Thermostatic operated water valves are used
for proportional regulation of ow quantity,
depending on the setting and the sensor
temperature.
The Danfoss range of thermostatic operated
water valves includes a series of products for
both refrigeration and heating regulation. The
valves are self-acting, i.e. they operate without
the supply of auxiliary energy such as electricity
or compressed air.
The required temperature is maintained
constant without unnecessary use of:
• cooling water in cooling systems
• hot water or steam in heating systems
The operating economy and eciency are
maximized.
AVTA SS for aggressive media:
A valve body in stainless steel means that the
valve can be used for aggressive media in such
applications as the marine sector and the
chemical industry.
AI193586424671en-000901
Data Sheet
Thermostatic operated water valve
Type AVTA
Opens on rising sensor temperature
Features
• Insensitive to dirt
• Insensitive to water pressure
• Needs no power supply – self acting
• Opens on rising sensor temperature
• Dierential pressure: 0 – 10 bar
• Maximum working pressure (PS): 16 bar
• Maximum test pressure: 25 bar
• Maximum pressure on sensor: 25 bar
• Stainless steel version available
• The valves are pressure-relieved, i.e. degree of opening is not aected by dierential pressure Δp (pressure drop).
• The regulation range is dened for the point at which the valve begins to open.
• Cooling media temperature range: -25 – 130 °C
• Ethylene glycol as a cooling media up to 40%
Thermostatic operated water valve, Type AVTA
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1.
2.
3.
4.
5.
6.
1
2
3
Danfoss
3N1101.13
Danfoss
3N1102.12
Danfoss
3N1103.13
1
2
3
Setting section with knob, reference spring and setting scale.
Valve body with orice, closing cone and sealing elements.
Hermetically sealed thermostatic element with sensor, bellows and
charge.
Functions
How it works?
When the three elements have been assembled together, the valve installed and the sensor located at the point
where the temperature is to be regulated, the function sequence is as follows:
The pressure changes in the sensor as a result of a change in temperature - builds up in the sensor.
This pressure is transferred to the valve via capillary tube and bellows and acts as an opening or closing force.
The knob on the setting section and the spring exert a force that acts counter to the bellows.
When balance is created between the two opposing forces, the valve spindle remains in its position.
If the sensor temperature changes – or if the settings are changed – the point of balance becomes displaced and
the valve spindle moves until balance is re-established, or the valve is fully open or closed.
The ow quantity change is approximately proportional to sensor temperature change.
Figure 1 show an AVTA cooling water valve, but the function principle applies to all types of thermostatic valves.
Figure 1: Thermostat operated water valves consist of three main elements
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Thermostatic operated water valve, Type AVTA
1
2
3
4
5
Oil tank
Hydraulic machinery
Heat exchangers
Cooling water supply
ATVA thermostatic valve
Applications
Figure 2: AVTA
AVTA thermo. operated water valves are widely used for temperature regulation in many dierent machines and
installations where cooling is required. AVTA cooling water valves always open to admit ow on rising sensor
temperature.
The valve can be installed in either the cooling water ow line or the return line.
The standard version of the ATVA thermo. operated water valve can be used with fresh water or neutral brine.
Typical application areas:
• Injection moulding machines
• Compressors
• Vacuum pumps
• Dry cleaning machines
• Distillation plants
• Printing machines
• Hydraulic systems
• Roller mills
• Biomass boilers
• Industrial lasers
• Steam sterilizers
• Medical equipment
• Food processing
Figure 3: Applications
Thermostatic operated water valve, Type AVTA
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Product specication
Materials
Figure 4: Materials for AVTA and AVTA SS
Danfoss
3N158
6
7
2
1
4
3
5
2
Table 1: Materials
No.
Description
Material AVTA
Material AVTA SS
1
Spindle
Brass
Stainless steel
2
Diaphragms
3
Valve body and other metal parts
Forged brass
Stainless steel
4
Valve seat
5
Valve cone
6
Sensor
7
Capillary tube gland
Types of charges
Table 2: ATVA thermo. operated water valves with dierent types of charge.
