drain valve on water separator Gehl CTL 80

First, let me be honest. This is my first piece of equipment. I am trying to drain the water out of the separator bowl. The valve at the bottom just turns an nothing drains out . I loosed the vet screw at the top still nothing drains out. Is there a trick to this? I assume that the plastic valve should turn counter clockwise to drain, but it seems to turn either way, doesn't tighten or loosen. I know I can unscrew the plastic bowl, like I was changing the filter, but wanted that to be the last resort. Any help will be appreciated.

drain valve on water separator Gehl CTL 80