Swagelok TBVS8 User manual

TBVS8 Back-Pressure Regulator User Manual
Read the complete manual before installing and using the regulator.

2
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.
WARNING
•Users must be trained and equipped for the handling, use, and servicing of pressure
products and systems.
•Users must contact their gas or liquid supplier for specific safety precautions and
instructions.
•Gaseous media should be free of excessive moisture to prevent icing at high flow.
•Always wear the appropriate protective clothing, including safety glasses, gloves, etc., if
required.
•Follow the applicable safety and maintenance procedures.
•Obey specific local regulations.
•Do not exceed the maximum inlet and outlet pressure rating of the product or its
accessories.
•Operate within the temperature limits and any other conditions specified for the product.
•Do not drop or damage the product in any other way. This may negatively affect the
performance of the product which can cause the product to malfunction.
•Venting fluids and gases can be dangerous. Vent to a safe environment away from people.
Ensure adequate ventilation.

3
Contents
Introduction........................................................................................................................................................ 4
Overview.......................................................................................................................................................... 4
Standard Features........................................................................................................................................... 4
Additional Options ........................................................................................................................................... 4
Oxygen Service............................................................................................................................................... 4
Installation.......................................................................................................................................................... 5
Points of Attention Before Installation ............................................................................................................. 5
Installation ....................................................................................................................................................... 5
Operation............................................................................................................................................................ 6
Required Tools for Operation.......................................................................................................................... 6
Points of Attention Before Operation............................................................................................................... 6
Adjusting the Set Pressure.............................................................................................................................. 6
Maintenance....................................................................................................................................................... 7
Required Tools for Maintenance..................................................................................................................... 7
Points of Attention Before Removal from the System..................................................................................... 8
Removal from the System............................................................................................................................... 8
Assembly Reference Data............................................................................................................................... 9
Disassembly.................................................................................................................................................. 12
Points of Attention Before Reassembly......................................................................................................... 12
Reassembly................................................................................................................................................... 13
TBVS8 Series: Standard............................................................................................................................... 13
TBVS8 Series: Factory Set Option................................................................................................................ 13
Testing.............................................................................................................................................................. 14
Seat Leak Test .............................................................................................................................................. 14
Shell Leak Test.............................................................................................................................................. 14
Troubleshooting .............................................................................................................................................. 15

4
Introduction
Overview
- The TBVS8 series are spring loaded back pressure regulators designed for low pressure, high sensitivity
regulation of gases and liquids.
- For pressure and temperature rating information refer to the Tank Blanketing Pressure Regulators, RHPS
Series catalog, MS-02-431.
WARNING
Check that system pressures and temperatures do not exceed those stated on the regulator as
this could result in product failure.
Standard Features
- Bolted construction
- Stainless steel as standard
- Fully serviceable
- Diaphragm sensing
- Millibar control
Additional Options
The regulator is available with the following options:
Factory set (FS) and locked
Oxygen Service
- For more information about hazards and risks of oxygen enriched systems see the Swagelok Oxygen
System Safety technical report (MS-06-13).
- Cleaning and packaging to ensure compliance with product cleanliness requirements stated in ASTM G93
Level C is available. Refer to the Tank Blanketing Pressure Regulators, RHPS Series catalog, MS-02-431,
for additional information.

5
Installation
CAUTION
Do not use the regulator as a shutoff device. A level of leakage across the regulator seat can
occur during normal operation.
Points of Attention Before Installation
This regulator can be equipped with a variety of different options. Before installing the regulator you should
fully understand the functions of the supplied options and the suitability of your particular regulator for the
intended application.
- The preferred mounting position of the regulator is horizontal with the spring housing facing upwards per
Fig 2. Alternative mounting positions may increase the risk of component wear.
- It may be necessary to remove the regulator from the system during maintenance or service. Ensure that
this is possible.
- The regulator is suitable for gases or liquids. Ensure compatibility between the regulator’s materials of
construction and the system media.
Installation
- Verify that the regulator, its connections, and any accessories are undamaged.
- Verify that the regulator and any accessories are suitable for the system operating pressure and
temperature and have suitable connections.
- At the time of delivery any gauge ports may be plugged with blind fittings. Remove these and connect
gauges if desired.
- If inlet/outlet fittings are being used, assemble them to the regulator, per the manufacturer’s instructions,
prior to installing the regulator in the system.
CAUTION
Ensure all upstream tubing/pipework is clean and free from debris. Any swarf, lint, wire, etc. may
damage the regulator, resulting in a seat leak.
- Verify the flow direction of the system and mount the regulator accordingly.
- Securely make the appropriate connections to the regulator in accordance with the procedures
recommended by the connection manufacturer.
- Ensure that the tubing/pipework and the regulator are adequately supported and that there is no stress on
the connections.
- Upstream and downstream shutoff valves should be installed in the system to facilitate servicing,
maintenance, and troubleshooting of the regulator.

