Spirax Sarco DLV7 User manual

IM-P204-03 CH Issue 8
1
1. Safety information
2. General product
information
3. Installation
4. Maintenance -
DN15 to DN32 valves
5. Maintenance -
DN40 to DN100 valves
6. Spare parts
© Copyright 2016
Printed in GB
IM-P204-03
CH Issue 8
2046050/8
DLV7 SG Iron
Pressure Reducing Valve
Installation and Maintenance Instructions

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Safe operation of the unit can only be guaranteed if it is properly installed,
commissioned and maintained by a qualified person (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
Care should be exercised when handling gaskets since the stainless steel reinforcing
strip can easily inflict cuts.
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 products listed below comply with the requirements of the European Pressure
Equipment Directive 2014/68/EU and carry the mark when so required.
The products fall within the following Pressure Equipment Directive categories:
Product Group 1
gases
Group 2
gases
Group 1
liquids
Group 2
liquids
DLV7
DN15 – DN40 PN16 and PN25 -SEP - -
DN50 PN16 -SEP - -
DN50 PN25 - 1 - -
DN65 – DN100 PN16 and PN25 - 1 - -
WS4 -SEP - -
WS4-3 - 1 - -
i) The products have been specifically designed for use on steam which is in
Group 2 of the above mentioned Pressure Equipment Directive. The product's
use on other fluids may be possible but, if this is contemplated, Spirax Sarco
should be contacted to confirm the suitability of the product for the application
being considered.
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 over temperature occurrence, ensure
a safety device is included in the system to prevent such over-limit situations.
iii) Determine the correct installation situation and direction of fluid flow.
iv) 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 minimize
them.
v) Remove protection 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 substances 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 the danger of burns
and consider whether protective clothing (including safety glasses) is required.
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.

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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.
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.
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 250 °C (482°F). Many products are not self-draining. Take
due care when dismantling or removing the product from an installation (refer to
'Maintenance instructions').
Self-acting valves may operate unexpectedly during normal service. The risk of
personal injury should be assessed for each installation. Where appropriate, suitable
guarding should be fitted.
1.14 Freezing
Provision must be made to protect products which are not selfdraining 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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Note: The DLV is not suitable for liquid applications
2.1 Description
The DLV pressure reducing valve is a direct acting self-powered valve of robust
construction, designed to operate under arduous conditions - Ideal for steam applications.
The valve is controlled by downstream pressure acting directly on the diaphragm to oppose
a 'set' spring force. Under stable conditions diaphragm force and spring force are in a state
of balance, but an increase or decrease in demand raises or lowers the downstream pressure
which in turn acts against the spring to close or open the valve to adjust the flowrate and
maintain a constant downstream pressure.
The DLV is 'routine' maintenance free. It is a single seat, bellows sealed valve available in
sizes ranging from DN15 to DN100 flanged EN 1092 PN16 and PN25 with downstream
pressure ranges of between 0.2 bar to 13 bar.
Standards and approvals
This product fully complies with the requirements of the European Pressure Equipment
Directive 2014/68/EU and carries the mark when so required.
Certification
This product is available with a manufacturer's Typical Test Report. Note: All certification /
inspection requirements must be stated at the time of order placement.
Note: For further product data see Technical Information sheet TI-P204-04.
2. General product information

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The product must not be used in this region.
A-B-C Flanged EN 1092 PN16.
A-D-E Flanged EN 1092 PN25.
Body design conditions PN25 PN16
Maximum design pressure 25 bar g @ 100 °C 16 bar g @ 100 °C
Maximum design temperature 250 °C @ 21.8 bar g 250 °C @ 13.9 bar g
Minimum design temperature 0°C 0°C
Maximum operating temperature 250 °C @ 21.8 bar g 250 °C @ 13.9 bar g
Minimum operating temperature 0°C 0°C
Note: For lower operating temperatures consult Spirax Sarco
Maximum differential pressure 16 bar g
Designed for a maximum cold hydraulic test pressure of: 24 bar g
Note: With internals tted, test pressure must not exceed 16 bar g
Pressure bar g
Temperature °C
Steam
saturation
curve
A B D
C E
2.2 Pressure / temperature limits

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Fig. 1 DN15 to DN32 Fig. 2 DN40 to DN100
2.3 Available types:
The DLV7 is available with the following pressure ranges:
Valve +Actuator and Size Pressure range
(bar)
Actuator
PN rating
DLV71 DN100 0.5 - 1.5 2.5
DLV72
DN15 to DN50 0.2 - 1.8
2.5
DN65 to DN80 0.4 - 1.8
DLV73 DN100 1.0 - 4.0 6.0
DLV74
DN15 to DN80 1.0 - 5.5 16.0
DN100 3.5 - 13 16.0
DLV75 DN15 to DN80 4.0 - 13 25.0

