Gear Operated Wafer Butterfly Valves
A gear-operated wafer butterfly valve is formed by fitting a handwheel worm gearbox onto the stem of a wafer-bodied valve. The handwheel is turned many times to complete the quarter turn of the disc, so the operating torque that a lever cannot handle on large sizes is easily overcome by hand.
The gearbox manufacturer recommends a gearbox for DN150–DN300 and makes it mandatory from DN350 upwards. The valves in this group come in PN16 up to DN300 and PN10 for DN350–DN600, with stainless steel or aluminium bronze discs.
Main Applications
- Large-diameter water transmission and distribution lines
- Main header isolation in pumping stations
- Cooling tower and condenser water circuits
- Outlet lines of fire water tanks
- Basin inlets and outlets in treatment plants
- Main line points rarely operated but needing manual closing
Technical Data
| Connection | Wafer; clamped between two flanges |
|---|---|
| Size range | DN40–DN600, depending on model |
| Pressure class | PN16 (DN25–300) · PN10 (DN350–600), depending on model |
| Gearbox type | Quarter-turn handwheel worm gear |
| Gearbox mounting | ISO 5211 |
| Gearbox output torque | DN25–150: 170 Nm · DN200–250: 700 Nm · DN300–350: 1200 Nm · DN400–500: 2500 Nm · DN600: 4000 Nm |
| Handwheel diameter | 150 mm (DN25–150) · 300 mm (DN200–350) · 400 mm (DN400–450) |
| Stroke adjustment | 5% |
| Indicators | Open / closed position indicator |
| Gearbox ambient temperature | −20 / +70 °C |
| Valve operating torque (16 bar) | DN200: 194 Nm · DN300: 595 Nm · DN400: 1307 Nm · DN600: 3711 Nm |
| Medium temperature | EPDM −10 / +130 °C · NBR −10 / +80 °C, depending on model |
Material Options
| Part | PN10 · cast iron body, stainless disc | PN16 · GG25 body, stainless disc | PN16 / PN10 · ductile iron body, bronze disc |
|---|---|---|---|
| Valve body | Cast iron | Grey cast iron EN-GJL-250 (GG25) | Ductile iron EN-GJS-400-18 |
| Disc | Stainless steel AISI 316 | Stainless steel AISI 316 | Aluminium bronze |
| Stem | SS420 | SS420 (DN25–300) · SS431 (DN350–600) | SS420 (DN40–300) · SS431 (DN350–600) |
| Seat / liner | PTFE | EPDM | NBR |
| Gearbox body | Epoxy-coated ductile iron | Epoxy-coated ductile iron | Epoxy-coated ductile iron |
| Gearbox mounting | ISO 5211 | ISO 5211 | ISO 5211 |
The gearbox must be sized to cover the valve opening torque at the maximum working pressure with a safety margin. The stainless disc PN10 type is preferred up to DN300; the ductile iron body with bronze disc is preferred up to DN600 for seawater and brine lines.
Advantages
Low-Effort Operation
- Handwheel torque is multiplied by the gear ratio.
- Large sizes can be operated by one person.
Controlled Closing
- The disc turns over many handwheel revolutions.
- Reduces the risk of pressure surges from fast closing.
Visible Position
- Open-closed indicator on top of the gearbox.
- Valve status can be read from a distance.
Adjustable End Position
- 5% stroke adjustment.
- The disc seats correctly on the liner at full closure.
Construction and Design Features
- Wafer valve body clamped between flanges
- Worm gearbox connected to the stem via ISO 5211 flange
- Epoxy-coated ductile iron gearbox body with waterproof seal design
- Handwheel and open-closed position indicator
- End position adjustment screws
Request a quote for gear-operated wafer butterfly valves by stating size, pressure class, disc material and the required handwheel access side.
How to Choose?
- Match size and operatorA gearbox is recommended for DN150–DN300 and mandatory from DN350.
- Check the torqueMake sure the valve operating torque at 10 or 16 bar stays below the gearbox output torque.
- Plan handwheel accessChoose an installation position that keeps the handwheel within reach of the operator.
- Select disc and seatStainless disc for clean and chlorinated water, bronze disc for seawater; EPDM or NBR seat by temperature.
Complementary Products
Why ORFA?
Other Butterfly Valves
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Single Acting Pneumatic Lug Butterfly Valves
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Wafer Type Butterfly Valves
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Details →Our Gear Operated Wafer Butterfly Valves
ORFA supplies gear operated wafer butterfly valves in a range of pressure classes, sizes and connection types to suit your application. Descriptions, technical specifications, materials and dimension tables are available on each detail page.
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