6
Operation
Required Tools for Operation
A 19 mm socket is required for changing the set pressure on a standard regulator.
Points of Attention Before Operation
CAUTION
The product can be hot or cold, depending on the environmental temperature and the process
media temperature. Take the necessary precautions before operating or touching the product.
- Once the regulator closes, after being open to flow, the inlet pressure may fall a little under the set
pressure. This is usually referred to as “reseat pressure”. This phenomenon does not indicate a
problem with the regulator.
- An increase in the flow may result in a rise of the set pressure. A decrease in the flow may result in a fall
of the set pressure. This is usually referred to as “accumulation”. This phenomenon does not indicate a
problem with the regulator.
- An increase of the outlet pressure may result in a fall of the set pressure. A decrease of the outlet
pressure may result in a rise of the set pressure. This is usually referred to as “dependency”. This
phenomenon does not indicate a problem with the regulator.
Adjusting the Set Pressure
- The set pressure is the desired outlet pressure of the regulator.
- To set the regulator, ensure that the supply pressure is greater than the required set pressure but does
not exceed the maximum rating of the regulator.
- The regulator must be able to flow in order for it to reduce the outlet pressure.
1. Open any downstream valve.
2. To operate, turn the adjusting screw clockwise to increase the set pressure. Turn the adjusting screw
counterclockwise to reduce the set pressure.
3. Partially open the supply valve to allow the regulator to sense the inlet pressure with minimal flow.
4. Close the supply valve and verify the set pressure by measuring the regulator inlet pressure.
5. Make adjustments to the set pressure as required and repeat steps 3 and 4.
6. To obtain the most accurate set pressure final adjustment must be made while increasing the set
pressure adjustment. If the desired set pressure is exceeded, reduce the pressure below this value then
increase up to it.
7. Once the regulator is set, the supply pressure can be adjusted to its normal working value.
8. Open the supply valve fully to allow full flow during operation.
9. When in operation make any final set pressure adjustments if required.

7
Maintenance
WARNING
Incorrect or improper repair or servicing of this product can cause serious personal injury and
property damage.
- All repairs, servicing, and testing of this product must be performed by competent personnel.
- Following any maintenance of the regulator, it is recommended that the product be tested for operation
and leakage.
- The product should be checked periodically for proper and safe operation. It is the user’s sole
responsibility to determine the frequency of maintenance based on the application.
- To reduce maintenance related system downtime to a minimum, either during commissioning or normal
operation, Swagelok recommends having maintenance kits readily available on site. The need for
maintenance kits is particularly important during the commissioning phase of a system installation due to
residual assembly debris remaining in the system. Such debris can cause a seat leak in the regulator,
resulting in components needing to be replaced.
Required Tools for Maintenance
Smooth-jawed vise
C-ring pliers
6 mm open-ended
wrench
Calibrated torque wrench up
to 30 lbf·ft (40 N·m)
10 mm open-ended
wrench
4 mm hex drive
Lubricant (included in kit):
WL-8②
Krytox® 240 AC③
3 mm hex drive①
17 mm socket
Liquid leak detector
19 mm socket
①Factory set option only
②Standard cleaned assemblies
③ASTM G93 or SC11 cleaned assemblies Table 1

