Phillips 66 (PSX +1.10%) and its master limited partnership Phillips 66 Partners (PSXP +0.00%) have made the headlines recently, because of how high PSXP climbed during its first day of trading. It isn't the first refiner to find success with an MLP spinoff -- Marathon Petroleum's (MPC +0.56%) spinoff MPLX (MPLX +2.22%) is up more than 16% year to date -- and it doesn't look as if it will be the last. In this video, Fool.com contributor Aimee Duffy looks at Valero's (VLO 0.62%) recent affirmation of its plan to convert its logistics assets into an MLP.