Spirax Sarco SafeBloc DBB3 User manual

IM-P184-09 CMGT Issue 4 1
1. Safety information
2. General product information
3. Installation
4. Commissioning
5. Operation
6. Maintenance
7. Spare parts
© Copyright 2018
Printed in GB
1849050/3
Spirax SafeBlocTM DBB3 Double Block and Bleed
Bellows Sealed Stop Valve
Installation and Maintenance Instructions
IM- P184-09
CMGT Issue 4

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Safe operation of these products can only be guaranteed if they are properly installed,
commissioned, used and maintained by qualified personnel (see Section 1.11) in compliance with
the operating instructions. General installation and safety instructions for pipeline and plant
construction, as well as the proper use of tools and safety equipment must also be complied with.
Warning
The body/bonnet gaskets (11a and 11b) contain a thin stainless steel support ring which may cause
physical injury if not handled and disposed of carefully.
1.1 Intended use
Referring to the Installation and Maintenance Instructions, name-plate and Technical Information
Sheet, check that the product is suitable for the intended use/application. The product listed below
complies with the requirement of the Pressure Equipment Directive (PED) and carries the
mark when so required. It should be noted that products that are in category 'SEP' are required by
the Directive not to carry the mark.
Product Group 1
Gases
Group 2
Gases
Group 1
Liquids
Group 2
Liquids
Spirax SafeBlocTM
PN40
DN15 - DN25 SEP SEP SEP SEP
DN40 - DN50 2 1 SEP SEP
DN65 - DN100 212SEP
ANSI 300
DN15 - DN25 SEP SEP SEP SEP
DN40 - DN100 212SEP
i) The product has been specifically designed for use on steam, compressed air and water/
condensate which are in Group 2 of the above mentioned Pressure Equipment Directive.
ii) Check material suitability, pressure and temperature and their maximum and minimum values.
If the maximum operating limits of the product are lower than those of the system in which it
is being fitted, or if malfunction of the product could result in a dangerous overpressure or
overtemperature occurrence, ensure a safety device is included in the system to prevent such
over-limit situations.
iii) A number of products are supplied for the intention of the end user (or agent thereof) modifying
the flange configuration from that supplied. It is the responsibility of the organization carrying
out the modification to do so in accordance with the internationally recognized standards and
to ensure that the design rating and operation of the product are not compromised. Spirax
Sarco will not be held responsible for any unapproved modification or consequential liability
resulting in failure to observe these requirements.
iv) Determine the correct installation situation and direction of fluid flow.
v) Spirax Sarco products are not intended to withstand external stresses that may be induced
by any system to which they are fitted. It is the responsibility of the installer to consider these
stresses and take adequate precautions to minimise them.
vi) Remove protective covers from all connections and protective film from all name-plates, where
appropriate, before installation on steam or other high temperature applications.
1. Safety information

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1.2 Access
Ensure safe access and if necessary a safe working platform (suitably guarded) before attempting
to work on the product. Arrange suitable lifting gear if required.
1.3 Lighting
Ensure adequate lighting, particularly where detailed or intricate work is required.
1.4 Hazardous liquids or gases in the pipeline
Consider what is in the pipeline or what may have been in the pipeline at some previous time.
Consider: flammable materials, substances hazardous to health, extremes of temperature.
1.5 Hazardous environment around the product
Consider: explosion risk areas, lack of oxygen (e.g. tanks, pits), dangerous gases, extremes of
temperature, hot surfaces, fire hazard (e.g. during welding), excessive noise, moving machinery.
1.6 The system
Consider the effect on the complete system of the work proposed. Will any proposed action (e.g.
closing isolation valves, electrical isolation) put any other part of the system or any personnel
at risk?
Dangers might include isolation of vents or protective devices or the rendering ineffective of
controls or alarms. Ensure isolation valves are turned on and off in a gradual way to avoid system
shocks.
1.7 Pressure systems
Ensure that any pressure is isolated and safely vented to atmospheric pressure. Consider double
isolation (double block and bleed) and the locking or labelling of closed valves. Do not assume
that the system has depressurised even when the pressure gauge indicates zero.
1.8 Temperature
Allow time for temperature to normalise after isolation to avoid danger of burns.
1.9 Tools and consumables
Before starting work ensure that you have suitable tools and/or consumables available. Use only
genuine Spirax Sarco replacement parts.
1.10 Protective clothing
Consider whether you and/or others in the vicinity require any protective clothing to protect against
the hazards of, for example, chemicals, high/low temperature, radiation, noise, falling objects, and
dangers to eyes and face.
1.11 Permits to work
All work must be carried out or be supervised by a suitably competent person.
Installation and operating personnel should be trained in the correct use of the product according
to the Installation and Maintenance Instructions.
Where a formal 'permit to work' system is in force it must be complied with. Where there is no such
system, it is recommended that a responsible person should know what work is going on and, where
necessary, arrange to have an assistant whose primary responsibility is safety.
Post 'warning notices' if necessary.

