Danfoss ORV 25-80 Instruction page 2

ENGLISH
Installation
Oils
Applicable to all common refrigeration oils.
Refrigerants
Applicable to all common refrigerants,
including R717 and non-corrosive gases/
liquids dependent onsealing material
compatibility.
The valve is only recommended for use in
closed circuits.
For further information please contact
Danfoss.
Temperature range
Minimum operating temperature:
≥ −10ºC (14ºF)
Continuous operation:
≤ +85°C (+185°F)
Short operating periods:
≤ +120°C (+248°F)
Pressure range
The valves are designed for a max.
working pressure of 40 bar g (580 psi g.)
Installation (Fig. 1)
The valve can be installed in any position
(fig. 1), however, oil spills can be avoided
when servicing, if the top is mounted
vertically upwards. The valve is designed
to withstand a high internal pressure.
However, the piping system should be
designed to reduce the risk of hydraulic
pressure caused by thermal expansion. It
must be ensured that the valve is protected
from pressure transients like accelerated
liquid in the system.
Recommended flow direction (Fig. 2)
To achieve correct flow direction and
function, the letter designations, A, B and C
on the valve housing must be followed as
shown in fig. 2. Refer to the technical leaflet
to find application example.
Welding (Fig. 3)
The top cover (2), gasket (6), spring (5), and
thermostatic element (7), must be removed
before welding (fig. 3), to prevent damage
to the thermostatic element sensor (7).
(This must be done if the valve has not
been ordered from the parts program.
When ordering from the parts program the
element is not mounted in the valve).
The teflon glide ring (3), in the housing (1),
should be removed if the temperature will
exceed 240°C (460° F). Only materials and
welding methods, compatible with the
valve housing material, should be used.
The valve should be cleaned internally to
remove weld debris on completion and
before the valve is reassembled.
2
Weld debris and dirt in the interior of the
housing and on the glide ring should be
avoided. Temperature during welding can
be limited to the required limit depending
on welding method and any cooling
applied to the valve body. (Cooling can be
ensured by, for example, wrapping a wet
cloth around the valve body). Damage to
the teflon glide ring should be avoided. The
valve housing must be free from stresses
(external loads) after installation.
Assembly (Fig. 5)
Remove weld debris and any dirt from
pipes and valve body before assembly.
Check that the Teflon glide ring is free
from damage prior to mounting the
thermostatic element (fig. 5).
Tightening (Fig. 4)
Tighten the top cover bolts using a torque
wrench, to the values indicated in the table
(fig. 4). Over tightening can cause damage
to the gasket.
Colours and identification
The ORV valves are painted with a red
oxide primer from the factory. Precise
identification of the valve is made via
the cast text on the valve body and top.
The external surface of the valve housing
must be treated with a suitable protective
coating after installation and assembly.
Maintenance
Servicing
The ORV will fail if the thermostatic
element is worn out.
It is recommended that the thermostatic
element is function tested if the
temperature control is not responding as
designed.
Test of thermostatic element (Fig. 6)
After dismounting of the thermostatic
element observe the element position. If
the temperature of the actuator is approx.
20°C (68°F), the element should look as
shown in fig. 6a.
Insert the active part of the element
into water. Make sure that the water
temperature is equal to "the set
temperature" added 6 º C / 43 º F (see fig. 6b).
The set temperature can be read from the
ingraving on the thermostatic element
(see fig. 6a).
Observe the element open into a position
as shown in fig. 6b. The difference between
fully open and fully closed should be
approx. 9.5 mm (0.375 in.). The element
must be replaced if this stroke cannot be
achieved.
DKRCI.PI.HP0.A3.77 / 520H4515
Glide ring
The surface of the glide ring must be
inspected to ensure that no damage
has occurred. Scratch marks and the like
can cause oil flow to bypass the element
making the temperature regulation less
accurate.
Assembly (Fig. 5)
Remove any dirt from the body before
the valve is assembled. Check that the
thermostatic element and top gasket are in
position.
Lubricate the glide ring for ease of fitting of
the thermostatic element. Excessive force
can damage the glide ring. Only apply
moderate force.
Reposition and secure top.
Tightening (Fig. 4)
Tighten the top bolts with a torque
wrench, to the values indicated in the table
(fig. 4). Over tightening can cause damage
to the gasket.
Use only original Danfoss parts, including
thermostatic elements, gaskets and
glide rings for replacement. Materials of
new parts are certified for the relevant
refrigerants and oils.
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.
© Danfoss A/S (AC-SMC/MWA), 12-2011