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Diaphragm pressure relief valves and overflow valves with ball housing


( Technical information diaphragm pressure relief valves and overflow valves with ball housing as PDF-file)



Pressure relief valves

These valves can be used wherever it is necessary to maintain a certain pressure in a system.


During operation, as intended, a pressure relief valve is partially open.

  • To maintain a counter-pressure (initial pressure) during filling the tanks.
  • To maintain the line pressure in a ring line (e.g. fully demineralised water, demineralised water)
  • To maintain pressure in heat carriers to prevent bubble formation and the escape of dissolved gases or steam


Overflow valves

Overflow valves are completely closed during normal operation. These are safety devices without a type examination certificate or approval. They open automatically when the permissible pressure is exceeded. During cleaning they opened manuel or pneumaticaly.



  • Hermetic separation of product and operating chamber by controlled pressure on the diaphragm neck in the defined chamber of the seal area
  • Leakage opening for diaphragm leakage control
  • Diaphragm support ring for full pressure resistance, independent of flow duration
  • Ideal drainability
  • Minimum pressure losses
  • Excellent cleaning results due to no use of bellows or friction-related rod seals
  • Turbulent and laminar flow ensure optimized flow characteristics
  • CIP-/SIP-compatible
  • Valve housing of hot-rolled material for maximum production precision
  • Nominal sizes of DN 15, DN 25, DN 40, DN 50, DN 65, DN 80
  • Meets GMP requirements
  • Can be removed without spring tension
  • Finely adjustable, repeatable pressure setting


  • L- (angle) or Y-shaped
  • Cross housing
  • For welding on
    • short welding connection for manual welding
    • long welding connection for orbital welding
    • length of the connection piece according to customer's specifications
  • With pipe connections from the Nocado product lines
  • With pneumatic lifting for valve seat cleaning
  • With manual actuation for opening in cleaning position
  • With closed (leaded) cap,
  • With factory-adjusted actuation pressure (particularly for overflow valves)
  • End position feedback with
    • proximity initiators (also Namur)
    • mechanical limit switches
  • gasket material according to FDA directive
    • HNBR
    • EPDM
    • Viton

Nocado GmbH
Brendelweg 159
27755 Delmenhorst

Phone: +49 4221 800 99 830
Fax:       +49 4221 800 99 8930
sales@nocado.de |  www.nocado.de