TXV Bulb Placement
When mounting a TXV bulb or checking bulb placement there are a few important considerations (listed in order of importance)
- Mount the bulb on the suction line. Flapping in the breeze is no good.
- Mount TIGHTLY it with a proper metallic strap (usually copper or brass). Not zip ties, not tape.
- Position it on a flat, clean, smooth, portion of the horizontal suction line. Not on a coupling or an elbow.
- Mount it before the equalizer tube (closer to the evaporator than the EQ tube)
- When possible mount it at 8 or 4 o’clock on the suction line (or according to manufacturers specs) . This becomes more important the larger the suction line.
- When possible, insulate the bulb so that it is not influenced by ambient air temperature. It never hurts to insulate the bulb even inside the cabinet though not all manufacturers require it.
- If you do need to mount it vertically, make sure the tube points up not down
Poor bulb contact will result in a bulb that is warmer than desired, resulting in overfeeding and lower than desired superheat.
Finally… be gentle with the bulb and tube. They break easily.
You can read a more detailed description HERE
Bryan Orr is a lifelong learner, proud technician and advocate for the HVAC/R Trade