Universal charge
Mass charge
Adsorption charge
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Thermostatic operated water valve, Type AVTA
Installation
AVTA with mounting bracket
Figure 5: AVTA
The valves can be installed in any position. An arrow on the valve body indicates the direction of ow.
AVTA valves are marked so that the letters RA are the right way up when the valve is held as shown. The installation
of an FV lter ahead of the valve is recommended.
Capillary tube
Install the capillary tube without sharp bends (no ”kinks”). Make sure that there is no strain on the capillary tube at
the ends. Relief is important where vibration might occur.
NOTE:
When an AVTA valve is used, the sensor must be able to react to variations in cooling water temperature on system
start. Therefore a bypass line with a shut-o valve might be necessary to ensure ow at the sensor during start-up. If
a mounting bracket is used – see Accessories and Spare parts – it must always be positioned between the valve
body and the setting section (see illustration).
Sizing
When sizing and selecting thermo. operated water valves, it is most important to ensure that the valve is able to
give the necessary quantity of cooling water at any time, irrespective of the load. Therefore, to select a suitable size
of valve it is necessary to know the precise amount of cooling required. On the other hand, to avoid the risk of
unstable regulation (hunting), the valve should not be oversized.
The type of charge must be selected on the basis of the temperature to be maintained, and on an assessment of the
characteristics of each type, as described in the foregoing.
In general the aim should be to select the smallest valve capable of giving the required ow.
It is also recommended that the temperature range be chosen so that the required sensor temperature lies in the
middle of the regulation range.
To help ne-setting the valve, a thermometer should be installed near the sensor.
Valve size
The following data are used when selecting the valve size:
• Required cooling water ow, Q [m
3
/h]
• Temperature rise in cooling water, Δt [°C]
• Dierential pressure across valve, Δp [bar]
Thermostatic operated water valve, Type AVTA
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With fully open valve, the dierential pressure should be around 50% of the total pressure drop across the cooling
system.
The following chart are intended to make valve sizing easier.
Figure 7: Heating or cooling with water
Figure 8: Relation between water quantity and pressure drop across valve
Figure 9: Nomogram showing the valve k
v
range
Figure 10: Valve ow quantity in fully open position, as a function of pressure drop Δp.
Example:
A cooling water valve must be selected for the temperature regulation of a vacuum pump.
Since direct regulation of the oil temperature is required, an AVTA valve is suitable. The sensor position is horizontal
– and small dimensions are desired.
Given data:
• Necessary cooling at full load 10 kW
• Oil temperature to be maintained constant at 45 °C
• Cooling water p
1
= 3 bar
• Outlet p
3
= 0 bar
• p
2
=
p
2
+ p
3
2
(guess)
• Cooling water temperature t
1
= 20 °C
• Outlet temperature t
2
= 30 °C 1
The graphs in
Figure 7: Heating or cooling with water can be used to nd the necessary cooling water quantity at Δt
= 10 °C (30 – 20 °C) to 0.85 m
3
/h.
The graphs in Figure 8: Relation between water quantity and pressure drop across valve show the necessary k
v
value
for 0.85 m
3
/h with Δp = p
1
- p
2
= 3 - 1.5 = 1.5 bar for 0.7 m
3
/h.
The columns in Figure 9: Nomogram showing the valve k
v
range show that all four AVTA valves can be used, but in
practice an AVTA 10 or 15 shall be selected, so the necessary water ow is in the middle of the regulating range.
The above considerations apply to both AVTA and FJVA types.
Operating conditions and other product requirements in this example mean that a valve with adsorption charge is
the correct choice. The temperature range 10 – 80 °C is in order.
Table 4: AVTA with adsorption charge shows AVTA 10, code no. 003N1144, or AVTA 15, code no. 003N0107. Both full
the requirements named.
In many applications, installation conditions make the use of sensor pockets advisable.
Accessories gives the code nos. for sensor pockets for ø9.5 mm sensors in brass and stainless steel: 017-436766 and
003N0196, respectively.
