A single-acting O-Ring energized piston seal with hydrostatic pressure relief channel for dynamic applications. It prevents pressure trapping between seals under all service conditions. Installed in closed grooves, including grooves to ISO 7425, Trelleborg Turcon® Stepseal® V offers high sealing efficiency. It also has low friction with no stick-slip, minimal break out force and high wear resistance. Stepseal® V is preferably used with Turcon® or Zurcon® piston seals.