Spirax Sarco DCV1 User manual

IM-S19-04-EN-ISS1 CMGT 1
1. Safety information
2. General product information
3. Installation
4. Commissioning
5. Operation
6. Maintenance
7. Spare parts
© Copyright 2018
Printed in France
1340050/7
DCV1, DCV3 and DCV3LT
Disc Check Valves
Installation and Maintenance Instructions
IM-S19-04-EN-ISS1
CMGT
PREVIOUS REFERENCE NO. IM-P134-07

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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.
1.1 Intended use
Referring to the Installation and Maintenance Instructions, name-plate and Technical Information
Sheet, check that the products are suitable for the intended use/application. The products
listed below comply with the requirements of the Pressure Equipment Directive (PED) and carry
the mark when so required. The products fall within the following Pressure Equipment
Directive category:
Product Group 1
Gases
Group 2
Gases
Group 1
Liquids
Group 2
Liquids
DCV1,
DCV3
and
DCV3LT
DN15 - DN25 SEP SEP SEP SEP
DN32 2SEP SEP SEP
DN40 - DN50 2 1 SEP SEP
DN65 - DN80 2 1 2 SEP
DN100 2 1 2 SEP
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) 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 minimise them.
v) Remove protection covers from all connections and protective film from all name-plates, where
appropriate, before installation on stream or other high temperature applications.
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. Safety information

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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 the danger of burns and consider
whether protective clothing (including safety glasses) is required.
Viton seat:
If the Viton seat has been subjected to a temperature approaching 315 °C (599 °F) or higher it may
have decomposed and formed hydrofluoric acid. Avoid skin contact and inhalation of any fumes
as the acid will cause deep skin burns and damage the
respiratory system.
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.
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 300 °C (572 °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
This product is recyclable. No ecological hazard is anticipated with the disposal of this product
providing due care is taken, except:
Viton seat:
-Waste parts can be landfilled, when in compliance with National and Local regulations.
-Parts can be incinerated, but a scrubber must be used to remove Hydrogen Fluoride, which is
evolved from the product and with compliance to National and Local regulations.
-Parts are insoluble in aquatic media.
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 General description
The DCV1, DCV3 and DCV3LT disc check valves are of the wafer pattern designed to be sandwiched between
flanges. They are suitable for use on a wide range of fluids for applications in process lines, hot water
systems, steam and condensate systems etc. Face-to-face dimensions conform to EN 558 part 1, series 49.
As standard the valves have a metal-to-metal seat. See Section 2.5 for other options which are available
on request.
Note: For additional information see Technical Information Sheets TI-P142-01-EN-ISS1 for the DCV1 or
TI-P143-01-EN-ISS1 for the DCV3 and DCV3LT.
2.2 Sizes and pipe connections
DN15, DN20, DN25, DN32, DN40, DN50, DN65, DN80 and DN100.
Suitable for installation between BS 10 Tables 'E' and 'H'.
EN 1092 PN6, PN10, PN16, PN25 and PN40; JIS 5, JIS 10, JIS 16 and JIS 20 flanges with the following
exceptions:
DN40, DN50, DN80 and DN100 - will not fit between JIS 5 flanges.
DN65 and DN80 - will not fit between BS 10 'E' flanges.
2.3 Optional extras
Heavy duty springs (700 mbar [10 psi] opening pressure up to DN65) for boiler feed applications.
Viton soft seats for oil, gas and steam applications.
EPDM soft seats for water applications.
Fig. 1
DCV1, DCV3 and DCV3LT
2. General product information

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2.4 Materials
Part Material
Body
DCV1 Bronze
DCV3 Austenitic stainless steel
DCV3LT Austenitic stainless steel
Disc Austenitic stainless steel
Spring retainer Austenitic stainless steel
Standard spring Austenitic stainless steel
Heavy duty spring Austenitic stainless steel
High temperature spring Nickel alloy
2.5 Seating options
The valves are stamped to identify the internals fitted:
'N' –High temperature spring –Standard metal disc
'W' –Without spring –Standard metal disc
'H' –Heavy duty spring –Standard metal disc
'V' –Standard spring –Viton soft faced disc
'E' –Standard spring –EPDM soft faced disc
'WV' –Without spring –Viton soft faced disc
'WE' –Without spring –EPDM soft faced disc
'HV' –Heavy duty spring –Viton soft faced disc
'HE' –Heavy duty spring –EPDM soft faced disc
'T' –Valves tested to EN 12266 rate D
No identification indicates a standard spring with a metal disc.

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2.6 Pressure/temperature limits - DCV1
0
260
200
150
100
50
0
-198
50 100 150200
50
0
40
0
30
0
20
0
10
0
0
04 81
21
6
Temperature °C
Pressure bar g
Pressure psi g
Temperature °F
Steam
saturation
curve
The product must not be used in this region.
Please note: The figures displayed are only relevant when a metal-to-metal seat is used. If Viton or EPDM
seats are used the product is restricted to the limits of the seat material chosen.
Body design conditions for saturated steam service PN16
PMA Maximum allowable pressure 16 bar g @ 120 °C (232 psi g @ 248 °F)
TMA Maximum allowable temperature 260 °C @ 7 bar g (500 °F @ 101 psi g)
Minimum allowable temperature -198 °C (-324 °F)
PMO Maximum operating pressure for saturated steam
service 13.2 bar g @ 196 °C (191 psi g @ 355 °F)
TMO Maximum operating temperature 260 °C @ 7 bar g (500 °F @ 101 psi g)
Minimum operating temperature
Note: For lower operating temperatures consult Spirax Sarco -198 °C (-324 °F)
Temperature limits
Viton seat -25 °C to +205 °C (-13 °F to 401 °F)
EPDM seat -40 °C to +120 °C (-40 °F to 248 °F)
Designed for a maximum cold hydraulic test pressure of 24 bar g (348 psi g)
Note: Special testing to allow lower temperature operation can be provided at extra cost. Consult Spirax Sarco.

