
Outlet
PI
PI
PI

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Mounting
The SCO must be mounted to a vertical face or wall and utilize all four (4) mounting slots for proper function. Mounting slots are
designed for 1/4 in. or 6 mm fasteners. Approximate weight of the SCO is 20.4 lb (9.3 kg).
Dimensions
Dimensions, in inches (millimeters), are for reference only and are subject to change.
NOTE: Weight will vary based on options ordered.
13.6 (345)
overall height
10.85 (275)
4.94 (125)
9.88 (251)
centerline-to-centerline
of mounting slots
1.25 (31.8)
0.50 (12.7)
0 . 2 8 ( 7.1)
3.88 (98.6)
10.0 (254)
5.50 (140)
9.36 (238)
0.44 (11.2)
10.75 (273)
2.34 (59.4)

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Installation
1/4 in. and 6 mm SCO systems have fractional or metric Swagelok tube ttings for all internal system connections. For metric
systems when an R3A series is specied, refer to the supplied data sheet for outlet connection type and size for country/
regional-specic relief valve. For systems with a captured inlet vent, a needle valve will be used with a 1/4 in. NPT female end
connection (illustrated below). For noncaptured inlet vent systems, a bleed valve is used to vent to atmosphere.
• CAUTION Position the bleed valve so that system uid is directed away from operating personnel. Always
open bleed valves slowly. Operating personnel must take suitable measures to protect themselves
from exposure to system uids.
• CAUTION Do not allow any thread sealant to enter the regulator or uid stream.
Install the Swagelok tube ttings according to the Tube Fitting Instructions for 1 in. (25 mm) and smaller ttings, MS-12-01.
Relief Outlet Connection
Outlet Isolation Valve
Captured Inlet
Vent Valves
Inlet 1
(primary source)
Inlet 2
(secondary source)
Captured Inlet Vent
Valves Connection

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Relief Outlet Connection
Outlet Isolation Valve
Captured Inlet
Vent Valves
Inlet 1
(primary source, changeover handle
in up position)
Inlet 2
(secondary source, changeover
handle in up position)
Captured Inlet Vent
Valves Connection
Inlet Gauges (PI)
Outlet Regulator
Outlet Gauge (PI)
Changeover
Lever Handle
System Startup
• CAUTION Swagelok ball valves are designed to be used in a fully open or fully closed position.
• CAUTION Valves that have not been cycled for a period of time may have a higher initial actuation torque. For
valves not actuated for a period of time, initial relief pressure may be higher than the set pressure.
• CAUTION A packing adjustment may be required periodically for needle and ball valves to increase service life
and to prevent leakage.
• CAUTION Some system applications require relief valves to meet specic safety codes. The system designer
and user must determine when such codes apply and whether these relief valves conform to them.
Country/Regional standard relief valves are to be maintained in accordance with local rules and
regulations of the country in which they are installed.
• CAUTION Swagelok proportional relief valves should never be used as ASME Boiler and Pressure Vessel Code
safety relief devices.
• CAUTION Swagelok proportional relief valves are not “Safety Accessories” as dened in the Pressure Equipment
Directive 2014/68/EU.
1. Ensure the changeover lever handle is in the
correct orientation, coinciding with the desired
primary bottle source. The black arrow on the
handle hub will point to the primary bottle source.
2. Verify the inlet vent valves are CLOSED.
3. Verify the outlet isolation valve is CLOSED
(where applicable).
4. Supply bottle pressure to both inlets.
5. Verify the inlet gauges are reading correct pressures.
6. Set the outlet regulator (if present) to desired outlet pressure.
7. Verify the relief valve is not relieving pressure.
8. Open the outlet isolation valve to begin system ow (if
applicable).
9. Adjust outlet pressure by turning the handle on the outlet pressure
control regulator (if present) while the system is owing.