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2.4 Water seal pot - WS4 / WS4-3 (optional extra)
Fig. 3 Water seal pot
Water fill connection
Actuator pressure signal
Technical details
Available types
WS4 The WS4 is for normal applications up to a volume of 1 litre.
WS4-3 The WS4-3 has a larger 3 litre volume and is recommended
where there is rapid fluctuation of pressure or load.
Connection sizes
Inlet
" BSP male
Screwed WS4 " NPT male BS 21
Screwed WS4-3 ½" BSP male BS 21
½" NPT male
DN10
Butt weld WS4 DN15
Outlet Screwed " BSP female BS 21 with 8 mm compression fittings
Materials
Housing Carbon steel
Downstream pressure pipe

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2.5 Pressure / temperature limits - WS4 / WS4-3
The product must not be used in this region.
Body design conditions PN25
Maximum design pressure 25 bar g @ 120 °C
Maximum design temperature 225 °C @ 21 bar g
Minimum design temperature 0°C
Maximum operating pressure for saturated steam 21 bar g
Maximum operating temperature 225 °C @ 21 bar g
Minimum operating temperature 0°C
Note: For lower operating temperatures consult Spirax Sarco
Maximum differential pressure 25 bar g
Designed for a maximum cold hydraulic test pressure of 40 bar g
Note: With internals fitted, test pressure must not exceed 25 bar g
Pressure bar g
Temperature °C
Steam
saturation
curve

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Note: Before actioning any installation observe the 'Safety information' in Section 1.
3.1 General information
The valve should be installed in a horizontal pipeline.
For operating temperatures below 125 °C the valve may be installed either vertically upwards
or vertically downwards (see Figure 4).
For operating on steam or temperatures above 125 °C the valve must be installed vertically
downwards with the spring / actuator below the pipework with a water seal pot fitted on the
downstream control signal line to the actuator, a typical installation is shown in Figure 5.
Care should be taken to install the valve correctly as indicated by the direction of flow arrow
on the valve body.
3. Installation
Fig. 4 Typical installation for
downstream temperatures below 125 °C
the valve can alternatively be mounted
vertically upwards.
* 1 m or 15
pipe diameters
minimum
* *
Steam
Steam
Condensate
Fig. 5 Typical installation for downstream
temperatures above 125 °C
* *
WS4 water seal pot
Steam
Steam
Condensate
3.2 Pressure control pipe
The valve actuator signal connection must be piped directly to the downstream side. To
provide a good control signal the downstream sensing point should be positioned a minimum
of 1 metre or 15 pipe diameters away from the valve or change in pipework direction on either
side. It is recommended that the actuator signal pipe should be 8 mm diameter copper or
stainless steel of 1 m minimum length.
3.3 Preventing dirt
Before installing the valve the system pipework should be flushed out to remove any residual
dirt or scale that may be present. The valve should be protected by a pipeline strainer of the
same size as the upstream pipework. For steam applications the strainer should be installed
on its side to prevent the accumulation of water.

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3.4 Removal of condensate
For steam installations a separator should be
installed on the upstream side of the valve
fitted with a suitable steam trap.
3.5 Pressure gauges
To assist in commissioning the valve and
monitoring operating conditions it is essential
to fit pressure gauges on both upstream and
downstream sides of the valve.
3.6 Safety valve
It is recommended that a suitable safety valve
is installed on the downstream side of the
valve to protect downstream equipment from
excessive pressure. The valve should be set
to lift at a pressure below the safe working
pressure of the downstream equipment and
sized to pass the full capacity of the DLV
should it fail in the fully open position. The
safety valve outlet pipework should discharge
to a safe place.
3.7 Isolating valves
It is recommended that manually operated
isolating valves are installed upstream and
downstream of the pressure reducing valve
station to provide means of isolation for
cleaning and maintenance.
3.8 Water seal pot
If fitted, the water seal pot must be charged with water prior to the valve being put into service.
Remove the water seal pot filling plug and fully charge the vessel with soft water. Replace
the filling plug.
For applications where there are rapid fluctuations in load or pressure the larger volume
WS4-3 is recommended.
To commission the valve, slowly open the upstream manual isolating valve to avoid
waterhammer. The pressure reducing valve is now ready for operation.
3.9 Setting the desired downstream pressure
The valve is supplied 'unset' with the spring adjuster at its lowest adjustment position. The
downstream pressure may be set against either a dead end condition or flowing condition,
depending on the requirements of the application, taking into account the effect of proportional
offset.
The desired downstream pressure is obtained by rotating the adjustment nut whilst monitoring
the downstream pressure gauge.
Adjustment can be made using a standard open ended spanner size 30 mm A/F for all valves.
Compressing the control spring increases downstream set pressure and conversely relaxing
the spring tension reduces the downstream set pressure (see Figure 6).
Note: Prior to any re-adjusting of the set pressure, ensure the valve stem is coated with a
suitable high temperature lubricant.
Flow
direction
Increase
set
pressure
Reduce
set
pressure
Adjustment
nut
Fig. 6

