VESTNIK of Samara University. Aerospace and Mechanical EngineeringVESTNIK of Samara University. Aerospace and Mechanical Engineering2542-04532541-7533Samara National Research University30110.18287/2541-7533-2006-0-2-1(10)-69-74UnknownSome features of seals with spring preloaded semi-movable rings calculation11sadohina@ssau.ru1807200652-1697420052014Copyright © 2015, VESTNIK of the Samara State Aerospace University2015<p>The seals with semi-movable rings are widely used in rocket engines pumps. One of abnormal function of this seals causes is contact of rotor and stator elements. This occurs due to incorrect selection of seal clearance or because the rotor makes the ring to rotate in equal and opposite direction of rotor and ring rotation. Use of the axial preload by spring in the semi-movable seal design is one of the ways to eliminate the semi-movable ring rotation in full range of turbopumps operation modes.</p>