Abstract: The invention pertains to a vibration and sound isolator for pressurized conduit systems, such as refrigeration systems, capable of absorbing torsional and bending vibrations without fluid leakage. An annular cylinder casing defines a chamber receiving a tubular piston member having a head located within the chamber. The chamber is axially defined by a pressure face wall at one end, and a reaction wall at the other end. An annular elastomeric seal bonded to the piston head and reaction wall is compressed by fluid pressure acting upon the pressure face wall and piston head increasing the elastomer's resistance to fluid permeability. The axial dimension of elastomer intermediate the piston head and reaction wall permits torsional deflection between the cylinder and piston members about an axis coincident with fluid connection means defined upon the members, and radial clearance between the piston stem and elastomer permits related angular deflection of the members while maintaining a sealed relationship.