Quote Originally Posted by Refrigerologist
As I have said, if we are not to adjust the valve then the manufacturer would not bother to fit an adjustment screw
That's where I have a problem with adjusting stems. Just because the valve has one doesn't mean it should be turned!

Quote Originally Posted by Refrigerologist
I would suggest you look at a selection catalogue ...it will show that an orifice will provide different capacities at different conditions and the valve cannot be factory set to cover all of the possible conditions that the valve will need to cover!
I disagree!

The valve capacity changes because of the orifice size OR the pressure differential across the valve. The adjusting stem is to adjust the superheat for specific conditions. It is not used to adjust the valve capacity directly.