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Thermostatic operated water valve, Type AVTA
Figure 7: Heating or cooling with water
Q [m
3
/h]
Danfoss
3N492
Figure 6: Connection
Example:
Necessary cooling output 10 kW with ∆t = 10 °C
Required ow 0.85 m
3
/h
Thermostatic operated water valve, Type AVTA
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Figure 8: Relation between water quantity and pressure drop across valve
Example:
Flow 0.85 m
3
/h with a pressure drop of 1.5 bar.
The k
v
value becomes 0.7 m
3
/h.
Figure 9: Nomogram showing the valve k
v
range
Danfoss
3N1062
K
v
values are always given for water ow in [m
3
/h] with a pressure drop ∆p of 1 bar.
The valve should be selected so that the necessary k
v
value lies in the middle of the regulation range.
Example:
AVTA 10 and 15 are the most suitable for a k
v
value of 0.7
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Thermostatic operated water valve, Type AVTA
Danfoss
3N1443
A
(bar)
(m3/h)
B
A
B
Pressure drop across valve
Capacity with fully open valve
Danfoss
3N1437
A B C
A
B
C
Universal sensor
Mass sensor
Adsorption sensor
Figure 10: Valve ow quantity in fully open position, as a function of pressure drop Δp.
Options
• DZR brass
• Outer thread connecting
• Other lengths of capillary tubes
• Armouring of capillary tubes
• Other combinations of sizes, materials and ranges
• NPT – connection, see separate datasheet for USA / Canada
Dimensions and Weights
Figure 11: Types of sensor
Thermostatic operated water valve, Type AVTA
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193
A B C
Danfoss
3N1438
A
B
C
Brass/Stainless steel pockets
for universal sensor
Stainless steel pockets for
mass/adsorption sensor
Brass pocket for mass/
adsorption sensor
Figure 12: Valves in brass and stainless steel housings
Dimensions [mm] and weights [kg] of AVTA valves in brass and stainless steel housings
Table 3: Dimensions and Weights
Type
H
1
H
2
L
L
1
a
b
Net weight
AVTA 10
240
133
72
14
G 3⁄8
27
1.45
AVTA 15
240
133
72
14
G 1⁄2
27
1.45
AVTA 20
240
133
90
16
G 3⁄4
32
1.5
AVTA 25
240
138
95
19
G 1
41
1.65
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Thermostatic operated water valve, Type AVTA
Ordering
AVTA with adsorption charge
Figure 13: Sensor installation
The charge consists of active carbon and CO
2
which is adsorbed on falling sensor temperature, thereby producing a
pressure change in the element.
• Wide regulating range
• Can be installed in any position as far as orientation and temperature are concerned
• Small sensor dimensions – ø9.5 × 150 mm
• Max. pressure on sensor 25 bar
For immersion pockets, see Accessories and Spare parts.
Table 4: AVTA with adsorption charge
Connection
(1)
Regulating range
Max. temp.sensor
k
v
value
Capillary tube
length
Type
Code no.
(2)
[°C]
[°C]
[m
3
/h] at Δp = 1 bar
[m]
G 3⁄8
10 – 80
130
1.4
2.3
AVTA 10
003N1144
G 1/2
10 – 80
130
1.9
2.3
AVTA 15
003N0107
G 1/2
10 – 80
130
1.9
2.3 (armoured)
AVTA 15
003N2114
G 3/4
10 – 80
130
3.4
2.3
AVTA 20
003N0108
G 1
10 – 80
130
5.5
2.3
AVTA 25
003N0109
(1)
ISO 228-1.
(2)
Code no. covers complete valve incl. capillary tube gland.
(1)
ISO 228-1.
(2)
Code no. covers complete valve incl. capillary tube gland.
Thermostatic operated water valve, Type AVTA
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Figure 14: Sensor installation Figure 15: Valve body with bypass
AVTA with universal charge
The charge is a mix of liquid and gas where the liquid surface (regulating point) is always inside the sensor. Which
charge medium is used depends on the regulation range.
• Sensor dimensions ø18 × 210 mm
• Sensor can be installed in a place where it is either colder or warmer than the valve
• Sensors must be orientated as shown in the sketch below
• Max. pressure on sensor 25 bar
For immersion pockets, see
Accessories and Spare parts.
