Restriction?

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Dougflas
Posts: 260
Joined: Mon Apr 18, 2016 6:10 pm

Re: Restriction?

Postby Dougflas » Sat Oct 19, 2019 12:49 pm

TXV sensing bulb is upside down. The entrance of the capillary should be pointed up to make sure liquid does not influence the TXV diaphragm. If I was doing this, I would change the TXV. The vertical line (left side of picture) is the input of the TXV. The TXV line at 3 o'clock position is the TXV outlet which should go to the input of the evap. The TXV is the point where hot and cold takes place. So the outlet of the TXV (right hand line at 3 o'clock) should be cold. And the sensing bulb needs to be insulated.

Take the sensing bulb loose and place it in a cup of ice water. Monitor your pressures. After a minute or two, the pressures should change. Then place the bulb in warm water. The pressures should change. If not, replace the TXV.
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bohica2xo
Posts: 660
Joined: Wed May 11, 2016 4:12 pm
Location: Las Vegas, NV

Re: Restriction?

Postby bohica2xo » Sun Oct 20, 2019 10:13 am

A blockage at the TXV would result in a reduced low side pressure as the refrigerant stacked up in the receiver dryer.

If the TXV was restricted you should see calm liquid in the sight glass.

The receiver is designed to deliver liquid to the TXV. If the flow is reversed it does a lousy job of that. And what you see in the sight glass is the condenser discharge, rather than the liquid being delivered to the TXV.

Where exactly are the ports located in this system? The insane high side pressures make me suspect the condenser.

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