Hey Danny I'm pretty sure that this is a low pressure check valve:
http://www.fourmost.com/auto_plg.htm
I wish that Eric would confirm this.
I know it's working for you now but I would take the attitude that it has a potential to cause a problem. From the pictures of your flying site in Aruba I wouldn't want too many deadsticks in a heavy wind. Tell Jock that Mike said hi please. Mike Mueller