VA loan refinancing question

[Benjamin Kruah]

Greetings BP, 

I'm trying to get some information on refinance options wih the VA. I own a home that was purchased with the VA loan and would like to refi into a conventional loan. I have over 20% equity and was wondering if this is possible? If so how many times can I do this? I would like to eventually build a portfolio using this method of purchasing with VA then refinancing into conventional once I build equity. Is there a rule about how often the VA loan can be used?