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ENGLISH
Installation
Refrigerants
Applicable to all common non-flammable
refrigerants, including R717 and non-
corrosive gases/liquids dependent on
sealing material compatability.
Flammable hydrocarbons are not recom-
mended. The valve is only recommended
for use in closed circuits. For further
information please contact Danfoss.
Temperature range
SVA-ST: –50/+150°C (–58/+302°F)
SVA-SS: –60/+150°C (–76/+302°F)
Pressure
SVA 10-65: The valves are designed for a max.
working pressure of 52 bar g (754 psi g).
SVA 80-200: The valves are designed for a
max. working pressure of 50 bar g (725 psi
g).
Installation
The valve must be installed with the spindle
vertically upwards or in horizontal position
(fig. 1). Valves should be opened by hand
without the use of tools or other devices
(fig. 3). The valve is designed to withstand
a high internal pressure. However, the
piping system should be designed to avoid
liquid traps and reduce the risk of hydraulic
pressure caused by thermal expansion. It
must be ensured that the valve is protected
from pressure transients like "liquid
hammer" in the system.
Attention!
SVA are shut off valves and must always
be either fully closed or fully open. Half
open positions are not allowed. In case
the valve is installed close to compressor
(economizer lines, oil lines etc.) or on other
lines subjected to high vibrations and
pulsations, it is necessary to install special
lock washers on the valve. Please refer to
the catalogue for additional information.
Recommended flow direction
To achieve optimum flow conditions, the
valve should be installed with the flow
towards the valve cone as indicated by the
arrow on the side of the valve body (fig. 2).
Flow in the opposite direction is also
acceptable (fig. 2), but slightly reduces the
k
- / C
value.
v
v
Welding
The bonnet should be removed before
welding (fig. 4) to prevent damage to the O-
rings in the packing gland and between the
valve body and bonnet, as well as the teflon
gasket in the valve seat. Only materials and
welding methods, compatible with the
valve housing material, must be welded
to the valve housing. The valve should be
cleaned internally to remove welding debris
on completion of welding and before the
valve is reassembled.
Avoid welding debris and dirt in the threads
of the housing and the bonnet.
© Danfoss A/S (AC-AKC / frz), 05 - 2009
Removing the bonnet can be omitted
provided that:
The temperature in the area between the
valve body and bonnet during welding
does not exceed +150°C/+302°F. This
temperature depends on the welding
method as well as on any cooling of the
valve body during the welding itself.
(Cooling can be ensured by, for example,
wrapping a wet cloth around the valve
body.) Make sure that no dirt, welding
debris etc. get into the valve during the
welding procedure.
Be careful not to damage the teflon cone
ring.
The valve housing must be free from
stresses (external loads) after installation.
Stop valves must not be mounted in
systems where the outlet side of the valve
is open to atmosphere. The outlet side of
the valve must always be connected to the
system or properly capped off, for example
with a welded-on end plate.
Assembly
Remove welding debris and any dirt from
pipes and valve body before assembly.
Check that the cone has been fully screwed
back towards the bonnet before it is
replaced in the valve body (fig. 5a).
Tightening
Thighten the bonnet with a torque wrench,
to the values indicated in the table (fig. 5b).
Colours and identification
The SVA valves are painted with a red oxide
primer in the factory. Precise identification
of the valve is made via the ID ring at
the top of the bonnet, as well as by the
stamping on the valve body. The external
surface of the valve housing must be
prevented against corrosion with a suitable
protective coating after installation and
assembly.
Protection of the ID ring when repainting
the valve is recommended.
SVA-SS valves are not painted and do not
require any protective coating.
Maintenance
Packing gland
When performing service and maintenance,
replace the complete packing gland only,
which is available as a spare part. As a
general rule, the packing gland must not
be removed if there is internal pressure
in the valve. However, if the following
precautionary measures are taken, the
packing gland can be removed with the
valve still under pressure:
Backseating (fig. 6)
To backseat the valve, turn the spindle
counter-clockwise until the valve is fully
open.
Pressure equalization (fig. 7)
In some cases, pressure forms behind the
DKRCI.PI.KD0.B4.52 / 520H1293
packing gland. Hence a handwheel or
similar should be fastened on top of the
spindle while the pressure is equalized.
The pressure can be equalized by slowly
screwing out the gland.
Removal of packing gland (fig. 8)
Handwheel and packing gland can now be
removed.
Dismantling the valve (fig. 9)
Do not remove the bonnet while the valve
is still under pressure.
- Check that the O-ring (pos. A) has not
been damaged.
- Check that the spindle is free of
scratches and impact marks.
- If the teflon cone ring has been
damaged, the whole cone assembly
must be replaced.
Replacement of the cone (fig. 9)
Unscrew the cone screw (pos. B) with an
Allen key.
SVA 10 ...................................................2.0 mm A/F
SVA 15-40 ............................................2.0 mm A/F
SVA 50-65 ............................................2.5 mm A/F
SVA 80-100 ............................................. 4 mm A/F
SVA 125-150 .......................................... 5 mm A/F
SVA 200 ................................................... 6 mm A/F
(An Allen key is included in the Danfoss
Industrial Refrigeration gasket set).
Remove the bolts (pos. C).
Number of bolts in pos. C:
SVA 10 ...............................................................6 pcs.
SVA 10-20 ..................................................... 10 pcs.
SVA 25-65 ..................................................... 14 pcs.
SVA 80-200 ................................................... 13 pcs.
The cone can then be removed. Place the
new cone on the spindle and replace the
bolts. Refit the cone screw in again using
Loctite No. 648. to ensure that the screw is
properly fastened.
Assembly
Remove any dirt from the body before the
valve is assembled. Check that the cone
has been screwed back towards the bonnet
before it is replaced in the valve body (fig. 5a).
Tightening
Tighten the bonnet with a torque wrench,
to the values indicated in the table (fig. 5b).
Tighten the packing gland with a torque
wrench, to the values indicated in the table
(fig. 10).
Use only original Danfoss parts, including
packing glands, O-rings and gaskets for
replacement. Materials of new parts are
certified for the relevant refrigerant.
In cases of doubt, please contact Danfoss.
Danfoss accepts no responsibility for
errors and omissions. Danfoss Industrial
Refrigeration reserves the right to make
changes to products and specifications
without prior notice.
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