Table 5: AVTA with universal charge
Connection
(1)
Regulating range
Max. temp.sensor
k
v
value
Capillary tube
length
Type
Code no.
(2)
[°C]
[°C]
[m
3
/h] at Δp = 1 bar
[m]
G 3⁄8
0 – 30
57
1.4
2
AVTA 10
003N1132
G 1/2
0 – 30
57
1.9
2
AVTA 15
003N2132
G 3/4
0 – 30
57
3.4
2
AVTA 20
003N3132
G 1
0 – 30
57
5.5
2
AVTA 25
003N4132
G 3⁄8
25 – 65
90
1.4
2
AVTA 10
003N1162
G 1/2
25 – 65
90
1.9
2
AVTA 15
003N2162
G 1/2
25 – 65
90
1.9
2.0 (armoured)
AVTA 15
003N0041
G 3/4
25 – 65
90
3.4
2
AVTA 20
003N3162
G 3/4
25 – 65
90
3.4
5
AVTA 20
003N3165
G 3/4
25 – 65
90
3.4
2.0 (armoured)
AVTA 20
003N0031
G 1
25 – 65
90
5.5
2
AVTA 25
003N4162
G 1
25 – 65
90
5.5
2.0 (armoured)
AVTA 25
003N0032
G 1
25 – 65
90
5.5
5
AVTA 25
003N4165
G 3⁄8
50 – 90
125
1.4
2
AVTA 10
003N1182
G 1/2
50 – 90
125
1.9
2
AVTA 15
003N2182
G 3/4
50 – 90
125
3.4
2
AVTA 20
003N3182
G 1
50 – 90
125
5.5
2
AVTA 25
003N4182
G 1
50 – 90
125
5.5
3
AVTA 25
003N4183
(3)
(1)
ISO 228-1.
(2)
Code no. covers complete valve incl. capillary tube gland.
(3)
A ø2 mm bypass is drilled in the valve body.
(1)
ISO 228-1.
(2)
Code no. covers complete valve incl. capillary tube gland.
(3)
A ø2 mm bypass is drilled in the valve body.
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Thermostatic operated water valve, Type AVTA
AVTA with mass charge
Figure 16: Sensor installation
The charge is a mix of liquid and gas. Due to the mixture of liquid and gas the sensor must be installed in an area or
environment that is warmer than the valve.
• Small sensor dimensions – ø9.5 × 180 mm
• Short time constant
• Max. pressure on sensor 25 bar
Table 6: AVTA with mass charge
Connection
(1)
Regulating range
Max. temp.sensor
k
v
value
Capillary tube
length
Type
Code no.
(2)
[°C]
[°C]
[m
3
/h] at Δp = 1 bar
[m]
G 1⁄2
0 – 30
57
1.9
2
AVTA 15
003N0042
G 3⁄4
0 – 30
57
3.4
2
AVTA 20
003N0043
G 1⁄2
25 – 65
90
1.9
2
AVTA 15
003N0045
G 1⁄2
25 – 65
90
1.9
2.0 (armoured)
AVTA 15
003N0299
G 1⁄2
25 – 65
90
1.9
5
AVTA 15
003N0034
G 3⁄4
25 – 65
90
3.4
2
AVTA 20
003N0046
G 1
25 – 65
90
5.5
2
AVTA 25
003N0047
(1)
ISO 228-1
(2)
Code no. covers complete valve incl. capillary tube gland.
(1)
ISO 228-1
(2)
Code no. covers complete valve incl. capillary tube gland.
AVTA in Stainless Steel with adsorption charge
Figure 17: Sensor installation
Thermostatic operated water valve, Type AVTA
© Danfoss | Climate Solutions | 2021.03 AI193586424671en-000901 | 14
Danfoss
3N9005
• Wide regulating range
• Can be installed in any position as far as orientation and temperature are concerned
• Small sensor dimensions – ø9.5 × 150 mm
• Max. pressure on sensor 25 bar
• AVTA SS mass and universal charges available on request
For immersion pockets, see Accessories and Spare parts.
