First time cash out refi

[Jeremy Lee]

Hello,

I am looking to cash out refi my duplex and use the funds to purchase another property. I have a few concerns and would like to get some input. 

Current mortgage is a FHA loan @ 4%. Current balance of about 90K. Based on comps, my estimated market value is 140-150K. My concern is, what if the appraisal value is not what I expect? Is it something where I just need to do it and see what happens? Can someone show the step by step process for this? Any advice would be appreciated. Thanks!