At NICET's official website, under the programs tab, there is information regarding NICET testing. There one can find out more about NICET testing, fees, and how to schedule the test.
Fire Tech Productions (www.firetech.com) offers NICET training. Their new NICET BASICS text book contains a 45 page chapter on Intermediate Math. Many problems are worked out and illustrated so a user can learn and have detailed examples during the exam. Fire Tech Productions can be reached at 937-790-6143 or email info@firetech.com or visit their website at www.firetech.com. Online courses for Intermediate Math are also available in case you need to have that element unlocked.
In order to obtain a NJ State Fire Sprinkler License you will have to meet the following requirements: Achieve a NICET Level II certification in Water Based Inspection, Testing and Maintenace Pass and verify 19 specific elements of NICET Sprinkler layout. Fill out an aplication thru the NJ Fire and Safety Division with your NICET Level II certificate and a NICET transcript showing those 19 elements passed.
In general, any device powered by the fire alarm panel must be listed as compatible with it. There are probably few, if any gas shutoff valves so listed, so probably not. The normal arrangement for this function is to use auxiliary contacts, either on the panel itself or an intelligent control module to switch an external power supply. This connection should be wired "fail safe" meaning the valve would close if the external power failed. If you asked this question, you are probably not qualified to design fire alarm systems. This is a life safety system! Get a qualified engineer or NICET IV designer to make sure you have it right. There are numerous codes, standards, and local amendments that must be followed, as well as the manufacturer's guidelines.