Spirax Sarco DCV8 User manual

IM-P601-02 CMGT Issue 7
1
1. Safety information
2. General product information
3. Installation
4. Commissioning
5. Operation
6. Maintenance
7. Spare parts
© Copyright 2018
Printed in France
6010050/7
DCV8
Disc Check Valve
Installation and Maintenance Instructions
IM-P601-02
CMGT Issue 7

IM-P601-02 CMGT Issue 7
2
start of text under grey section header box
start of text continuing from previous page
TRANSLATION RUN OVER

IM-P601-02 CMGT Issue 7
3
Safe operation of this product can only be guaranteed if it is 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 product is suitable for the intended use/application. The product listed
below complies with the requirements of the Pressure Equipment Directive (PED) and carries the
mark when so required. The product falls within the following Pressure Equipment Directive
category:
Product Group 1
Gases
Group 2
Gases
Group 1
Liquids
Group 2
Liquids
DCV8
DN15 - DN25 SEP SEP SEP SEP
DN32 2SEP SEP SEP
DN40 - DN50 2 1 SEP SEP
DN65 - DN80 212SEP
DN100 212SEP
i) The product has been specifically designed for use on steam, compressed air, 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

IM-P601-02 CMGT Issue 7
4
start of text under grey section header box
start of text continuing from previous page
TRANSLATION RUN OVER
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.

IM-P601-02 CMGT Issue 7
5
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.

IM-P601-02 CMGT Issue 7
6
start of text under grey section header box
start of text continuing from previous page
TRANSLATION RUN OVER
2.1 Description
DCV8 disc check valves are of a wafer pattern, designed to be sandwiched between DIN 2501 and EN 1092
flanges. Their function is to prevent reverse flow on a wide variety of fluids. The DCV8 is designed for use with
agressive fluids, vapours, acids and alkalines at high pressures and temperatures. The valves are provided
with an M8 threaded tapping for product earthing and conform to EN 558 part 1, series 49.
Standards
Designed and manufactured in accordance with ÄD Merkblatter. This product fully complies with the
requirements of the Pressure Equipment Directive (PED).
Standard shut-off
Standard valves conform to EN 12266-1 rate D.
Soft seated versions meet EN 12266-1 rate A, providing a differential pressure exists.
Certification
These products are available with certification to EN 10204 3.1. and the body is sourced from a TÜV
approved foundry.
Note: All certification/inspection requirements must be stated at the time of order placement.
Note: For additional product data see Technical Information Sheet TI-P147-01-EN-ISS1.
2.2 Sizes and pipe connections
DN15, DN20, DN25, DN32, DN40, DN50, DN65, DN80 and DN100.
Suitable for installation between the following flanges:
EN 1092/DIN 2501 PN10, PN16, PN25 and PN40.
Fig. 1 DCV8 disc check valve
2. General product information

IM-P601-02 CMGT Issue 7
7
2.3 Optional extras
Heavy duty springs (700 mbar opening pressure, up to DN65) for boiler feed applications
High temperature springs
Viton soft seats for oils and gas applications
EPDM soft seats for water applications
2.4 Materials
Part Material
Body 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 - Metal disc seat
'W' - Without spring - Metal disc seat
'H' - Heavy duty spring - Metal disc seat
'V' - Standard spring - Viton disc seat
'E' - Standard spring - EPDM disc seat
No identification indicates a standard spring with a metal disc.

IM-P601-02 CMGT Issue 7
8
start of text under grey section header box
start of text continuing from previous page
TRANSLATION RUN OVER
400
300
200
100
0
-196
700
600
500
400
300
200
100
0
-320
0 5 10
15
20 25 30 35 40
0 100 200 300 400 500 580
The product must not be used in this region.
A - B - DWithout standard or high temperature springs.
E - C - DStandard spring and heavy duty spring.
Body design conditions PN40
PMA Maximum allowable pressure 40 bar g @ 50 °C (580 psi g @ 122 °F)
TMA Maximum allowable temperature 400 °C @ 25.6 bar g (752 °F @ 371 psi g)
Minimum allowable temperature -196 °C (-320 °F)
PMO Maximum operating pressure (bar g) 40 bar g @ 50 °C (580 psi g @ 122 °F)
TMO Maximum operating
temperature
Standard spring 300 °C @ 27.6 bar g (572 °F @ 400 psi g)
Heavy duty spring 300 °C @ 27.6 bar g (572 °F @ 400 psi g)
High temperature spring 400 °C @ 25.6 bar g (752 °F @ 371 psi g)
Without spring 400 °C @ 25.6 bar g (752 °F @ 371 psi g)
Minimum operating temperature (standard disc) -196 °C (-320 °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: 60 bar g (870 psi g)
Note: Special testing to allow lower temperature operation can be provided at extra cost. Consult Spirax Sarco.
Temperature °C
Pressure bar g
Steam
saturation
curve
AB
E C
D
Pressure psi g
Temperature °F
2.6 Pressure/temperature limits
Note: Special testing to allow lower temperature operation can be provided at extra cost. Consult Spirax Sarco.

IM-P601-02 CMGT Issue 7
9
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 protection covers from all connections and protection film from all name-plates, where
appropriate, before installation on stream or other high temperature applications.
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 Figure 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 DCV8 can be fitted between EN 1092/DIN 2501 PN10, PN16, PN25 and PN40 flanges. They
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
Figure 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.
a
Fig. 2
c
d e
'b'
is the only acceptable orientation when a DCV is supplied without an internal spring
b
3. Installation

IM-P601-02 CMGT Issue 7
10
start of text under grey section header box
start of text continuing from previous page
TRANSLATION RUN OVER
Fig. 3
Open Closed
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.
4. Commissioning
5. Operation
Kvvalues
Size DN15 DN20 DN25 DN32 DN40 DN50 DN65 DN80 DN100 For conversion:
Cv(UK) = Kvx 0.963
Cv(US) = Kvx 1.156
Kv4.4 6.8 10.8 17 26 43 60 80 113
Opening pressures in mbar
Differential pressures with zero flow for standard and high temperature springs.
Flow direction
Direction DN15 DN20 DN25 DN32 DN40 DN50 DN65 DN80 DN100
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

IM-P601-02 CMGT Issue 7
11
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
There are no spare parts available for this product.
How to order a new product
Example: 1 off Spirax Sarco DN25, DCV8 disc check valve for fitting between DN25 PN40 flanges.
7. Spare parts

IM-P601-02 CMGT Issue 7
12
start of text under grey section header box
start of text continuing from previous page
TRANSLATION RUN OVER