The GEMÜ R690 diaphragm valve has a low maintenance membrane actuator which can be controlled by air or inert gases. Normally Closed (NC), Normally Open (NO) and Double Acting (DA) control functions are available. All medium wetted parts and the actuator housing are made of high-grade plastic materials which can be selected to suit the application.


  • Suitable for inert and corrosive* liquid and gaseous media
  • Insensitive to particulate media
  • Optional flow direction and mounting position
  • Nominal pressure PN 10 / 150 PSI
  • Nominal size DN 15 - DN 100 / NPS 1/2" - NPS 4"
  • Actuator housing in glass fibre reinforced PP
  • Valve body and diaphragm available in various materials and designs


  • Compact, lightweight construction and high performance
  • Good flow characteristics due to flow optimized valve body
  • Proven long-life membrane actuator
  • Leak detection hole
  • Diaphragm easy to replace
  • Adjusted instrumentation
  • Optical position indicator as standard
  • Optional accessories

- Electrical position indicator with microswitches or proximity switches
- Positioner and process controller
- Stroke limiter
- Pilot valve


Type R677
Nominal Size DN 100 DN 15 DN 20 DN 25 DN 32 DN 40 DN 50 DN 65 DN 80
Body Configuration 2/2-Way
Connection Flanges ANSI CLASS 125/150 RF, length EN 558, series 1, Flanges EN 1092 / PN10 / form B, length EN 558, series 1, ISO 5752, basic series 1 Spigots - inch for socket solvent cementing/welding Spigots DIN for socket solvent cementing/welding Spigots for IR butt welding Union ends with DIN insert (socket) Union ends with inch insert - BS (socket) Union ends with Rp threaded socket inserts
Valve Body Material ABS Inliner PP-H grey / outliner PP reinforced (DN 15 - 50) Inliner PVDF / outliner PP reinforced (DN 15 - 50) PP, reinforced (DN 65 - 100) PVC-U, grey PVDF (DN 65 - 100)
Diaphragm Material EPDM FPM NBR other diaphragm material on request PTFE/EPDM, PTFE laminated
Ambient Temperature Valve body ABS -10 to 50°C Valve body PP 5 to 50°C Valve body PVC-U 10 to 50°C Valve body PVDF -5 to 50°C

Working Medium

Working Medium Corrosive, inert, gaseous and liquid media which have no negative impact on the physical and chemical properties of the body and diaphragm material.
Temperature of Working Medium1 Valve body ABS -20 to 60°C Valve body PP 5 to 80°C Valve body PVC-U 10 to 60°C Valve body PVDF -10 to 80°C
  • 1 The permissible operating pressure depends on the working medium temperature.