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. 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

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

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

3N158.11

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.

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

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)

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