txv expansion valve insulation

15 years ago

When insulating an expansion valve bulb after securing to the suction line, anyone know if there's a critical way to insulate it? Just wrap them both together, or try to cover as much copper as possible on each without wrapping in between the two? Maybe it doesn't matter as long as you've insulated? I've tried to cover as much as the copper as I can without separating the two with insulation where they meet, but was wondering if I could be interfering with the temperature sensing. Maybe I am over-thinking this.

Comments (6)

DNT1
15 years ago
If the line and bulb were cleaned and clamped to the line properly there is no way that you could put insulation between them. The temperature transfer is at the point of direct contact between the line and the sensing bulb. Wrap the insulation around the outside to your hearts content as long as it is properly cleaned and clamped it will work well.
kalining
15 years ago
Do you have the sensing bulb clamped at the right angle ?
You don't just clamp it in place and hope it works. Are you
using the proper clamps ? Don't even think of using hose
clamps. What have you done so far ?
Related Professionals
Prunedale Solar Energy Systems · West Hartford Solar Energy Systems · New Lenox Solar Energy Systems · Broomfield Home Automation & Home Media · El Monte Home Automation & Home Media · Hacienda Heights Home Automation & Home Media · Hanover Home Automation & Home Media · Los Alamitos Home Automation & Home Media · Oak Lawn Home Automation & Home Media · San Diego Home Automation & Home Media · West Palm Beach Home Automation & Home Media · Beaufort Fireplaces · Crystal Lake Fireplaces · Graham Fireplaces · San Tan Valley Fireplaces
eric_k
Original Author
15 years ago
Actually a professional put it on, it's clamped horizontally at 2 o'clock position. I believe he used clamps that came with it. Another question... I remember him saying the new expansion valve had a longer bulb than the old one, does that necessarily mean he put an incorrect valve on or could the bulb size vary by manufacturer? The new one has a label on it saying to use the same part which made me wonder about the difference in bulb size. It seems to be working. He did take the old one with him because originally he said he got the wrong one... took it with him so I'm hoping it is the right one and bulb size doesn't necessarily mean it's incorrect part???
miken_2008
15 years ago
Sounds like it is in the right position and yeah you are probably over thinking it if you just wrap it with foam tape or over wrap it with a larger piece of pipe insulation you should be fine you are just trying to keep the temperature of the ambient air from interfering with the pipe temperature the bulb is sensing

Here is a link that might be useful: Air Conditioning Repair made Easy
garyg
15 years ago
Eric:

The bulb should be at 10 or 2 o'clock per the install manual that I have.

There should be a "beer can" black foam blanket for the TXV itself. Mine came with that plus some black foam tape.

The TXV for the indoor coil is different for heat pump, straight a/c, 410, or R-22.

Good luck.
mr_havac
15 years ago
"There should be a "beer can" black foam blanket for the TXV itself."
AHH HA! I think gary just figured out why most HVAC techs consume vast quantities of beer! Especially those who do alot of work with TXV's :-)