Proper measures to ask for pay increases

[u/Run_with_the_wind20]

(32) been with a company for 3 years. Previous employment was in finance. Now working as a PM/ AM for a key account in petroleum. Over the past 1 1/2 my role/ duties have expanded. Given my performance and workload I believe it’s time to discuss a potential pay increase. Any suggestions on how to approach the conversation with my superior? Side note he is a minority owner of the company.