an elastomeric o ring 38 is provided between ladd 11 and the adjacent face of stationary member 30 a seal in the form of an elastomeric o ring 48 is provided in the counterbore and is disposed between the adjacent radial face of thrust washer 42 and radial land 57 the axial distance between radial lands 11 and 57 defines the finite axial extent of the seal member receiving chamber upon attachment of fitting 44 to threads 20 with radial stop surface 15 of body 12 in engagement with radial stop surface 51 of fitting 44 seals namely o rings 38 and 48 are placed in compression between the seal assembly and the radial lands 11 and 57 the seals provide a fluid tight seal against the associated radial faces of the seal assembly and the radial stop surfaces 11 and 57 and also provide a predetermined preload upon the discs to urge the contacting faces into fluid tight contact with each other though o ring seals are illustrated it is contemplated that a variety of seals could be used any form of packing is considered acceptable it is also thought that expandable elastomeric or metallic bellows could be substituted for the o ring seals illustrated the stationary seal member 30 is pinned to body 12 by pin 70 fig5 it includes a pair of flow ports 34 as shown in fig4 although two ports 34 are illustrated the actual number and size of the ports may vary depending upon the flow conditions of the application the rotatable seal member 32 also has a pair of flow ports.