Danfoss AVTA Data sheet

Data sheet

Thermo. operated water valve AV TA

Thermo. operated water valves are used for proportional regulation of ow quantity, depending on the setting and the sensor temperature.

The Danfoss range of thermo. 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.

Features • Insensitive to dirt

• Insensitive to water pressure

• Needs no power supply – self acting

• Opens on rising sensor temperature

• Dierential pressure: 0 – 145 psi

• Maximum working pressure (MWP): 232 psi Maximum test pressure: 365 psi

• Maximum pressure on sensor: 365 psi

• Stainless steel version available

• The valves are pressure-relieved, i.e. the 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: -13 – 266 °F

• Ethylene glycol as a cooling media up to 40%

Data sheet | Thermo. operated water valve, AVTA

3N1103.13

Danf

3N1101.13

How it works

Thermo. operated water valves consist of three main elements:

1. Setting section with knob, reference spring and setting scale.

2. Valve body with orice, closing cone and sealing elements.

3. Hermetically sealed thermostatic element with sensor, bellows and charge.

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:

1

1. The pressure changes in the sensor as a result of a change in temperature - builds up in the sensor.

2. This pressure is transferred to the valve via the capillary tube and bellows and acts as an

oss

opening or closing force.

3. The knob on the setting section and the spring exert a force that acts counter to the bellows.

Danfoss

3N1102.12

2

4. When balance is created between the two opposing forces, the valve spindle remains in its position.

5. 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

3

open or closed.

6. The ow quantity change is approximately proportional to sensor temperature change.

The illustrations show an AVTA cooling water valve, but the function principle applies to all types of thermostatic valves.

Danfoss

AVTA applications 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:

y Injection moulding machines y Compressors y Vacuum pumps y Dry cleaning machines y Distillation plants y Printing machines y Hydraulic systems y Roller mills y Biomass boilers y Industrial lasers y Steam sterilizers y Medical equipment y Food processing

1. Oil tank

2. Hydraulic machinery

3. Heat exchangers

4. Cooling water supply

5. ATVA thermostatic valve

Data sheet | Thermo. operated water valve, AVTA

Danfoss

Materials

AVTA

6

3N158.11

2

5

3

4

1

2

7

Charges

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

ATVA thermo. operated water valves with dierent types of charge

Universal charge Mass charge

Adsorption charge

Data sheet | Thermo. operated water valve, AVTA

Ordering AVTA with adsorption charge

Sensor installation

For immersion pockets, see “Spare parts and accessories”, page 8.

The charge consists of active carbon and CO is adsorbed on falling sensor temperature, thereby producing a pressure change in the element.

2

which

y Wide regulating range y Can be installed in any position as far as

orientation and temperature are concerned y Small sensor dimensions – ø0.4 × 5.9 in y Max. pressure on sensor 365 psi

Connection

NPT [in]

½ - 14 50 – 176 266 2.2 7.6 AV TA 15 0 03N6115

¾ - 14 50 – 176 266 4.0 7.6 AV TA 20 003N7120

1 - 11 ½ 50 – 176 266 6.4 7. 6 AV TA 25 003 N8125

1)

Code no. covers complete valve incl. capillary tube gland.

Regulating

range

[°F] [°F] US [gpm] [ft]

Max. temp.

sensor

kv value

Capillary

tube length

Typ e Code no.1)

Data sheet | Thermo. operated water valve, AVTA

Ordering AVTA with universal charge

Sensor installation Valve body with bypass

For immersion pockets, see “Spare parts and accessories”, page 8.

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.

y Sensor dimensions ø0.7 × 8.3 in y Sensor can be installed in a place where it is

either colder or warmer than the valve y Sensors must be orientated as shown in the

sketch below y Max. pressure on sensor 365 psi

Connection

NPT [in]

½ - 14 32 – 86 135 2.2 6.6 AV TA 15 003N 6132

1 - 11 ½ 32 – 86 135 6.4 6.6 AV TA 25 003N8132

½ - 14 77 – 149 194 2.2 6.6 AV TA 15 003N6162

¾ - 14 77 – 149 194 4.0 6.6 AV TA 20 003N7162

1 - 11 ½ 77 – 149 194 6.4 6.6 AV TA 25 003N8162

½ - 14 122 – 194 257 2.2 6.6 AV TA 15 003 N6182

¾ - 14 122 – 194 257 4.0 6.6 AV TA 20 003N7182

1 - 11 ½ 122 – 194 257 6.4 6.6 AV TA 25 003 N8182

1)

Code no. covers complete valve incl. capillary tube gland.