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Operation
The primary gas source of the SCO system is indicated by the changeover handle arrow direction. As the primary gas source
depletes and its pressure equals the secondary source regulator outlet pressure setting, the changeover will occur. The system
will then automatically start pulling from the secondary gas source, supplying an uninterrupted ow downstream.
Note: Due to the regulator orientation, turning the changeover lever handle will increase the outlet pressure setting of the
regulator the arrow will be pointing to after the switch (the “new” primary gas source.) It also decreases the outlet pressure
setting of the regulator the arrow was pointing to prior to the switch (the “new” secondary/depleted gas source.)
• CAUTION Swagelok proportional relief valves are not “Safety Accessories” as dened in the Pressure
Equipment Directive 2014/68/EU.
• CAUTION Do not use the regulator as a shutoff device.
1. To change the primary gas source from the left-hand (LH) source to the right-hand (RH) source, pull the changeover lever
handle from the upward position (12 o’clock) to the downward position (6 o’clock).
Note: The primary gas source changeover regulator is set to a slightly higher outlet pressure than the opposing (secondary)
gas source, establishing the supply for the downstream system. Refer to Setting the Regulator Changeover Pressure.
2. To change out a depleted gas bottle, turn the changeover lever handle fully to its opposing position (i.e., up/down),
reversing the arrow direction. This designates the opposing source as the primary gas source. The depleted gas bottle can
now be safely isolated, vented, and removed, and a full bottle can be installed.
When the replacement of the depleted gas bottle is complete, it is best to allow the SCO to continue depleting the newly
in-use gas source rather than manually switching to the new bottle early. This practice will ensure the secondary gas
source is full when needed.
Note: When the SCO is used as a gas bottle backup to a large gas store such as a gas generator, typically Inlet 1 is connected to
the bulk storage of the generator and Inlet 2 is connected to an emergency backup gas bottle. In these applications, the handle
should be switched back to the bulk storage supply from the backup as soon as practical.

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Maintenance
Changeover Regulator Port Congurations
The illustration below is a reference for the user on the changeover regulator port locations. When a regulator has been removed for
service, use the illustration below as a reference for changeover port locations when assembling the left-hand (LH) and right-hand
(RH) regulators to their respective mounting brackets.
High-Pressure (HP) Ports Are Shown in Red. Low-Pressure Ports Are Shown in Blue.
The Regulators Are E-Pattern.
Changeover Handle Assembly
To decouple the changeover regulators as required for disassembly from the main panel or during the setting of changeover
pressure, the set screw in the hub of the handle assembly must be loosened to allow the hub and shaft to slide apart. Use the
illustration below to guide disassembly of the changeover handle assembly.
LH
LP
RH
LP
HP
HP
Hub
Set Screw

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Setting the Regulator Changeover Pressure
Follow these instructions when either of the changeover regulators need to be serviced, replaced, or reset to ensure the
regulator changeover pressure setting is correct and the LH and RH regulators are assembled in the proper orientation.
1. Establish the requested changeover pressure from the ordering number.
2. Use the 7 mm hex on the end of the stem to set the regulator to the desired changeover pressure.
3. For the LH regulator only, once the desired pressure is reached, rotate the stem clockwise an additional half turn (180°
of rotation).
4. Mark the end of the stem with a line at the bottom. This will allow you to conrm nothing has moved after screwing on
the hub.
HP Gauge
HP Inlet
HP Vent Valve
7 mm Hex
LP Outlet/
Changeover Set Point
Stem

