API 653 D.2.1 gives the requirements to set for the test.
The test is given twice a year. The next one will be in March of 2013.
Here is the API web site
http://www.api.org/ICPThe test you will take will be one of the hardest you will ever take. You will not be able to skim the books and pass the test. Having taken the AWS/CWI twice, the 653 test is 4 time harder.
Nothing personal, but based on the fact you have never inspected a tank before in your life let alone for 5 years and are not a engineer who had overseen or inspected aboveground storage tanks for a year you are not qualified to sit for the test. However, the inspection company you are working for will in most instances sign off on the experience requirements and get it notorized.
Fill out the application, send API the test check, buy the books, take the Code West prep class, and you are as qualified as I am.
http://www.codewest.com/course-653.htmlOh, by the way, you will be out about $4 to $5K for the API books and counting lost time to take the prep class.
http://global.ihs.com/doc_detail.cfm?currency_code=USD&customer_id=2125482B390A&oshid=2125482B350A&shopping_cart_id=2125482B390A&country_code=US&lang_code=ENGL&item_s_key=00521560&item_key_date=991131&origin=CERTGood luck. And remember, as a inspector you only have 2 things to sell. Your integrity and what you know.