Travis S

Just got done installing my new Mighty Mouse catch can. I opened up the block post on the A&A intake tube per instructions. I also capped the valley port. So after the install I started to wonder what keeps the fresh air side from reversing under pressure. I would presume that both valve cover ports would have equal pressure under boost (refer to shity drawing number #2) so is there something that stops the pressure from entering the intake tube, ie check valve on the oil reservoir or should there be a check valve in line between the passenger side valve cover and the oil reservoir. Drawing 1 shows what I believe happens under normal vacuum from what I have read. Just a curiosity question, but would like to know that I am just not moving where the intake indigest oil and fumes into the system.

Thanks for the input in advance
Travis

PS: I do not make a living as an artist or with my penmanship, if I did this question would be about a Subaru, LOL.