Regulating

range

[°F] [°F] US [gpm] [ft]

Max. temp.

sensor

Cv value

Capillary

tube length

Typ e Code no.1)

Data sheet | Thermo. operated water valve, AVTA

Ordering AVTA with mass charge

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.

Connection1)

Regulating

range

Max. temp.

sensor

Cv value

y Small sensor dimensions – ø0.4× 7.5 in y Short time constant y Max. pressure on sensor 365 psi y Only codes with G thread available

Capillary

tube length

Typ e Code no.1)

[°F] [°F] US [gpm] [ft]

2

G 1⁄

G 3⁄

G 1⁄

G 3⁄

4

2

4

32 – 86 135 2.2 6.6 AV TA 15 003N0042

32 – 86 135 4.0 6.6 AV TA 20 003N0043

32 – 86 135 6.4 6.6 AV TA 15 003N0045

77 – 149 194 2.2 6.6 AV TA 15 003N0034

77 – 149 194 4.0 6.6 AV TA 20 003N0046

G 1 77 – 149 194 6.4 6.6 AV TA 25 003N0047

1)

Code no. covers complete valve incl. capillary tube gland.

Data sheet | Thermo. operated water valve, AVTA

Ordering AVTA in Stainless Steel with adsorption charge

Sensor installation

For immersion pockets, see “Spare parts and accessories”, page 8.

y Wide regulating range y Can be installed in any position as far as

orientation and temperature are concerned

y Small sensor dimensions – ø0.4 × 5.9 in

Regulating

Connection1)

2

G 1⁄

4

G 3⁄

G 1 50 – 176 266 6.4 7. 6 AV TA 25 003N4150

1)

Code no. covers complete valve incl. capillary tube gland.

range

[°F] [°F] US [gpm] [ft]

50 – 176 266 2.2 7.6 AV TA 15 003N2150

50 – 176 266 4.0 7.6 AV TA 20 003N3150

Max. temp.

sensor

Cv value

y Max. pressure on sensor 365 psi y AVTA SS mass and universal charges available on

request y Only codes with G thread available.

Capillary

tube length

Typ e Code no.1)

Data sheet | Thermo. operated water valve, AVTA

3N1103.13

Accessories

1)

W. no. 1.4301.

Designation Description Code no.

Brass for ø0.7 in, sensor ¾ – 14 NPT 003N0051

18/8 steel 1) for ø0.7 sensor, ¾ – 14 NPT 003N0053

Immersion sensor

Brass for ø0.4 sensor G ½ 017-436766

max. pressure 725 psi L = 7.2 in

18/8 steel1) for ø0.4 sensor R ½ 003N0196

Mounting bracket Fo r AV TA 003N0388

Heat-conductive compound

0.01 lbs tube 041E 0110

1.75 lbs 041 E0111

Set of 3 nitrile (NBR) diaphragms sets for

For AVTA 10/15, 20, 25 003N0448

mineral oil

½ – 14 NPT 003N 0157

¾ – 14 NPT 003N0056

Plastic hand knob Fo r AV TA 003N0520

Spare parts Thermostatic elements for AVTA valves

Danfoss

Thermostatic Elements

Adsorption charge – sensor ø0.4 × 5.9 in 50 – 176 7’ 6” 003N0278

Universal charge – sensor ø0.7× 8.3 in

Mass charge – sensor ø0.4 × 7.5 in

Temperature range Capillary tube length

[°F] [ft]

32 – 86 6’ 6” 003N0075

32 – 86 16’ 5” 003N0077

77 – 149 6’ 6” 003N0078

77 – 149 16’ 5” 003N0080

122 – 194 6’ 6” 003N0062

77 – 149 6’ 6” 003N0091

77 – 149 16’ 5” 003N0068

Code no.

Data sheet | Thermo. operated water valve, AVTA

Installation

AVTA with mounting bracket

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 “Spare parts and accessories”, page 10 – it must always be positioned between the valve body and the setting section (see illustration).

Data sheet | Thermo. operated water valve, AVTA

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.

