Danfoss Thermostatic Operated Water Valve Type AVTA
Data Sheet
Opens on rising sensor temperature
Introduction
Thermostatic operated water valves are used for proportional regulation of flow quantity, depending on the setting and the sensor temperature. The Danfoss range of thermostatic operated water valves includes products for both refrigeration and heating regulation. These valves are self-acting, meaning 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
This design maximizes operating economy and efficiency.
AVTA SS for aggressive media: A valve body in stainless steel allows the valve to be used for aggressive media, such as in the marine sector and the chemical industry.
Features
- Insensitive to dirt
- Insensitive to water pressure
- Needs no power supply – self-acting
- Opens on rising sensor temperature
- Differential 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, meaning the degree of opening is not affected by differential pressure Δp (pressure drop).
- The regulation range is defined for the point at which the valve begins to open.
- Cooling media temperature range: -25 – 130 °C
- Suitable for ethylene glycol as a cooling media up to 40%.
Functions: How it works?
When the three elements (setting section, valve body, and sensor) are assembled, installed, and the sensor is placed at the point where temperature regulation is needed, the function sequence is as follows:
- The pressure in the sensor changes as a result of a temperature change, building up pressure within the sensor.
- This pressure is transferred to the valve via a capillary tube and bellows, acting as an opening or closing force.
- A knob on the setting section and a spring exert a force that counteracts the bellows.
- When a balance is created between these two opposing forces, the valve spindle remains in its position.
- If the sensor temperature changes or the settings are adjusted, the balance point shifts, causing the valve spindle to move until balance is re-established, or the valve is fully open or closed.
- The flow quantity change is approximately proportional to the sensor temperature change.
Figure 1 shows an AVTA cooling water valve, but the function principle applies to all types of thermostatic valves.
- Setting section with knob, reference spring, and setting scale.
- Valve body with orifice, closing cone, and sealing elements.
- Hermetically sealed thermostatic element with sensor, bellows, and charge.
Applications
AVTA thermostatic operated water valves are widely used for temperature regulation in many machines and installations where cooling is required. AVTA cooling water valves always open to admit flow on rising sensor temperature.
The valve can be installed in either the cooling water flow line or the return line. The standard version of the AVTA thermostatic 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
Diagram illustrating a typical application setup including:
- Oil tank
- Hydraulic machinery
- Heat exchangers
- Cooling water supply
- AVTA thermostatic valve
Product Specification: Materials
Diagram showing a cross-section of the AVTA valve with numbered components corresponding to the materials table.
Table 1: Materials
| No. | Description | Material AVTA | Material AVTA SS |
|---|---|---|---|
| 1 | Spindle | Brass | Stainless steel |
| 2 | Diaphragms | Rubber – ethylene – propylene (EPDM) | |
| 3 | Valve body and other metal parts | Forged brass | Stainless steel |
| 4 | Valve seat | Stainless steel | |
| 5 | Valve cone | Nitrile rubber (NBR) | |
| 6 | Sensor | Copper | |
| 7 | Capillary tube gland | Nitrile rubber (NBR) / brass | |
Types of charges
Table 2 lists the different types of charges available for AVTA thermostatic operated water valves:
- Universal charge
- Mass charge
- Adsorption charge
Installation
AVTA with mounting bracket
Diagram showing the AVTA valve, possibly with a mounting bracket, indicating installation orientation.
The valves can be installed in any position. An arrow on the valve body indicates the direction of flow. 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 filter ahead of the valve is recommended.
Capillary tube
Install the capillary tube without sharp bends (no "kinks"). Ensure 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-off valve might be necessary to ensure flow at the sensor during start-up. If a mounting bracket is used, it must always be positioned between the valve body and the setting section.
Sizing
When sizing and selecting thermostatic operated water valves, it is crucial to ensure the valve can provide the necessary quantity of cooling water at any time, irrespective of the load. This requires knowing the precise amount of cooling needed. Conversely, to avoid unstable regulation (hunting), the valve should not be oversized.
The type of charge must be selected based on the temperature to be maintained and an assessment of the characteristics of each type. Generally, select the smallest valve capable of providing the required flow. It is also recommended to choose a temperature range so that the required sensor temperature falls in the middle of the regulation range.
To aid fine-setting, a thermometer should be installed near the sensor.
