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Construction
The GEMU 658/688 2/2 way or multi-port metal diaphragm valve has a two stage actuator.
The actuator has a stainless steel housing and is controlled by two pistons working independently of each other

Features
  • Suitable for inert, corrosive, liquid and gaseous media
  • Chemical resistance of actuator
  • CIP / SIP cleaning and sterilizing capabilities
  • An adjusting screw in the actuator head enables the setting of the opening and closing function and also the setting of a part stroke (for reduced flow)
  • Quick ON/OFF operation and the possibility for precision dosing of the working medium
  • Insensitive to particulate media
  • Valve body and diaphragm available in various materials and designs
  • Various connections available
  • Compact design
Advantages
  • Optional flow direction, will seal in either flow direction up to full working pressure
  • Optional mounting position
  • Can be individually used. Space consuming piping systems and valve wiring are no longer necessary
  • Extensive range of accessories (e.g. pilot valves, limit switches, field bus connections)

Specifications

Type 658 688
Nominal Size DN 10 DN 15 DN 20 DN 25 DN 32 DN 40 DN 50
Body Configuration Multi-Port Design Straight through T Valve Body Tank bottom valve body
Connection Butt Weld Spigots ASME BPE Butt Weld Spigots BS 4825, Part 1 Butt Weld Spigots DIN Butt Weld Spigots DIN 11850, Series 1 Butt Weld Spigots DIN 11850, Series 2 Butt Weld Spigots DIN 11850, Series 3 Butt Weld Spigots DIN 11866, series A Butt Weld Spigots EN ISO 1127 Butt Weld Spigots JIS-G 3447 Butt Weld Spigots JIS-G 3459 Butt Weld Spigots SMS 3008 Clamp ASME BPE for pipe ASME BPE length EN 558-1, series 7 Clamp ASME BPE for pipe ASME BPE, short design Clamp DIN 32676 for pipe DIN 11850 length EN 558-1, series 7 Clamp following ASME BPE for pipe EN ISO 1127, length EN 558-1 series 7 Clamp SMS 3017 for pipe SMS 3008 length EN 558-1, series 7 Flanges DIN 2501, form C length EN 558-1, series 1 One side threaded spigot, other side cone spigot with union nut, DIN 11851 Threaded Sockets DIN ISO 228 Threaded spigots DIN 11851
Valve Body Material 1.4408 Cast stainless steel 1.4435 (316 L) Block material 1.4435 (316 L) Forged body 1.4435 (ASTM A 351 CF3M) 34 Investment casting (Material equivalency 316L)
Diaphragm Material EPDM, max.150°C EPDM, max.150°C EPDM, max.150°C EPDM, max.150°C FPM, max.130°C PTFE/EPDM convex, PTFE loose, max.150°C PTFE/EPDM, PTFE laminated, max.150°C PTFE/FPM convex, PTFE loose, max.150°C PTFE/Silicon convex, PTFE loose, max.160°C
Control Function Normally closed
Design Diaphragm size 10 Diaphragm size 25 Diaphragm size 40+50
Surface Finish1 Ra ≤ 0.25 µm, electropolished internal/external Ra ≤ 0.25 µm, mechanically polished internal, blasted external Ra ≤ 0.4 µm, electropolished internal/external Ra ≤ 0.4 µm, mechanically polished internal,blasted external Ra ≤ 0.6 µm, electropolished internal/external Ra ≤ 0.6 µm, mechanically polished internal, blasted external Ra ≤ 0.8 µm, electropolished internal/external Ra ≤ 0.8 µm, mechanically polished internal, blasted external Ra≤ 6.3 µm, blasted internal/external Ra≤ 6.3 µm, electropolished internal/external

Working Medium

Working Medium2 Corrosive, inert, liquid and gaseous media which have no negative impact on the physical and chemical properties of the body and diaphragm material.
Working Temperature Max. 150 ºC

Control Medium

Control Medium Inert Gases
Max. Perm. Temperature of Control Medium 60 ºC

Note

N/A The valve will seal against flow in either direction up to full working pressure (gauge pressure).

  • 1 Ra acc. to DIN 4768; at defined reference points
  • 2 Depending on medium wetted materials.