Double Eccentric Butterlfy valves with PN16 & PN25
A double offset butterfly valve called as DEX valve, Double Eccentric Butterfly valves, valve body seat is offset to the front side of the body, and the disc is offset to the front side of the shaft.it is applied in the raw water long distance transportation, water treatment, drinking water distribution projects.
| STANDARD | OPTION | |
| Design | EN 593 Double Flanged, Double Eccentric | |
| Nominal Sizes | DN 100 - DN2500 | 4“ to 100" |
| Pressure Rating | PN 10, PN 16, PN 25, | 150 PSI 150PSI 228PSI 350PSI |
| Medium | Potable water, raw water | Sea water |
| Face To Face | EN 558 – 1 SERIES 13 | EN 558 – 1 SERIES 14 |
| Flanges | EN1092-1 | ANSI B16.5; ASME B 16.47 Series A AWWA C207 |
| AS 2129 – AS4087; SABS 1123, Gramaphone grooved raised face flange | ||
| Material | ||
| Body | Ductile Iron | WCB, CF8, CF8M, DUPLEX SS2205 /2507 |
| Disc | Ductile Iron+Nickel Plated | Al-Ni bronze, CF8M, 4A, 5A |
| Sealing Ring | EPDM rubber | NBR, PTFE |
| Shaft | Stainless steel | 17-4PH,F51, F55 |
| Body Seat | 304 Stainless steel weld overlay & micro finished | Chrome nickel overlay & 316 & rubber lined, DUPLEX SS2205/2507 |
| Retaining Ring | 316 Stainless steel | ST 37 Carbon Steel, AI-Ni bronze Internal Fixings |
| External Fixings | Stainless steel | |
| Bearing Bush | Bronze + Delrin | NI-AL bronze + Delrin |
| Coating | Epoxy coated, min. 500 Microns thickness | Two pack epoxy, solvent free epoxy, coal tar epoxy Operation |
| Work Temperature | According to EN 1074 | |
| Colour | RAL 5005 | Ask for other colours |
| Closing Direction | Anticlockwise close | Clockwise |
| Operation | Manual by worm gearbox and handwheel | Electric, Pneumatic, Hydraulic, Actuator |
Body
Streamline design and smooth finish of the body provides minimum resistance to flow.
Disc
Streamlined and low profiled disc including closed hubs ensuring higher kv values. Double offset disc design reduces seal wear and torque.
Sealing system
Sealing on seat face is ensured by an endless T profile resilient sealing ring which is held on the periphery of the disc by a retaining ring. In closed position the sealing ring is pressed against the conically shaped seat face of the body and provides safe sealing in either direction of flow. In opened position the sealing ring is completely unstressed due to the double eccentric disc design.
Retaining ring
The one piece retaining ring prevents sealing ring from rolling out. Sealing ring can be replaced easily at site without dismantling the valve disc and without requirement of any special tool.
The Design of the Double Eccentric
FEATURES
- Stainless steel dry shaft completely sealed off by rubber O-rings
on sealing sleeve and dry pins.
- Teflon lined filament wound bearings for long service life and
lower operating torque
- Double-Eccentric design optimizes the seal of the seat retaining
ring allowing the disc to seal tightly while retaining the seat in
position against high pressure and flow
- Specially engineered seat sealing system adds to longer service life
and lower operating torque.
Application:
Double eccentric butterfly valves are most often used in water supply applications below ground as an alternative to gate valves. When installing butterfly valves below ground a lower bury depth is required and typically, they are more cost-effective, especially in the large dimensions, compared to gate valves. They can of course also be used above ground.
photo for Double Eccentric Butterlfy valves with face to face Series 13, Large size
Portable Butterfly valves with Double Eccentric Design, Length to EN558 Series 14
Ebonited Double Eccentric Butterlfy valves with rubber lined, for sea water desalination, face to face length to AWWAC504
