In most cases, refilling a propane cylinder is a less expensive option than using an exchange program. Refilling the cylinder allows the owner to use any fuel remaining in the tank. In the United States, refillable propane cylinders must undergo a re-certification process 12 years after their manufacture date. If a RV cylinder needs re-certification, the distributor cannot refill it. The re-certified tank is good for an additional five years. Call us at 410-742-1957 for more information.