I was just curious, the lines that go into my outdoor Carrier CAC unit
there looks like 2 valves(?) with caps on them which say " turn 1/6 of
a turn after making contact with gasket".
My neighbors on either side of me have identical Lennox units that say
" turn 1/12 of a turn after making contact with the gasket".
What are these caps for and why is it critical to tighten them
They are connections where you can hook up the test guages and fill the unit
with Freon (what most people call the refrigerant gas). The caps are just
to help seal up the valve outlet so the gas will not come out, and also to
protect the threads from dammage and getting dirt in the system when the
gauges are hooked up.
All fittings should be tightened correctly to prevent dammage to the
I'm not sure if you are referring to the shraeder valves, which are on
the sides of these " capped valves". The schraeder valves have caps on
them. These caps I am referring to are about 1" wide.
I saw the A/C tech last time hook up the gauges to the schraeder
valves. Are you saying that the bigger capped valves are another point
to connect the gauges?
Actually, the caps you're talking about are the covers for the service
valves. When a condensing unit is shipped from the factory, it has
refrigerant in it. The installers braze the refrigerant lines on, pressure
test the joints, evacuate the lines with a vacuum pump and open the service
valves. Then they're supposed to put the caps back on the service valves
and tighten them to make sure the refrigerant doesn't leak out that way.
Sounds like a king valve. Used to isolate system components when you need
to open up the system. They seal to the atmosphere if all-the-way-open or
all-the-way-closed, while partly-open leaks very slowly; thus the
instructions for opening and closing.
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