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1.12 Handling
Manual handling of large and/or heavy products may present a risk of injury. Lifting, pushing,
pulling, carrying or supporting a load by bodily force can cause injury particularly to the back.
You are advised to assess the risks taking into account the task, the individual, the load and the
working environment and use the appropriate handling method depending on the circumstances
of the work being done.
Although the bonnet and handwheel will support the weight of the valve, it is recommended the
slings for lifting are positioned around the back of the pipe flanges on the main body.
1.13 Residual hazards
In normal use the external surface of the product may be very hot. If used at the maximum
permitted operating conditions the surface temperature of some products may reach temperatures
of 400 °C (752 °F).
Many products are not self-draining. Take due care when dismantling or removing the product from
an installation (refer to 'Maintenance instructions').
1.14 Freezing
Provision must be made to protect products which are not self-draining against frost damage in
environments where they may be exposed to temperatures below freezing point.
1.15 Disposal
Unless otherwise stated in the Installation and Maintenance Instructions, this product is recyclable
and no ecological hazard is anticipated with its disposal providing due care is taken.
1.16 Returning products
Customers and stockists are reminded that under EC Health, Safety and Environment Law,
when returning products to Spirax Sarco they must provide information on any hazards and the
precautions to be taken due to contamination residues or mechanical damage which may present a
health, safety or environmental risk. This information must be provided in writing including Health
and Safety data sheets relating to any substances identified as hazardous or potentially hazardous.

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2.1 Description
The Spirax SafeBlocTM is a double block and bleed bellows sealed
stop valve, which has been designed for use as an in-line double
isolation valve on steam, gas, liquid, condensate and water systems.
Available types
DBB3 steel body and bonnet with PN40 and ANSI 300 connections.
Bleed valve options
A bleed valve connection is provided to depressurise the downstream when the upstream valve is isolated.
This can be supplied with either a DN15 flanged, ½" screwed BSP or ½" socket weld connection and must
be stated at the time of order placement.
Standards
This product fully complies with the requirements of the Pressure Equipment Directive (PED) and carries
the mark when so required.
Certification
This product is available with certification to EN 10204 3.1. Note: All certification/inspection requirements
must be stated at the time of order placement.
Note: For additional information see Technical Information Sheet, TI-P165-01-EN-ISS1.
2.2 Sizes and pipe connections
DN15, DN20, DN25, DN40, DN50, DN65, DN80 and DN100 flanged EN 1092 PN40 and ANSI B 16.5 Class 300.
Face-to-face dimensions conform to EN 558-1 (PN) and EN 558-2 (ANSI class).
Fig. 1
2. General product information

