Düker GmbH

Underground Hydrant 304 S


Application field

  • with spigot
  • DN 80
  • pipe covering 0.75 to 1.50 m
  • inside and outside enamelled
  • for drinking and raw water
  • up to 16 bar
  • up to 60°C
  • for TYTON® / Novo sockets

The underground hydrant type 304 S corresponds to all details and tests of the EN 14339 as well as the DVGW worksheet W331and has proven itself for years in drinking water supply, fire fighting and emergency water supply.

The most important elements

  • inside and outside enamelled one-piece body
  • ductile iron obturator with EPDM-coating
  • cast-on and fully enamelled drainage outlet
  • stainless steel rod
  • brass guide piece
  • stem nut (with rings)
  • stone protector
  • DIN outlet coupling with brass ring and cast protective cover with stainless steel chain
  • cast iron protector

Technical properties


The one-piece body of 304 S is made of fully enamelled ductile cast iron. The sturdy obturator allows ideal flow conditions and is also made of ductile cast iron with an all-around EPDM coating, permanently connected by vulcanization.


Düker underground hydrants are equipped with a protection against pressurised water: Once the hydrant is opened, the pressurised water will not enter the pillar from the main pipe before the drainage outlet of the pillar is locked. Following that same pattern, the drainage outlet will not open during the shut-off procedure until the main valve is securely locked. This prevents the leaking of pressurized water from the discharge outlet and allows the remaining residual water to


Type 304 S underground hydrant comes with a single shut-off device. This model requires the pipe to be pressure-free during installation.

Maintenance-free stem bearing through the use of two O-rings. The rolled stem thread ensures high wear resistance. A marking on the hydrant top (one to four cams) provides information about the pipe covering so that the pipe covering can also be determined any time after underground installation.

The built-in linkage safeguarding arrangement ensures secure installation and removal. Installation and operation to be carried out in accordance with the guidelines of the DVGW worksheet W 331.



For technical details please download our detailed catalogue.


Technical Information

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