First issue to be be resolved is if the cylinders you have can be equipped with a regulator which will reduce the internal pressure down to anywhere between 12 to 18 PSI to the keg. If there is a regulator for these tanks, pressure to the keg is determined by brand of beer, beer temperature and elevation. For example, a Miller draught product at 38 degrees dispensed at sea level requires 14 PSIG. The temperature is critical.
Scott Zuhse, Instructor
Micro Matic Dispense Institute