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4. Maintenance (DN15 to DN32)
Note: Before actioning any maintenance programme observe the 'Safety information'
in Section 1.
Warning
This product should not be dismantled without first releasing the compression on
the control spring.
General information
The valve is maintenance free, but it is recommended that the valve is dismantled every
12 to 18 months for routine inspection of the component parts. Items showing signs of
wear should be replaced.
Details of available spares are given in Section 6.
Prior to routine inspection or fitting spare components, firstly ensure that the DLV is isolated
and that the upstream and downstream pressures are reduced to zero. This is achieved by
rotating the adjustment nut to reduce the spring compression to zero.
The downstream pressure signal pipe should be disconnected from the actuator.
Tools list
Part description Applicable
range Tool size Tool required
Torque
N m
Actuator location nut Type 2, 4
and 5 17 A / F Spanner 15 - 18
Actuator stud
coupling
Type 2, 4
and 5 12 A / F and 14 A / F Spanner 7 - 9
Pillar nut DN15 - DN32 19 A / F Spanner 25 - 32
Adjuster lock-nut DN15 - DN32 22 A / F Spanner -
Adjuster nut DN15 - DN32 30 A / F Spanner -
Bellows clamp
DN15 - DN20 15 A / F Spanner -
DN25 - DN32 22 A / F Spanner -
Clamp nut
DN15 - DN20 30 A / F Spanner 60 - 65
DN25 - DN32 36 A / F Spanner 60 - 65
Bonnet capscrew M10 DN15 - DN32 8 A / F Hexagon
key 28 - 32
Head flat DN15 - DN20 19 A / F Spanner 15 ±1
Adaptor DN25 - DN32 24 A / F Spanner 20 ±2

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4.1 Removal of the valve bonnet
Using a spanner, hold the adjustment
nut, then loosen the lock-nut.
Loosen the adjustment nut.
1 2
3 4
Remove the lock-nut.
Pillar
Loosen and remove the pillar securing
nuts and washers using a 19 mm A / F
spanner. Then proceed to remove the
pillar.
Lock-nut

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Remove the adjustment spring and the
lower spring plate.
5 6
7 8
Remove the upper spring plate.
Remove the adjustment nut and thrust
washers.
Loosen and remove the bonnet cap
screws using a hexagon key.
4.1 Removal of the valve bonnet (continued)
Adjustment
nut
Upper
spring
plate
Lower
spring
plate

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Lift the bonnet assembly away from
the valve body.
4.1 Removal of the valve bonnet (continued)

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B
C
4.2 Replacement of the head set
Although the seat is non-replaceable
the gasket surface area will need
cleaning.
Screw two M14 nuts on to the valve
stem and tighten together.
Note: hold nut A. Only tighten nut Bto
ensure no damage to the bellows.
Seat
Gasket
surface
1 2
Hold the nut Busing a 22 mm A / F spanner and loosen the head adaptor nut Cwith a
24 mm A / F spanner.
Caution: to prevent any damage care must be taken not to twist the bellows.
3
A
B

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B
C
Remove the head set and guide plate.
Note: Remove and clean the guide plate and the gasket surfaces and fit new gaskets
throughout.
E
4 5
Replace the guide plate and screw the new head set onto the stem (hand tight). Then
proceed to tighten by holding the nut Busing a 22 mm A / F spanner and tighten the
head adaptor nut Cwith a 24 mm A / F spanner to a torque of 15 ±1 N m for the DN15
- DN20 and 20 ±2 N m for the DN25 - DN100. Caution: to prevent any damage care
must be taken not to twist the bellows. To prevent over-extension (stretching) of the
bellows locate the guide plate on the head set before tightening the plug to the stem.
When replacement of the head set is complete, remove nuts Aand B.
6
Gasket surfacesGuide plate

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Gasket surfaces
4.3 Replacement of the bellows assembly
4
Remove the bellows guide plate and
clean the gasket surfaces.
2
Remove the head set.
Hold the lock-nut Busing a 22 mm A / F
spanner and loosen the head adaptor
nut Cwith a 24 mm A / F spanner.
Caution: to prevent any damage care
must be taken not to twist the bellows.
C
A
B
Screw two M14 nuts on to the valve stem
and tighten together.
Note: only tighten nut Bto ensure no
damage to the bellows.
1
B
3

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5
Using a 24 mm A / F spanner hold the two
flat edges on the bellows and then unscrew
the clamp nut using a 30 mm A / F spanner
for the DN15 and DN20 sizes and a 36 mm
A / F spanner for the DN25 and DN32 sizes.
6
7
Supporting the bellows assembly
proceed to remove the bellows from the
bonnet.
Gasket
face
Remove and clean gasket material
from the upper end of the bellows and
inside of the bonnet. Then remove and
clean gasket material from the bellows
housing.
Remove the bonnet gasket and clean.
8

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Arrangement of
the gaskets for
reassembly of the
bellows.
4.3 Replacement of the bellows assembly (continued)
9
Bellows gasket
Ensure that the internal gasket face
is clean before placing a new upper
bellows gasket over the spindle and
carefully fitting the bellows into the
bonnet.
Carefully place a new inner bonnet
gasket followed by the spindle guide
plate.
Replace the nut and hand tighten.
Using a 24 mm A / F spanner hold the two
flat edges on the bellows and then tighten
the clamp nut to a torque of 60 - 65 Nm
by using a 30 mm A / F spanner for the
DN15 and DN20 sizes and a 36 mm A / F
spanner for the DN25 and DN32 sizes.
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