I hate to burst your bubble here guys, but those "Direct Acting Valves" are not legal for 2007 FIRST robots. <R46>, as well as
this question in the Q&A pretty much cover the use of non-air operated solenoid valves.
A non-air operated solenoid valve uses an electronic solenoid, which is considered to be a motor in the eyes of the GDC. What Keith has suggested is to make your own non-air operated solenoid valve using kit parts/motors. His solution of adapting a servo to rotate a manual shut-off valve is the perfect solution to this problem. Other motors could be used (globe, window) but they would also require a spike, limit switches, etc... The servo trumps all of that in terms of weight and simplicity.
We had a hard time dissecting the rules to determine which solenoid valves were legal and which were not. Through a few online searches, we were unable to find low-cost, low-weight, pressure rated air-operated solenoid valves. More than likely, we'll be using the servo solution.
BEN