Valve size
The following data are used when selecting the valve size:
- Required cooling water flow, Q [m³/h]
- Temperature rise in cooling water, Δt [°C]
- Differential pressure across valve, Δp [bar]
Sizing Charts and Example
With the valve fully open, the differential pressure should be around 50% of the total pressure drop across the cooling system.
The following charts 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 value range
- Figure 10: Valve flow quantity in fully open position, as a function of pressure drop Δp.
Example: Cooling water valve for a vacuum pump
A cooling water valve is to 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: 45 °C
- Cooling water inlet pressure (p₁): 3 bar
- Cooling water outlet pressure (p₃): 0 bar
- Approximate pressure at valve inlet (p₂): (p₁ + p₃) / 2 = (3 + 0) / 2 = 1.5 bar (guess)
- Cooling water temperature (t₁): 20 °C
- Outlet temperature (t₂): 30 °C
Using Figure 7 (Heating or cooling with water), the necessary cooling water quantity at Δt = 10 °C (30 °C - 20 °C) is found to be 0.85 m³/h.
Figure 8 (Relation between water quantity and pressure drop across valve) shows the necessary k value for 0.85 m³/h with Δp = p₁ - p₂ = 3 - 1.5 = 1.5 bar is approximately 0.7 m³/h.
Figure 9 (Nomogram showing the valve k value range) indicates that all four AVTA valve sizes can be used. However, for practical purposes, an AVTA 10 or AVTA 15 is selected, placing the necessary water flow in the middle of the regulating range.
These considerations apply to both AVTA and FJVA types.
Based on operating conditions and product requirements, a valve with an adsorption charge is the correct choice for this example. The temperature range 10 – 80 °C is suitable.
Table 4 (AVTA with adsorption charge) lists AVTA 10 (code no. 003N1144) or AVTA 15 (code no. 003N0107) as fulfilling these requirements.
In many applications, installation conditions make the use of sensor pockets advisable. Accessories section provides code numbers for sensor pockets for Ø9.5 mm sensors in brass (017-436766) and stainless steel (003N0196).
Diagram illustrating the typical connection of the AVTA valve in a system, showing pressure and temperature points (P1, P2, P3, T1, T2).
A chart plotting cooling water flow rate (Q in m³/h) against temperature difference (Δt in °C) for various cooling outputs (kW).
Example: Necessary cooling output 10 kW with Δt = 10 °C requires a flow of 0.85 m³/h.
Valve Sizing Charts
A chart showing water flow rate (Qy in m³/h) plotted against pressure drop (Δp in bar), with lines indicating different k values.
Example: Flow 0.85 m³/h with a pressure drop of 1.5 bar corresponds to a k value of approximately 0.7 m³/h.
A nomogram to determine the appropriate AVTA valve size (AVTA 10, 15, 20, 25) based on the required k value. K values are given for water flow in [m³/h] with a pressure drop Δp of 1 bar.
Example: AVTA 10 and 15 are the most suitable for a k value of 0.7.
A chart showing flow rate (B in m³/h) plotted against pressure drop (A in bar) for different AVTA valve sizes (AVTA 10, 15, 20, 25).
Options and Dimensions
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
Diagrams illustrating three types of sensors: A - Universal sensor, B - Mass sensor, C - Adsorption sensor, showing their physical characteristics and connection types.
Diagrams showing the physical dimensions of AVTA valves in brass and stainless steel housings, with labels for different sensor pocket types (A, B, C).
Table 3: Dimensions and Weights
| Type | H₁ [mm] | H₂ [mm] | L [mm] | L₁ [mm] | a | b | Net weight [kg] |
|---|---|---|---|---|---|---|---|
| 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 |
Ordering
AVTA with adsorption charge
Diagram showing sensor installation for AVTA with adsorption charge.
The adsorption charge consists of active carbon and CO₂, which is adsorbed on falling sensor temperature, thereby producing a pressure change in the element.
- Wide regulating range
- Can be installed in any position regarding orientation and temperature.
- Small sensor dimensions – Ø9.5 x 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 [°C] | Max. temp.sensor [°C] | kv value [m³/h] at Δp = 1 bar | Capillary tube length [m] | Type | Code no.(2) |
|---|---|---|---|---|---|---|
| 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.
AVTA with universal charge
Diagram showing sensor installation for AVTA with universal charge.
