Newbie RN ? about Lopez valve

Hi all,
I'm in my first week as a new RN on a medsurg floor. I only came across a Lopez valve two or three times in clinicals over two years. Now that I'll be seeing them much more often, I'm wanting to become more adept with them. I've googled their use and can never find a set of instructions; the websites I find are always down, and my nursing skills book doesn't address the valve.
Let's say the Lopez is on an NG tube. The off arrow points at the med/flush port.That means I can't give meds if memory serves me, correct? If I turn the off arrow toward the patient and the NG tube, then does that mean nothing can come out of the pt or nothing can come in to the pt? Likewise, if I turn the arrow toward the wall suction (the 3 o'clock position)?
And if I want to give meds to the pt, which direction do I turn the arrow? If I give meds, I don't have to disconnect anything, right, because the Lopez is used for just this purpose, but I DO have to turn off suction? Thanks for any help. There are sooo many things to know and remember!!
Why would you be giving any meds down an NG tube that is (or will shortly be) hooked up to suction? Why not just shoot 'em into the cannister and eliminate the middleman?That part needs clarification.

You will definitely have to turn off the suction when giving meds for at least 30 minutes (some will tell you an hour). Remember that anywhere the arrows on the lopez valve point are open, and anywhere the off section goes to is closed. So, if you want to flush or give meds, keep the off pointed at the red cap, take off the red cap, and hook up your syringe to that port. Then you flip the off section away from the patient (towards suction), so that the arrows are pointed towards your syringe and towards the patient. These areas are open and you can flush/give meds to the patient. Before you remove the syringe, point your off arrow back towards that direction. You learn which way the arrows go after a couple tries when you make a mess (at least I did).

Congratulations on the new job! Just want to stress to you that while you are orienting, to take advantage of all the help you can. You have a preceptor, right? You should be asking him or her ALL your questions. Don't be afraid to ask too many. Often we might be concerned when new people AREN'T asking questions. And ask different people, so you'll know who to talk to about trach care and who not to ask about wound care, etc. Also, hopefully your coworkers should be able to point you to a resource the facility uses. My hospital had a link to a skills website that had a database of nursings skills and procedures listed step by step, because even when your a seasoned nurse, you'll come across something you haven't seen before, or haven't seen in a year.

The way I remembered it when I was a new grad was the arrows are a road. If the arrows continue in a straight line then fluid, meds, or tube feeding can cross through "the road" but if I want to stop movement to the patient put the non arrow part closest to the patient.