A leak free floating packing shaft seal is provided for a rotatable shaft d a supporting annular structure wherein the supporting annular structure has a high pressure upstream side and a low pressure downstream side. The floating seal includes an annular holder which is slidably mounted in the supporting...http://www.google.es/patents/US4572518?utm_source=gb-gplus-sharePatente US4572518 - Leak free floating packing shaft seal