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0 100 200 300 400 500 600 700
0 10 20 30 40 51
425
300
200
100
0
-29
700
500
300
100
0
-21
0 100 200 300 400 500
0 5 10 15 20 25 30 35 40
400
300
200
100
0
700
600
500
400
300
200
100
Pressure psi g
Temperature °F
ANSI 300
PN40
Temperature °C
Pressure bar g
Steam
saturation
curve
Temperature °C
Pressure bar g
Body design conditions PN40
PMA Maximum allowable pressure 40 bar g @ 0 °C (580 psi g @ 32 °F)
TMA Maximum allowable temperature 400 °C @ 24 bar g (752 °F @ 348 psi g)
Minimum allowable temperature -10 °C (14 °F)
PMO Maximum operating pressure for saturated steam service 30.4 bar g 441 (523 °F)
TMO Maximum operating temperature 400 °C @ 24 bar g (752 °F @ 348 psi g)
Minimum operating temperature
(Note: For lower operating temperatures consult Spirax Sarco)
-10 °C (14 °F)
Designed for a maximum cold hydraulic test pressure of: 60 bar g (870 psi g)
Body design conditions ANSI 300
PMA Maximum allowable pressure 51 bar g @ 37.7 °C (739 psi g @ 100 °F)
TMA Maximum allowable temperature 425 °C @ 28 bar g (797 °F @ 406 psi g)
Minimum allowable temperature -29 °C (-20 °F)
PMO Maximum operating pressure for saturated steam service 41.6 bar g (603 psi g)
TMO Maximum operating temperature 425 °C @ 28 bar g (797 °F @ 406 psi g)
Minimum operating temperature
(Note: For lower operating temperatures consult Spirax Sarco)
-29 °C (-20 °F)
Designed for a maximum cold hydraulic test pressure of: 77 bar g (1 117 psi g)
2.3 Pressure/temperature limits (ISO 6552)
Steam
saturation
curve
The product must not
be used in this region.
Temperature °F
Pressure psi g
The product must not
be used in this region.

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Note: Before actioning any installation observe the ‘Safety information’ in Section 1.
Referring to the Installation and Maintenance
Instructions, name-plate and Technical Information
Sheet, check that the product is suitable for the
intended installation:
3.1 Check materials, pressure and temperature
and their maximum values. If the maximum
operating limit of the product is lower than
that of the system in which it is being fitted,
ensure that a safety device is included in
the system to prevent overpressurisation.
3.2 Remove protective covers from all
connections, threaded blanking plug
from the bleed port (screwed and socket
weld version only) and the protective film
from all name-plates, where appropriate,
before installation on steam or other high
temperature applications. A suitable form
of isolation must be fitted to the bleed port
before commissioning of the line.
3.3 The valve can be installed in the horizontal
or vertical plane. When installed in the
horizontal plane the bleed port should
ideally be positioned at the bottom (see
Figure 2). Isolation of the bleed port should
be positioned as close to the valve as
possible to avoid back-up of condensate
in the isolated bleed line. The bleed port
connection must be piped to a safe visible
atmospheric place as close to the valve
as possible.
Please note there is no flow direction arrow
on the valve as it can be installed with flow
from right to left or left to right.
3.4 When installed on steam systems a suitable
steam trap should be fitted immediately
upstream of the isolation valve to drain
condensate. This will ensure drainage of
the pipe when the valve is closed, and
will prevent damage of the valve due to
waterhammer. The drain trap should be
either a ball float (FT) or thermodynamic
(TD) type. Correct condensate drainage of
all upstream pipework is also vital.
Fig. 2
Incorrect Installation
Correct Installation
Bleed point
3. Installation

