You *must not* pressurize this air tank over 200 PSI. Doing so is dangerous and may result in serious injury or death.
It is recommended to run these tanks at 150 PSI for the best performance.
Air tanks are not designed for use indefinitely. They must be replaced every 5-10 years or if signs of wear, stress, fatigue, or any sort of damage appear.
To ensure the longest use of your tank you should drain it regularly. Allowing condensate to build up in your tank will not only shorten the lifespan of your tank but is a safety concern.