I would say that vaccums are not subject to pneumatic rules:
Section 8.3.10 - R106 - For the purposes of the FIRST competition, a device that creates a vacuum is not considered to be a pneumatic device and is allowed. This includes, but is not limited to, Venturi-type vacuum generators and off-the-shelf vacuum devices (as long as they are powered by one of the Kit-of-Parts motors).
They are however subject to the laws of nature. The maximum pressure you can get from a vaccum is 14.7 PSI, atmophereic pressure.
I think I actually learned something in school.