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After installation or maintenance ensure that the system is fully functional. Carry out tests on any alarms
or protective devices.
5.1 The bellows sealed isolation valve plays an important role in the conservation of energy by eliminating
fugitive stem seal emissions.
5.2 The valve is operated manually by handwheels. Special care must be taken to ensure that the
movement is made in the correct direction.
To open the valves fully, it is recommended to turn the handwheels until the shafts are raised to the
maximum position, indicated by the (+) on the bonnet, then turn the handwheel clockwise 1/8 to ¼
turn to remove any backlash. This action prevents any force being applied to open a valve, which is
already fully open, resulting in damage to the stem, bellows unit or other components. Spirax Sarco
bellows sealed isolation valves are fitted with a position indicator, which can be found on the stem,
and should align with the (+) or (-) on the bonnet support pillars. (+ = fully open and - = fully closed).
5.3 If valve ‘keys’ are used care must be taken not to use excessive force when opening or closing the
valve.
5.4 A Valve Integrity Test must be undertaken prior to each double isolation of the system. Refer to
Figure 3 and the Table below for correct sequence of operation.
Flow from Left to Right (L-R) Flow Right to Left (R-L)
1. All valves closed 1. All valves closed.
2. Open bleed/drain valve C.2. Open bleed/drain valve C.
3. Open downstream valve B.3. Open downstream valve A.
4. Upstream valve Ashould remain closed. 4. Upstream valve Bshould remain closed.
5. After initial discharge of downstream
depressurisation from the bleed valve C,
no further steam/fluid should be observed
(integrity proved).
If fluid is observed check valve A is fully closed,
if fluid is still evident contact Spirax Sarco and
Do Not Use.
5. After initial discharge of downstream
depressurisation from the bleed valve C,
no further steam/fluid should be observed
(integrity proved).
If fluid is observed check valve B is fully closed,
if fluid is still evident contact Spirax Sarco and
Do Not Use.
It is advisable to place a copy of the above table in close proximity of the Spirax SafeBlocTM valve.
4. Commissioning
5. Operation

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Flow L - R
A
CB
Fig. 3
Flow R - L
A
CB
5.5 Before undertaking any maintenance of plant downstream of the valve both handwheels should be
isolated. Refer to Figure 3 and the Table below for the correct sequence of handwheel operation.
When handwheels Aand Bare closed and drain port Cis opened there will be an initial discharge
as the valve depressurises. If there should be any visible discharge after a short period, consult
Spirax Sarco Service Department.
Note: Handwheels should always be opened slowly to avoid system shocks.
Operation sequence
for the Spirax SafeBlocTM
Flow Left to Right (L-R)
Operation sequence
for the Spirax SafeBlocTM
Right to Left (R-L)
Isolation Opening Isolation Opening
Close AClose CClose BClose C
Open COpen BOpen COpen A
Close BOpen AClose AOpen B
For illustrative purposes refer to Steps 1 to 5 on pages 10 and 11.
Note: Name-plates are fitted to the valve to identify which handwheel operates which port. If the valve is
insulated, ensure the name-plates remain visible.

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Note: Before actioning any maintenance programme observe the ‘Safety information’ in Section 1.
Warning
The body/bonnet gaskets (11a and 11b) contain a thin stainless steel support ring which may cause
physical injury if not handled and disposed of carefully.
6.1 General information
Before undertaking any maintenance on the valve, ensure any pressure is isolated and safely vented to
atmospheric pressure. The valve should then be allowed to cool. When reassembling, ensure that all joint
faces are clean.
Ensure that the correct tools and necessary protective equipment are used at all times. When maintenance
is complete open isolation valves slowly and check for leaks.
Note: The bonnet bush and threads of the stem are packed with a high quality grease on assembly. It is
recommended to re-grease these items whenever maintenance is undertaken on the valve.
6.2 Sequence of operation for safe maintenance of plant
Please note: that all the drawings in Steps 1 to 5 are illustrated with the ow direction from left to right.
Key
= Valve open
= Valve closed
Step 1
=Normal operation
position
Step 2
=Full isolation position
6. Maintenance

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Step 3
=
Depressurise the
valve body and
establish isolation
integrity
Step 4
=Depressurise the
downstream system
Step 5
=It is now safe
to maintain the
downstream system
Return to Step 1
Please note: The Spirax SafeBlocTM is shown with the bellows sealed bleed valve option. Other bleed
arrangements are available on request.

