Frequent cycling of valves (open-close) commonly result in wear and tear of their closure members. The Nether Seal   Non Contact Rising Stem Ball Valve (RSBV) has especially been designed to be installed in frequent cycling processes.The non contact design prevents wear and tear and result in long lifetime operation.  At Nether Seal we have been successfully testing our RSBV at elevated temperatures and process design conditions in an endurance test with over 30.000 cycles.   

Nether Seal RSBV valves have passed the Fire Safe tests by independent inspection agencies successfully. Nether Seal Non Contact Rising Stem Ball Valves are available with hand wheel or gear operator as well as electric, pneumatic or hydraulic actuators. All Nether Seal RSBV valves will be designed and produced to client specific requirements. Our 2G Helix designed turning mechanism assures a smooth operation and exceptional long lifetime compared to others.

Advantages of the Nether Seal design are:


  • Customized selection of corrosion and wear resistant materials.
  • Heavy wall thickness (in excess to ASME B16.34) includes corrosion allowance.
  • Single Seat design.
  • Friction free closing and opening, extended lifetime.
  • Self cleaning closure members due to high velocity flow during opening and closing.
  • In-line inspection and maintenance possible due to top-entry design.
  • Linear movement of stem, no rotation.
  • Non lubricated seal.
  • Stem packing is adjustable while valve is in service. 
  • Back Seat is available in all valves, renewal of stem packing  under pressure is possible.