Danfoss AVTA Thermostatic Valve User Guide

Quick guide from the manual

The Danfoss AVTA is a thermostatic valve designed for temperature-controlled flow regulation. This document provides essential instructions for installation, sensor placement, and system maintenance. Proper installation is critical for accurate regulation and system longevity.

Installation

The valve can be mounted in any position, but flow must follow the direction indicated by the arrow on the valve body. It is recommended to install a dirt filter (e.g., Danfoss type FV) upstream of the valve.

• Mounting bracket: If using a mounting bracket (code no. 003N0388), it must be placed between the setting unit and the valve body, never between the valve body and the bellows element.
• Capillary tube: Install without sharp bends and provide strain relief at the ends, especially in environments prone to vibration.

Sensor Positioning

For quick and precise regulation, the entire sensor surface must be in contact with the medium. Using a sensor pocket (code no. 003N0050) filled with copper paste (code no. 041E0110) improves heat transfer.

• Large sensor: Mount so the free end is lower or at the same level as the capillary tube connection. If mounted horizontally, ensure the "UP" mark faces upwards.
• Small sensor: Mount so the free end is higher than the capillary tube connection. It must be placed in a warmer location than the medium flowing through the valve.
• Note: These orientation limitations do not apply to elements with adsorption charges.

Operation and Adjustment

Use the adjustment knob to set the desired temperature at the sensor. Verify the temperature with a thermometer near the sensor. Turning the knob anticlockwise increases the temperature, while clockwise rotation decreases it.

Maintenance

After installation, flush the pipeline to remove impurities by forcing the valve open. Insert two screwdrivers through the holes in the setting unit and press the spring retainer upwards to open the valve.

Replacement of Bellows Element

The bellows element can be replaced without draining the system:

1. Set the valve to 1.
2. Loosen the four screws holding the bellows element to the valve body.
3. Remove the element and install the new one, ensuring the pressure stem centers on the valve spindle.