Coker-SchieberCoker Valve延迟焦化工业阀门Клиновые задвижки типа
ProductsPetrochemical and Refining IndustriesCoker Valve
Update time: 22.01.2015

Innovative Coker Valves unheading/ deheading

Coker unit - Deheading/ Unheading and Isolation Valves


Z&J offers complete solutions for Delayed Coking Units.

The systems are manufactured in Double Disc Design and available as:

  • Bottom Unheading Valves
  • Top Unheading Valves
  • Inlet Isolation Valves
  • Quench and Blowdown Valves

Main Advantages of the Double Disc Through Conduit Gate Valve

  • Real double block and purge performance within one valve body due to two independent discs. 
  • Active mechanical sealing force due to central split-wedge-ball arrangement. 
  • Corrosion and wear resistant hard facing overlay on the seats; no adjustment and replacement of seats required.
  • No deposits of solid particles in valve body due to valve gates guided between guide plates. 
  • All wear parts can be easily removed when the valve is in maintenance position.
  • The sealing surfaces are completely covered in each gate end position. Depositing within the valve and on the seats is avoided.
  • Disc carrier equipped with tube to provide throughway in open position.
  • Purge steam connection for continuous valve body and seat purge.
  • Minimum purge consumption due to reliable metal seating even under hot oil in situation.
  • Emergency manual operation integrated.
  • Extremely low purge steam consumption.


  • During deheading/unheading no personnel are required on deck due to fully remote operation. 
  • Real double block and purge due to two independent discs. Highly reliable sealing even during hot oil in phase. 
  • No spillage of coke or drum water onto the unheading deck due to fixed oultlet shute below the valve.


  • Well proven design used in other severe services such as ethylene, FCCU, phosgen, etc. 
  • The design assures long term operation. Clogging of coke chunks, residue or any other foreign matters are avoided.
  • The actuator is well over designed to assure 100% opearbility in open as well as closed position, even in most severe situations.
  • Field service is extremely easy and can be done in very short timing.
  • Coke feed lines remain mounted.
  • No gasket changing is necessary after each drum cycle like during manual unheading.
  • Drum water dainage through the open valve can be configured.