8
Points of Attention Before Removal from the System
- Swagelok recommends removing the regulator from the system for servicing and maintenance.
- Follow all local system safety and maintenance procedures when removing the regulator.
WARNING
Before removing a regulator from the system, to avoid personal injury, you must:
•Depressurize the system.
•Purge the system to remove any residual system media left in the regulator.
•Always vent to a safe environment away from people and ensure there is adequate
ventilation.
CAUTION
Check if the process media is hazardous or toxic. If required, take the necessary safety
precautions to ensure a safe workspace and your personal safety.
CAUTION
The product can be hot or cold, depending on the environmental temperature and the process
media temperature. Take the necessary precautions before operating or touching the product.
Removal from the System
1. Isolate the regulator from all pressure sources by closing all appropriate upstream valves in the system.
2. With the regulator set to the open position (i.e. adjusting screw backed off fully counterclockwise) , open
all appropriate downstream valves to allow pressure to vent from the regulator.
WARNING
Ensure all pressure on the inlet and outlet has been fully vented. The accidental release of
residual trapped pressure can cause serious personal injury.
3. Disconnect and remove the regulator from the system.

9
Assembly Reference Data
Item
Component Name
Kit Type(s)
Torque
lbf·ft (N·m)
Recommended Lubrication
(included in kit per Table 1)
1
Body plug
C1, C2
30 (40)
Lubricate threads
2
Body plug O-ring
B1, B2, C1, C2
3
Seat
A1, B1, C1
4
Seat O-ring
A1. B1, B2, C1
5
Nut
E1
6
Lock washer
E1
7
Body assembly
N/A
8
Stem
A1, A2, B1, C1
Lubricate threads
9
Guide ring
C1
10
Retaining ring
C1
11
Seal housing
C1
12
Seal housing O-ring
B1, B2, C1
13
Diaphragm plate
C1
14
PTFE Diaphragm
B1, B2, C1, C3
15
Diaphragm support
B1, B2, C1, C3
16
Lock washer
C1
17
Diaphragm nut
C1
7 (10)
18
Spring guide
C1
Lubricate recess of top guide only
19
Set spring
C1, C4
20
Spring housing
N/A
21
Cap screw
E1
7 (10)
Lubricate threads
22
Adjusting screw
D1
Lubricate threads
23
FS locking ring①
D1
24
FS locking screw①
D1
3.7 (5)
25
Cover
D1
①Factory set option only Table 2
For more information on RHPS series maintenance kits, refer to the Tank Blanketing Pressure Regulators,
RHPS Series catalog, MS-02-431.

10
TBVS8 Series, Exploded View
Fig 1

11
TBVS8 Series, Section View
Fig 2

12
Disassembly
- The following instructions describe how to fully disassemble the regulator for the purposes of
maintenance and repair.
- Note that not all components listed appear in all regulator configurations.
- Only disassemble the regulator as far as is required to replace the components supplied in the
maintenance kit.
- Discard all components being replaced.
1. Remove the body plug (1) to remove the seat (3), and seat O-ring (4) from the body assembly (7).
2. Remove the cover (25) and ensure that the adjusting screw (22) is backed out and not acting on the set
spring (19). It can be fully removed, if required, by unwinding counterclockwise until it detaches from the
spring housing (20).
3. Loosen the cap screws (21) and remove the spring housing (20).
4. Loosen the diaphragm nut (17) and remove the lock washer (16), diaphragm support (15), PTFE
diaphragm (14), diaphragm plates (13), seal housing (11), and O-ring (12) from the stem (8).
5. Remove the retaining ring (10), guide ring (9) and the stem (8) from the body assembly (7).
Points of Attention Before Reassembly
- Visually inspect all components for abnormal wear or damage. Replace components in case of doubt.
- All parts must remain clean and undamaged before starting assembly.
- Maintenance kit components will be supplied preassembled where practicable to aid reassembly.
- Swagelok recommends replacing all O-rings removed during disassembly.
NOTICE
All threaded components must be lightly lubricated per Table 2 before reassembly to avoid
galling of threads.