Table 7: AVTA in Stainless Steel with adsorption charge
Connection
(1)
Regulating range
Max. temp. sensor
k
v
value
Capillary tube
length
Type
Code no.
(2)
[°C]
[°C]
[m
3
/h] at Δp = 1 bar
[m]
G 1⁄2
10 – 80
130
1.9
2.3
AVTA 15
003N2150
G 3⁄4
10 – 80
130
3.4
2.3
AVTA 20
003N3150
G 1
10 – 80
130
5.5
2.3
AVTA 25
003N4150
(1)
ISO 228-1.
(2)
Code no. covers complete valve incl. capillary tube gland.
(1)
ISO 228-1.
(2)
Code no. covers complete valve incl. capillary tube gland.
Accessories
Table 8: Accessories
Designation
Description
Code no.
Danfoss
3N9000
Immersion sensor
Max. pressure 50 bar
L = 220 mm
Brass for ø18 sensor G ¾
003N0050
Brass for ø18 mm, sensor ¾ – 14 NPT
003N0051
18/8 steel
(1)
for ø18 sensor, ¾ – 14 NPT
003N0053
18/8 steel
(1)
for ø18 sensor R ¾
003N0192
Danfoss
3N9001
Immersion sensor
Max. pressure 50 bar
L = 182 mm
Brass for ø9.5 sensor G ½
017-436766
18/8 steel
(1)
for ø9.5 sensor R ½
003N0196
Danfoss
3N9002
Mounting bracket
For AVTA
003N0388
Danfoss
41E9000
Heat-conductive compound
5 gram tube
041E0110
0.8 kg
041E0111
Set of 3 nitrile (NBR) diaphragms sets for min-
eral oil
For AVTA 10/15, 20, 25
003N0448
Danfoss
17-9008
Capillary tube gland
G ½
017-422066
G ¾
003N0155
½ – 14 NPT
003N0157
¾ – 14 NPT
003N0056
Plastic hand knob
For AVTA
003N0520
(1)
W. no. 1.4301.
(1)
W. no. 1.4301.
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Thermostatic operated water valve, Type AVTA
Spare parts
Figure 18: Thermostatic elements for AVTA valves
Danfoss
3N1103
Table 9: Spare parts
Thermostatic Elements
Temperature range
Capillary tube length
Code no.
[°C]
[m]
Adsorption charge – sensor ø9.5 × 150 mm
10 – 80
2.3
003N0278
Universal charge – sensor ø18× 210 mm
0 – 30
2
003N0075
0 – 30
5
003N0077
25 – 65
2
003N0078
25 – 65
5
003N0080
50 – 90
2
003N0062
Mass charge – sensor ø9.5 × 180 mm
25 – 65
2
003N0091
25 – 65
5
003N0068
Thermostatic operated water valve, Type AVTA
© Danfoss | Climate Solutions | 2021.03 AI193586424671en-000901 | 16
Certicates, declarations, and approvals
The list contains all certicates, declarations, and approvals for this product type. Individual code number may have
some or all of these approvals, and certain local approvals may not appear on the list.
Some approvals may change over time. You can check the most current status at danfoss.com or contact your local
Danfoss representative if you have any questions.
Table 10: Certicates, declarations, and approvals
File name
Document type
Document topic
Approvals Authority
003N9617.AA
Manufacturers Declaration
PED/RoHS
Danfoss
003N9614.AA
Manufacturers Declaration
China RoHS
Danfoss
RU Д-DK.БЛ08.В.00191_18
EAC Declaration
EAC
EAC
UA.089.D.00188-17
UA Declaration
TYSK
TYSK
© Danfoss | Climate Solutions | 2021.03 AI193586424671en-000901 | 17
Thermostatic operated water valve, Type AVTA
Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its
products without notice. This also applies to products already on order provided that such alterations can be made without subsequential
changes being necessary in specications already agreed. All trademarks in this material are property of the respective companies. Danfoss and
the Danfoss logotype are trademarks of Danfoss A/S. All rights reserved.
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