Diagram showing a valve body with a bypass feature.
The charge is a mix of liquid and gas where the liquid surface (regulating point) is always inside the sensor. The charge medium used depends on the regulation range.
- Sensor dimensions: Ø18 x 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.
- Max. pressure on sensor: 25 bar
For immersion pockets, see Accessories and Spare parts.
Table 5: AVTA with universal charge
| Connection(1) | Regulating range [°C] | Max. temp.sensor [°C] | kv value [m³/h] at Δp = 1 bar | Capillary tube length [m] | Type | Code no.(2) |
|---|---|---|---|---|---|---|
| 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.
AVTA with mass charge
Diagram showing sensor installation for AVTA with mass charge.
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 x 180 mm
- Short time constant
- Max. pressure on sensor: 25 bar
Table 6: AVTA with mass charge
| Connection(1) | Regulating range [°C] | Max. temp.sensor [°C] | kv value [m³/h] at Δp = 1 bar | Capillary tube length [m] | Type | Code no.(2) |
|---|---|---|---|---|---|---|
| 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.
AVTA in Stainless Steel with adsorption charge
Diagram showing sensor installation for AVTA in Stainless Steel with adsorption charge.
- Wide regulating range
- Can be installed in any position regarding orientation and temperature.
- Small sensor dimensions – Ø9.5 x 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 [°C] | Max. temp. sensor [°C] | kv value [m³/h] at Δp = 1 bar | Capillary tube length [m] | Type | Code no.(2) |
|---|---|---|---|---|---|---|
| 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.
Accessories
Table 8: Accessories
| Designation | Description | Code no. |
|---|---|---|
| Immersion sensor | Brass for Ø18 sensor G 3/4 | 003N0050 |
| Immersion sensor | Brass for Ø18 mm, sensor 3/4 – 14 NPT | 003N0051 |
| Immersion sensor | 18/8 steel(1) for ø18 sensor, 3/4 – 14 NPT | 003N0053 |
| Immersion sensor | 18/8 steel(1) for Ø18 sensor R 3/4 | 003N0192 |
| Immersion sensor | Brass for Ø9.5 sensor G 1/2 | 017-436766 |
| Immersion sensor | 18/8 steel(1) for Ø9.5 sensor R 1/2 | 003N0196 |
| Mounting bracket | For AVTA | 003N0388 |
| Heat-conductive compound | 5 gram tube | 041E0110 |
| Heat-conductive compound | 0.8 kg | 041E0111 |
| Set of 3 nitrile (NBR) diaphragms sets | for mineral oil For AVTA 10/15, 20, 25 | 003N0448 |
| Capillary tube gland | G 1/2 | 017-422066 |
| Capillary tube gland | G 3/4 | 003N0155 |
| Capillary tube gland | 1/2-14 NPT | 003N0157 |
| Capillary tube gland | 3/4-14 NPT | 003N0056 |
| Plastic hand knob | For AVTA | 003N0520 |
(1) W. no. 1.4301.
Spare Parts
Diagram showing the thermostatic elements used in AVTA valves.
Table 9: Spare parts
| Thermostatic Elements | Temperature range [°C] | Capillary tube length [m] | Code no. |
|---|---|---|---|
| Adsorption charge – sensor Ø9.5 x 150 mm | 10–80 | 2.3 | 003N0278 |
| Universal charge – sensor Ø18× 210 mm | 0–30 | 2 | 003N0075 |
| Universal charge – sensor Ø18× 210 mm | 0–30 | 5 | 003N0077 |
| Universal charge – sensor Ø18× 210 mm | 25–65 | 2 | 003N0078 |
| Universal charge – sensor Ø18× 210 mm | 25–65 | 5 | 003N0080 |
| Universal charge – sensor Ø18× 210 mm | 50–90 | 2 | 003N0062 |
| Mass charge - sensor Ø9.5 x 180 mm | 25–65 | 2 | 003N0091 |
| Mass charge - sensor Ø9.5 x 180 mm | 25–65 | 5 | 003N0068 |
Certificates, Declarations, and Approvals
The list contains all certificates, declarations, and approvals for this product type. Individual code numbers 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: Certificates, 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 -DK.08..00191_18 | EAC Declaration | EAC | EAC |
| UA.089.D.00188-17 | UA Declaration | TYSK | TYSK |
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