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6.3 Handwheel
The handwheel (7) is not supplied as a spare part. However, to remove the handwheel unscrew the main
handwheel nut in a clockwise direction.
Place a suitable spanner (a detailed drawing is available from Spirax Sarco) across the flats of the bonnet
bush (2) and unscrew the handwheel in the normal way.
Note: the handwheel may be firmly secured on the bonnet bush (2). Refitting the handwheel is the opposite to
removal. Apply Loctite 638 to the threads of the handwheel boss and tighten to 50 N m (36 lbf ft). Remember
to tighten the handwheel nut to 40 N m (29 lbf ft) in an anticlockwise direction.
6.4 How to fit the body/bonnet gaskets
This can be carried out whilst the valve is connected in the pipeline:
-Remove the valve bonnet (2) from the body (1) by unscrewing the bonnet studs/nuts (9 and 10). The
body gasket (11b) is now visible and can quickly be replaced. Ensure the gasket face in the body (1) is
clean before fitting a replacement.
-To replace the second gasket (11a) which is situated between the bonnet (2) and the stainless steel
bellows support collar, firstly remove the clip-on position indicator and remove the locking screw. Rotate
the handwheel (7) in a clockwise direction. This pushes the main stem (6) downwards and creates a
gap between the bellows support collar and the bonnet (2). If the support collar remains attached to the
bonnet (2), gently prise the collar away from the bonnet being careful not to damage the collar. Do not
allow the bellows to stretch as this can reduce the bellows life.
-By continually rotating the handwheel (7) in a clockwise direction, the stem (6) can be unscrewed from
the bonnet bush. When the stem (6) is disconnected from the bonnet bush, unscrew the gland nut and
remove both this and the gland washer. Keep these parts safe as they are not supplied as spares. The
stem/bellows assembly (6 and 5) can now be withdrawn out of the bonnet (2). The second bellows
collar gasket (11a) can now be replaced - ensuring both the bellows support collar surface and bonnet
surface are clean and the gasket is accurately located. Before the stem / bellows assembly (6 and 5) is
reassembled into the bonnet (2), the stem packing ring (8) should be replaced (see Section 6.5).
6.5 How to fit the stem packing
By following through Section 6.3 it is now possible to replace the stem packing ring (8):
-Two stem packing rings are provided in the spares kit but only one is required.
-Ensure all of the old stem packing material is removed from the bonnet cavity and all locating surfaces
are clean.
-Valve assembly is the opposite to removal - remembering to fit a bellows collar gasket (11a) between
the bellows support collar and the valve bonnet (2).
-Slide the stem (6) through the bottom of the valve bonnet (2). Locate the new stem packing ring (8),
original gland washer and the gland nut over the stem. Do not allow the stem thread to damage the
inner surface of the gland packing ring (8). Screw the end of the stem into the bonnet bush at the top of
the valve bonnet. Ensure the solid stem pin (which is pressed into the stem (6) is aligned with the slot
inside the bonnet.
-Carefully slide the new packing ring (8) down the stem into the cavity and slide the original gland washer
on top of the packing ring (8).
-After the valve has been fully assembled remember to create a safe seal between the gland packing
ring (8) and the stem (6) by tightening down the gland nut to the recommended tightening torque (see
Table 1).

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Fig. 4
7
Bonnet
bush
10
Bellows
support
collar
1
9
11b
5
11a
Position
indicator
(clip-on) 6
8
Gland washer
Gland nut
Locking screw
Main handwheel nut
2