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11. Set RH regulator by following steps 1 through 4. It is imperative that once the set point is reached it is held by ensuring the stem
does not move. Do NOT add half a turn increase or adjust the set point in any way on the RH regulator, as doing so will result in
gas being drawn from both bottles. It may be easier to do this with the LH regulator removed from the back plate.
12. Fit the M10 × 1 mm nut onto the stem, ensuring the stem does not move. Tighten nut all the way to the body. Then turn nut
slightly to ensure the stem will not move when the shaft is tted. Do not overtighten the nut.
13. Screw the machined shaft onto the regulator stem, ensuring the stem does not rotate.
5. Slowly and without changing the set pressure, screw on the machined changeover SCO hub to the LH regulator. Stop the
hub around 5/32 in. (4 mm) before contacting the regulator body. The changeover lever handle must be pointed toward the
top of the panel.
6. Screw the regulator handle lock nut (M10 x 1 mm) back onto the regulator stem.
7. Tighten the M10 nut all the way down inside the SCO hub. Tighten while holding the changeover lever handle in place
pointed towards the top of the panel. The changeover lever handle must point towards the outlet of the panel at all times.
8. The regulator set point should remain unchanged after tightening (a slight change within +0.5 bar/7 psig is acceptable).
Visually verify that the stem has not rotated by checking the location of the mark placed in step 4.
9. Ensure the SCO hub rotates through its full movement of 180 degrees. The handle should rotate from 12 o’clock to 6 o’clock
freely without the SCO hub hitting the body or slipping on the shaft.
10. The LH regulator is now set.
M6 × 1 Bolt
1/4 in. × 20 Bolt
M10 Retaining Unit
From KPR Handle
SCO Hub
Gap Between Hub and Cap
Changeover
Lever Handle
Machined Shaft Stem

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14. Reassemble the LH regulator and bracket to the main panel mounting holes. Slide the shaft into the hub.
15. The shaft should be adjusted on the stem so engagement allows for the regulator bracket to sit at and parallel to the
main panel.
16. Thread the shaft onto the regulator stem to achieve engagement of the shaft and hub, ensuring the regulator stem does
not rotate. The shaft should extend past the set screw hole.
17. Once this engagement has been set, tighten the stem nut to the shaft without the stem rotating. This locks the shaft
to the stem. Use soft grips to hold the shaft in place as you tighten the stem nut.
18. Check that the hub and shaft are aligned.

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19. Connect the hub and the shaft by tightening the set screw in the hub, with the handle lever at the 12 o’clock position. The
handle should always be pointing to the top of the panel (12 o’clock).
20. Mark the hub and shaft. Cycle the changeover valve several times to ensure smooth operation. Check to ensure there is no
slippage between the hub and shaft.
21. Reconnect all tubing and end connections.
Changeover Valve

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Outlet Regulator Mounting
The outlet regulator is an L-Pattern KPR series regulator mounted in the orientation shown. The regulator is assembled to the
mounting bracket with two No. 10-32 at head cap screws. The screw heads are recessed on the rear of the bracket so it
can assemble to the main panel ush and without interference. To remove the regulator, the 1/4 in. or 6 mm button head cap
screws must be loosened to remove the mounting bracket and access the regulator mounting screws.
LP
(Relief Valve)
LP
(Gauge)
LP
(Outlet)
HP
(Inlet)
Second Stage KPR L-Pattern Port Orientation KPR Regulator and Bracket Mounting
Flat Head Cap Screw:
No. 10-32 × 3/8 in. Long

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Outlet Isolation Valve Mounting
• WARNING Before removing valve from service, to avoid personal injury, you must:
• Depressurize the system
• Cycle the valve
• Purge system to remove any residual system media left in valve
The illustrations below identify all outlet isolation selections paired with their respective mounting brackets. To remove a valve
from the panel, rst unscrew the 1/4 in. or 6 mm button head cap screws to remove the bracket from the main panel. The 1/4 in.
or 6 mm Swagelok tube ttings can then be loosened, and the valve and bracket are removed as a subassembly.
1/4-Turn Ball Valve
Multiturn Needle Valve
1/4-Turn Ball Valve (lockable)
No Outlet Isolation Valve
2× B.H.C.S.:
1/4-20 UNC × 3/8 in. Long
M6 × 1.0 × 10 mm Long
4× Set Screw:
No. 10-32 × 5/16 in. Long
M5 × 0.8 × 8 mm Long
2× B.H.C.S.:
1/4-20 UNC × 3/8 in. Long
M6 × 1.0 × 10 mm Long
2× B.H.C.S.:
1/4-20 UNC × 3/8 in. Long
M6 × 1.0 × 10 mm Long
2× B.H.C.S.:
1/4-20 UNC × 3/8 in. Long
M6 × 1.0 × 10 mm Long

