Sealing technology manual for the process industry - V-Seal set packings

V-SEAL SET PACKINGS V-Seal set packings are multi-part sealing sets primarily used in applications involving translatory motion. As they offer lower friction and require less pre-tensioning forces, they represent a worthwhile alternative to U-packings. V-Seal set packings normally consist of a compression ring, several V-shaped packing rings and a backup ring, providing reliable sealing for spindles on regulating and shut-off valves, rods on plunger pumps, hydraulic cylinders as well as swivel joints and mixers. Predominantly used with transla- tory motion but also with slow rotation, they generate less friction and require considerably less initial axial pretension- ing force than stuffing box packings, for instance. As the standard materials for V-Seal set packings are PTFE and PTFE-carbon compounds, they can be manufactured by machining from semifinished products in a particularly eco- nomical manner without the use of tools. Special-purpose V-Seal set packings made of PTFE-impregnated Nomex fab- ric require tools, but are also better suited for higher pres- sures, as they are less susceptible to cold flow. Freudenberg has a broad range of suitable tools in its inventory for this. Further materials such as polyethylene, PEEK and Univerdit (a compound of PTFE and graphite) are also available on request, as are specialized profiles, should none of the three standard options be compatible with the individual application. Function • Multi-part sealing set consisting of a compression ring, V-packing rings and a backup ring • Predominantly used with translatory motion, or occasion- ally with slower axial motion Dimensions Virgin PTFE and PTFE compounds: • Available in all inventory-standard dimensions • Special customer-specific dimensions are possible with- out difficulty PTFE fabric: • Extensive inventory of tools available • Special customer-specific dimensions available upon re- quest Installation and assembly Please refer to page 94 for general installation and assembly instructions. Primary applications • Regulation and shut-off valves • Dosing systems • Mixers • Pivot joints Predominantly used to seal • Spindles of control and regulation valves • Rods (translatory motion, possibly in combination with minor rotation) • Low-speed shafts THE ADVANTAGES AT A GLANCE • Highly variable to cover a broad range of applications • High pressure resistance (virgin PTFE and PTFE com- pounds up to 30 MPa, fabric-reinforced V-packing rings up to 70 MPa) • Very good temperature resistance (–200 °C to +260 °C (–328 °F to +500 °F)) • No tooling costs for virgin PTFE/PTFE compound variants • Adjustable set heights • Low friction • Universal chemical resistance • Low susceptibility to cold flow and extrusion in PTFE-fab- ric variant TYPES PTFE • DM 9403: stable profile for static sealing and pulsa- ting pressures up to 300 bar • DM 9406: relatively rigid lip profile for dynamic sealing and pressures up to 200 bar • DM 9409: flexible lip profile for dynamic sealing and pressures up to 50 bar as well as vacuum PTFE-fabric form-pressed • Packing rings made of PTFE-impregnated fabric • For certain applications packing ring combination of PTFE-impregnated fabric and virgin PTFE/PTFE compound for pressures up to 700 bar with low friction Product portfolio 78

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