In present study, solution models for CTPS, CCPS, and LS were established to study radial pressure distribution of the seals and to analyze the effects of inlet/outlet pressure ratios and eccentricity ratios on floating concentric force. A floating self-concentric seal experiment apparatus was designed to study the effects of inlet/outlet pressure ratios and eccentricity ratios on response time and moving track of CTPS, CCPS and LS. The results show that CTPS has a good adaptive concentric performance, which is more suitable as a floating seal ring. Under different inlet/outlet pressure ratios and eccentricity ratios, CTPS always move towards concentric direction, and thereafter stabilizes at equilibrium location with a low eccentricity ratio, which is contributed to the greater floating concentric force counteracting friction force between the ball and plate. With the increase of inlet/outlet pressure ratio and eccentricity ratio, it takes a shorter floating response time to reach the equilibrium location.