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Maintenance by System Component
System Component Replacement Ordering Information
Proportional relief valve (R3A series) Proportional Relief Valves, R Series, MS-01-141
Swagelok tube fitting Gaugeable Tube Fittings and Adapter Fittings, MS-01-140
Needle valve – flow indicator
(1/4 in. systems – M1 series) Variable Area Flowmeters, G Series and M Series, MS-02-346
KPR series regulator Pressure Regulators, K Series, MS-02-230
D series needle valve Nonrotating-Stem Needle Valves, D Series, MS-01-42
Ball valve (40G or 40 series) One-Piece Instrumentation Ball Valves, 40G Series and 40
Series, MS-02-331
Pressure indicator (PGI series,
C model)
Pressure Gauges, Industrial and Process, PGI Series, MS-02-
170
Check valve (CP/CPA and CH series) Check Valves, C, CA, CH, CP, and CPA Series, MS-01-176
BV series bleed valve Bleed Valves and Purge Valves, MS-01-62

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Swagelok Tube Fitting Instructions for 1 in (25 mm) and smaller ttings, MS -12-01
40G Ball Valve Packing Adjustment, MS-INS-40G
R3A Series Externally Adjustable Relief Valve Maintenance Instructions, MS-CRD-0013
Service Instructions, CH Series Check Valve, MS-CRD-0025
CA and CPA Series Check Valve Cracking Pressure Adjustment, MS-CRD-0047
D Series Maintenance Instructions, MS-INS-DK-1
Pressure-Reducing Regulators, KPR Series Maintenance Instructions, MS-CRD-KPRMAINT
Reference Instruction Documents

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Troubleshooting
Symptom Cause Remedy
HP inlet pressure gauge
shows no (or low)
pressure.
There is an obstruction upstream
of the SCO.
Check that flow is passing through the inlet subassemblies
by checking inlet vent needle/bleed valve.
There is no process pressure. Check that the supply line is pressurized.
The inlet vent valve is open. Close the vent valve.
LP outlet gauge shows
no (or low) pressure.
Bottles are empty. Change bottles.
Outlet regulator set to zero outlet
pressure. Adjust regulator outlet pressure.
Relief valve is set at too low of a
pressure.
Check relief valve set point and outlet regulator pressure
setting. If relief valve needs to be reset, contact your
authorized Swagelok sales and service center.
Outlet regulator damaged. Inspect, repair, and/or replace regulator.
LP outlet gauge shows
high pressure.
Regulator creep. Inspect, repair, and/or replace regulator.
Pressure gauge is damaged. Inspect, repair, and/or replace gauge.
Additional pressure source
downstream in system. Identify and correct system malfunctions.
Changeover function not
operating properly.
Changeover handle assembly has
slipped.
Check alignment marks on changeover handle hub and
shaft assembly. Refer to maintenance section.
Secondary source
pressure is dropping/
both sources draining
simultaneously.
Regulator creep. Inspect, repair, and/or replace regulator.
Both source bottle pressures are
below the changeover point. Replace both source bottles.
Inlet vent valves leaking. Inspect, repair, and/or replace inlet vent valve.
Inlet vent valve open. Close inlet vent valves.
Relief valve is relieving
pressure.
Incorrect relief valve set point. Check relief valve set point. If relief valve needs to be reset,
contact your authorized Swagelok sales and service center.
Regulator creep. Inspect, repair, and/or replace regulator.
Additional pressure source
downstream in system. Identify and correct system malfunctions.
For any symptoms not identied in the above table, please contact your authorized Swagelok sales and service center.

Safe Product Selection
When selecting a product, the total system design must
be considered to ensure safe, trouble-free performance.
Function, material compatibility, adequate ratings,
proper installation, operation, and maintenance are the
responsibilities of the system designer and user.
Warranty Information
Swagelok products are backed by The Swagelok Limited
Lifetime Warranty. For a copy, visit swagelok.com or contact
your authorized Swagelok sales and service center.
Swagelok — TM Swagelok Company
© 2021 Swagelok Company
July 2021, Rev-
MS-13-336
•WARNING
Do not mix/interchange Swagelok products or
components not governed by industrial design
standards, including Swagelok tube fitting end
connections, with those of other manufacturers.