Air filled model airplane tires are not steel belted or as rigid as automobile tires and can easily be over-inflated. They are durable and can provide many landings and years of use if you take basic care of them.
To inflate, acquire a small sports ball (basketball/football) hand pump (do not use a compressor or electric pump). Slide a piece of medium sized silicone fuel tubing over the pump attachment that inserts into the balls for inflation. On the other end of the tubing, insert the tire inflator. Next, thread the inflator into the valve in the tire being careful not to push the valve inside the tire.
Once complete, give 1-2 small bursts of air from the pump. When complete, immediately pinch off the tubing to stop the air from leaving the tire and unscrew the inflator from the tire. To confirm the tire is inflated properly, take all aircraft weight off the tire and measure the diameter. You should be close to the tire’s advertised size when properly inflated.
NOTE: For longest life, do not store aircraft with weight on the tires, elevate the plane so the tires are not holding the aircraft weight at all.