TXV Bulb Placement - Short 109

HVAC School - For Techs, By Techs · Jan 26, 2021 · 12m

In this short podcast episode, Bryan talks about the placement of the TXV sensing bulb. He also explains how it affects the opening force on the TXV.

The TXV sensing bulb (or sensor on an EEV) provides the opening force for the valve. The warmer the bulb gets, the more the valve opens; the colder the bulb gets, the more the valve closes. The TXV also has a closing force provided by the spring pressure and equalizer (usually the external equalizer).

So, if you have a bulb that has been poorly mounted or insulated, you tend to have more opening force than the design. Your suction line will…