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:

y Necessary cooling at full load 5 TR. y Oil temperature to be maintained constant at 113 °F y Cooling water p1 = 60 psi y Outlet p3 = 0 psi

3

p1+p

y p2 = y Cooling water temperature t1 = 88 °F

2

(guess)

y Outlet temperature t2 = 68 °F

Valve size

The following data are used when selecting the valve size:

y Required cooling water ow, Q [US [gpm]] y Temperature rise in cooling water, Δt [°F] y Dierential pressure across valve, Δp [psi].

With fully open valve, the dierential pressure should be around 50% of the total pressure drop across the cooling system.

The charts on page 12 are intended to make valve sizing easier.

Fig. 1 – Relation between heat quantity [kW] and

cooling water quantity Fig. 2 – Graphs of Cv values Fig. 3 – Valve operating range Fig. 4 – Flow quantities as a function of pressure

drop Δp

Operating conditions and other product requirements in this example mean that a valve with adsorption charge is the correct choice. The temperature range 50 – 176 °F is in order.

The table on page 4 gives AVTA 15, code no.0 03N 6115, which fulll the requirements. To facilitate the installation a sensor pocket is often used. A sensor pocket for ø0,4” sensor in brass, code. no. 017- 436766, or in stainless steel, code no. 003N0196, is listed under “Accessories” on page 10.

1. Using the graph in g.1, you nd the necessary cooling water quantity at Δt = 20 °F (88 – 68 °F) for 6 US [gpm].

2. Using the graph in g. 2, you nd the necessary Cv-value for 6 US [gpm] at Δp = 30 psi (60 – 0)/2) for 1.17 US [gpm].

3. It can be seen from the columns in g.2 that all three AVTA valves ca n be used, but the preferable selection is a valve where the necessary Cv-value lies in the middle of the range. So in practice an AVTA 15 ought to be selected as it fully meets the demand.

Data sheet | Thermo. operated water valve, AVTA

3N1318.12

Danfoss

3N1319.11

Sizing

(continued)

Fig. 1 Heating or cooling with water.

Example:

Necessary cooling output 5 TR with t = 20 °F. Required ow is 6 US [gpm].

Fig. 2 Relation bet ween water quantity and pressure drop across valve.

Danfoss

Example: Flow 6 US gpm with a pressure drop of 30 psi. The Cv value becomes 1.17 US [gpm].

Data sheet | Thermo. operated water valve, AVTA

Danf

3N1062.12

3N1317.12

Sizing

(continued)

Fig. 3 Nomogram showing the valve Cv ranges.

oss

Cv values are allways water ow in US gpm for a pressure drop Δp of 1 psi. The preferable selection is a valve where the necessary Cv-value lies in the middle of the range, as a valve with a Cv-value close to either the max. or min. value is less stable and less precise due to either a relatively large Δp or ΔQ.

Example:

AVTA 10 and 15 are the most suitable for a Cv value of 1.17 US [gpm].

Danfoss

Fig. 4 Valve ow quantity in fully open position, as a function of pressure drop Δp.

Options y DZR brass

y Outer thread connecting y Other lengths of capillary tubes y Armouring of capillary tubes y Other combinations of sizes, materials and

ranges

y NPT – connection, see separate datasheet for

USA / Canada

Dimensions [in] and weights

3/4 - NPT

3N1438.10

0.79

2.17

0.7

5.9

[lbs] of AVTA valves in brass and stainless steel housings

0.4

8.3

7.5

oss

Universal sensor Mass sensor Adsorption sensor

Brass/Stainless steel pockets

for universal sensor

3/4 - NPT

8.82

8.66

8.7

1/2 - NPT

0.43

7.6

1/2 - NPT

Stainless steel pockets for

mass/adsorption sensor

1/2 - NPT

0.43

8.27

7.17

1/2 - NPT

Brass pocket for

Danfoss

Typ e H

1

AV TA 15 9.45 5.24 2.84 0.56 G 1⁄

AV TA 20 9.45 5.24 3.55 0.63 G 3⁄

H

2

L L

1

a Net weight

2

4

3.20

3.31

AV TA 25 9.85 5.43 3. 74 0.75 G 1 3.64

Danfoss AVTA Data sheet

Specifications and Main Features

Frequently Asked Questions

User Manual