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Ethylene Transfer Line and Decoking Valves

Double disc technology – double block and purge

We are a world leader in Transfer Line Valves (TLV) & Decoking Valves (DV). IMI Z&J supplies high-quality Double Disc Through Conduit Gate valves which have higher safety levels than any other design. One double disc valve replaces two single gate valves – one plus one as backup installed in the same line to achieve the same safety Ievel.

  • Within the ethylene process heaters provide the cracking of hydro-carbons by means of hot steam. These heaters (steam crackers) suffer from a phenomenon where deposits of ‘coke’ accrue on the pipework and valves. From time to time these deposits must be removed (‘decoking’), ideally without shutting down the process completely. This is where our valves excel.


  • True double block & purge performance within one valve body by means of two independent, separate shut-off discs (independent closure elements). Proven under critical/severe service conditions.
  • Active, controlled and constant mechanical seating force when closed due to the central split-wedge-ball device with safe and reliable tight shut-off.
  • Flat or round body valve design.
  • Mounting options: flanges or welding ends.
  • With reduced or full-bore passage.
  • Long-lasting metal-to-metal seats, corrosion and wear resistant.
  • Smooth tubular passage ln the open position (valve body free of solid particles).
  • Can be installed in any orientation.
  • Designed to customer specifications and German or International standards.
  • Accommodates any desired type of actuator.

Product Specifications

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