Here is a list of some background research done on several different types of valves, including their pros and cons, in order to determine which will be the best solution for our design: valves_2.pdf
The following resources were used in the making of this chart:
http://goliath.ecnext.com/coms2/gi_0199-116274/Pick-the-right-valve-know.html
http://www.engvalves.com/itemfiles/valveselectionessentials.pdf
http://www.valvias.com/type-diaphragm-valve.php