I would like to track our gas cylinder rental. We rent gas cylinders for use in brazing AC copper pipe, cutting torches, welding, balloons, and beverage dispensers. The need is real since the cylinders come and go as they are used. We are charged a rental rate and a charge for the gas. I would like to enter them as tools and issue them out to personnel. Then when they bring in empties to swap out with full reissue a new tank. I can account for the cost of the gas, but how do I charge for the rental fee?