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6.6 How to fit the stem and bellows assembly
By following through Section 6.5 it is now possible to fit a new stem/bellows assembly (6, 5):
-Fitting this is opposite to removal - remembering to fit a bellows collar gasket (11a) between the bellows
support collar and valve bonnet (2).
-Ensure the bellows collar gasket (11a) is accurately located. Before fitting the new stem/bellows assembly
(6 and 5) into the bonnet (2).
-Apply a small amount of lubricating compound such as Gulf Sovereign LC grease to the end of the stem
pin (which is pressed into the stem).
-Ensure the stem pin is aligned with the slot inside the bonnet.
-Carefully slide the stem up through the bonnet.
-Before screwing the end of the stem into the bonnet bush remember to fit a new stem packing ring (8)
(see Section 6.5), the original gland washer (or gland follower) and gland nut (or gland flange) over the
stem (6). Do not allow the stem thread to damage the inner surface of the gland packing ring (8).
-Carefully slide the new packing ring (8) down the stem into the cavity and slide the original gland washer
(or gland follower if fitted) on top of the packing ring (8).
-After the valve has been fully assembled remember to create a safe seal between the gland packing
ring (8) and the stem (6) by tightening down the gland nut to the recommended tightening torque (see
Table 1).
6.7 How to fit the disc
By following through Section 6.5 it is now possible to replace the valve’s disc:
-To replace the disc (4) simply remove the old stem pin and replace the disc (4).
-Attach the new disc with the new stem pin (supplied). Where the disc (4) is attached using a retaining
nut and collet arrangement, simply prise the crimped skirt away from the retaining nut and unscrew.
Remove the collets remembering to save these and the retaining nut as they are not supplied as spares.
Fitting is the opposite to removal but ensure the collets and threads are lightly greased with lubricating
compound such as Molybdenum Sulphide.
-If a new disc is being fitted then crimp the collet retaining nut securely across two corners by deforming
the disc’s thin metal skirt. If the original disc is being fitted then re-crimp using a fresh part of the skirt.
Table 1 Recommended tightening torques
Item Size PN40 ANSI 300
mm N m (lbf ft) N m (lbf ft)
Bonnet bolts and
nuts (9 & 10)
DN15 - DN25 17 A /F 35 - 40 (26 - 29) 50 - 55 (36 - 40)
DN40 - DN65 19 A/F 55 - 60 (40 - 44) 85 - 90 (63 - 66)
DN80 - DN100 24 A/F 130 - 140 (95 - 103) 190 - 200 (140 - 147)
Gland nut
DN15 - DN80 22 A/F 5 - 10 ( 3.5 - 7) 5 - 10 ( 3.5 - 7)
DN100 32 A/F 15 - 20 (10.5 - 14 ) 15 - 20 (10.5 - 14)

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Fig. 5
7
Bonnet bush
10
Bellows
support
collar
1
9
11b
5
11a
Position
indicator
(clip-on) 6
8
Gland washer
Gland nut
Locking screw
Main handwheel nut
2
6.8 Final assembly:
-Ensure the bellows support collar and
gaskets (11a and 11b) are accurately
aligned with the bonnet (2) before final
assembly into the body (1).
-Tighten the bonnet bolts/nuts (9 and 10)
evenly to the recommended tightening
torque (See Table 1).

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Fig. 6
4
11b
5
11a
6
8
*10
*2
*9
*1
*Note:
Items 1, 2, 9 and 10 are not
available spares.
The spare parts available are shown in solid outline. Parts drawn in a grey line are not supplied as spares.
Available spares
Body/bonnet gasket and stem packing 8 (2 off), 11a, 11b
Stem and bellows assembly 6, 5
Disc 4
Note: The gasket contains sharp metal reinforcement, please
handle with care. For a complete overhaul of the valve 2 x
each spare is required.
7. Spare parts
How to order spares
Please note: for customer convenience
spares are supplied in kits to ensure
all the appropriate replacement parts
are supplied to carry out a specific
maintenance task e.g. when a stem
and bellows assembly is ordered,
parts (8, 11a and 11b) and (6 and 5)
will be included in the kit. Always order
spares by using the description given
above and state the size and type of
stop valve.
Example: 1 - Body/bonnet gasket
and stem packing for a DN15 Spirax
SafeBlocTM DBB3 double block and
bleed bellows sealed stop valve having
PN40 connections.