13
Reassembly
TBVS8 Series: Standard
1. Secure the body assembly (7) in a vise.
2. Place the seat O-ring (4) onto the seat (3), then insert them both into the body assembly (7).
3. Fit the body plug O-ring (2) into the body assembly (7).
4. Lightly lubricate the body plug threads (1) then thread it into the body assembly (7). Torque to 30 lbf·ft (40
N·m).
5. Insert the stem (8) into the guide ring (9).
6. Insert the guide ring (9) into the body and retain it with the retaining ring (10).
7. Fit the seal housing (11), seal housing O-ring (12), first diaphragm plate (13), diaphragm (14), diaphragm
support (15), and second diaphragm plate (13) onto the stem (8) per Fig 2.
8. Lightly lubricate the stem thread (8) then fit the lock washer (16) and diaphragm nut (17) onto it. Torque
the nut to 7 lbf·ft (10 N·m).
9. Place one of the spring guides (18) and the set spring (19) onto the poppet stem (8).
10. Lubricate the recess of the remaining spring guide (18) then place this into the set spring (19).
11. Cover the spring with the spring housing (20).
12. Lightly lubricate the cap screws (21). Secure the spring housing (20) to the body (7) using the cap screws
(21), washers (6), and nuts (5). Torque to 7 lbf·ft (10 N·m).
13. Lubricate the adjusting screw thread (22) and install into the top of the spring housing (20).
14. Fit the cover (25) into the top of the spring housing (20).
TBVS8 Series: Factory Set Option
1. Follow steps 1 through 13 of the TBVS8 series standard reassembly procedure.
2. Screw the FS locking ring (23) into the spring housing (20) until it contacts the adjusting screw (22).
3. Insert the FS locking screw (24) into the FS locking ring (23) and torque to 3.5 lbf·ft (5 N·m).
4. Follow step 14 of the TBVS8 series standard reassembly procedure.

14
Testing
Swagelok recommends that the regulator be tested for seat and shell leakage to atmosphere. A well
performing regulator will not show any indication of leaking. If any evidence of a leak is identified this must be
rectified. Any damaged components must be replaced.
Seat Leak Test
1. Ensure there is sufficient supply pressure to the regulator to be able to perform the tests.
2. Ensure any downstream shutoff valves are open.
3. Set the regulator to its maximum set pressure then close the supply shutoff valve.
4. Monitor the inlet pressure and/or use liquid leak detector on the outlet port. A drop in inlet pressure over
time or bubbles in the leak detector indicates a seat leak.
Shell Leak Test
1. Set the regulator to the open position (i.e. ensure the actuating stem is fully backed off counterclockwise).
2. Close the downstream shutoff valve.
3. Maintain maximum inlet pressure on the regulator. Measure the outlet pressure to ensure this also reads
the same value.
4. Using liquid leak detector, check for bubbles at the spring housing to body interface, body plug to body
interface and the spring housing weep hole.

15
Troubleshooting
Symptom
Cause
Remedy
Constant leakage from the
outlet before the set pressure is
reached.
A damaged seat and/or stem.
Replace the seat and/or stem.
Leakage around the body plug.
A damaged O-ring.
Replace the O-ring.
Leakage between the body and
the spring housing.
A damaged diaphragm.
Replace the diaphragm.
Insufficient torque on the spring
housing.
Tighten the cap screws per Table 2.
The required set pressure
cannot be reached.
The inlet pressure to the regulator
is not high enough.
Ensure that the inlet pressure to the
regulator is equal to or greater than the
desired set pressure.
The inlet pressure rises too
much when going from a
dynamic to a static situation.
There is too much flow in the
dynamic situation.
A larger regulator or parallel regulator
is required.
Review application flow capacity and
contact your local authorized sales and
service center.
The regulator will not relieve at
the set point.
The stem is sticking.
Replace the stem.
The set point has been
accidentally altered.
Readjust the set point.
The set pressure has changed
without adjusting the set screw.
Changes to the outlet pressure
may result in changes to the set
pressure.
Maintain a constant outlet pressure on
the regulator. See “Points of
Attention Before Operation” about
dependency.
Changes to the flow may result in
changes to the set pressure.
Maintain a constant flow through the
regulator. See “Points of Attention
Before Operation” about
accumulation.
Table 3

Warranty Information
Swagelok products are backed by The Swagelok Limited Lifetime Warranty.
For a copy, visit swagelok.com or contact your authorized Swagelok representative.
Swagelok, Snoop - TM Swagelok Company
Krytox –TM The Chemours Company
© 2018 Swagelok Company
July 2018, RevB
MS-CRD-0168