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0 100 200 300 400 500
700
600
500
400
200
100
-14
-76
400
300
200
100
0
-10
-60
0 10 20 30 40
Pressure psi g
Temperature °F
2.7 Pressure/temperature limits - DCV3 and DCV3LT
The product must not be used in this region.
Use either a DCV3 with high temperature spring or DCV3/DCV3LT without spring for use in this area.
A-B-F DCV3 without spring and with high temperature spring.
A-B-D DCV3LT without spring.
E-C-F DCV3 with standard spring and heavy duty spring.
E-C-D DCV3LT with standard spring and heavy duty spring.
Please note: The figures displayed are only relevant when a metal-to-metal seat is used. If Viton or EPDM
seats are used the product is restricted to the limits of the seat material chosen.
Pressure bar g
Temperature °C
A
E
B
C
D
Steam
saturation
curve
F
Only the DCV3LT can be used down to -60 °C

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Body design conditions PN40
PMA Maximum allowable pressure 40 bar g @ 50 °C (580 psi g @ 122 °F)
TMA Maximum allowable temperature 400 °C @ 31.2 bar g (752 °F @ 452 psi g)
Minimum allowable temperature
DCV3 -10 °C (14 °F)
DCV3LT -60 °C
PMO Maximum operating pressure (metal-to-metal seat) 40 bar g @ 50 °C (580 psi g @ 122 °F)
TMO
Maximum
operating
temperature
Standard spring 300 °C @ 33.3 bar g (572 °F @ 483 psi g)
Heavy duty spring 300 °C @ 33.3 bar g (572 °F @ 483 psi g)
High temperature
spring DCV3 only 400 °C @ 31.2 bar g (752 °F @ 452 psi g)
Without spring 400 °C @ 31.2 bar g (752 °F @ 452 psi g)
Minimum operating temperature
Note: For lower operating temperatures
consult Spirax Sarco
DCV3 -10 °C (14 °F)
DCV3LT -60 °C
Temperature limits
Viton seat -25 °C to +205 °C (-13 °F to 401 °F)
EPDM seat -40 °C to +120 °C (-40 °F to 248 °F)
Designed for a maximum cold hydraulic test pressure of 60 bar g (870 psi g)

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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 Determine the correct installation situation and the direction of fluid flow.
3.3 Remove protective covers from all connections.
3.4 Valves must only be installed where 'weld neck' flanges are used. Other flange types may restrict
operation.
3.5 Disc check valves simply fit between two pipe flanges (see Fig. 2). Standard gaskets are used either
side of the valve together with longer bolts or studs. Note: flanges, bolts (or studs), nuts and joint
gaskets to be provided by the installer. Normal sensible flange bolting practice should be followed
eg. torque tightening the bolts in opposite sequence.
3.6 The DCV1, DCV3 and DCV3LT can be installed in any plane with the exception of DCV's supplied
without an internal spring. These must be fitted in a vertical flow line with the flow from bottom-to-
top i.e. upward flow (see Fig. 2b). Disc check valves must be fitted in accordance with the direction
of the flow arrow on the body, indicating correct fluid flow direction.
Note: Disc check valves are not suitable for use where heavily pulsating flow exists, such as close to a
compressor.
Fig. 2
a b c
de
'b' is the only acceptable
orientation when a DCV is supplied
without an internal spring
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.
Disc check valves are opened by the pressure of the
fluid and closed by the spring as soon as the flow
ceases and before the reverse flow occurs.
Fig. 3
4. Commissioning
5. Operation
Open Closed
Kvvalues
DN 15 20 25 32 40 50 65 80 100
Kv4.4 6.8 10.8 17 26 43 60 80 113
For conversion:
Cv(UK) = Kvx 0.963
Cv(US) = Kvx 1.156
Opening pressures in mbar
Differential pressures with zero flow for standard and high temperature springs.
Flow direction
DN 15 20 25 32 40 50 65 80 100
25 25 25 27 28 29 30 31 33
22.5 22.5 22.5 23.5 24.5 24.5 25 25.5 26.5
20 20 20 20 20 20 20 20 20
Where lowest opening pressures are required, valves without springs can be installed in vertical pipes
with bottom-to-top flow.
Without spring
2.5 2.5 2.5 3.5 44.5 55.5 6.5
Heavy duty springs approximately 700 mbar

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There are no spare parts available for this product.
How to order a new product
Example: 1 off Spirax Sarco DN25, DCV3 Austenitic stainless steel disc check valve for fitting between
DN25, PN40 flanges.
Note: Before actioning any maintenance programme observe the 'Safety information' in Section 1.
This product is non-maintainable.
Note: Great care must be taken if a DCV with a heavy duty spring is taken apart since the strength of the
spring can cause the retainer to spring out of the body.
6. Maintenance
7. Spare parts