D671X Pneumatic Wafer Butterfly Valve
• Models: D671X-10/10Q/10C (PN10) and D671X-16/16Q/16C (PN16) — pneumatic actuated
• Size range DN50–DN500, double-acting or spring-return pneumatic actuator
• Body in gray cast iron, ductile iron, or WCB cast steel; Buna-N rubber seat
• 2Cr13 SS stem, ductile iron disc, aluminium bronze bushings
• Rated for water, steam, oil, weak acid and alkali up to 135 °C
Model: D671X Series | Pressure: PN10 / PN16 | Connection: Wafer (Pneumatic) | Medium: Water, Steam, Oil, Acid
Gaoshan Valve — D671X Pneumatic Wafer Butterfly Valve
Pneumatic actuated centerline wafer butterfly valve with rubber-lined disc, available in six body/pressure variants for automated water, steam, petroleum, and mild chemical service up to 135 °C. DN50–DN500.
Product Overview
The D671X is the pneumatic-actuated variant of the D71X wafer butterfly valve family, delivering fast, reliable remote automation for centerline-disc, rubber-seated butterfly valves from DN50 through DN500. A rack-and-pinion or scotch-yoke pneumatic actuator, available in double-acting and spring-return configurations, replaces the manual lever or gearbox, enabling integration into PLC/DCS control systems for water treatment plants, HVAC automation, fire protection, and industrial process lines. The same six body/pressure variants (PN10 and PN16, in gray cast iron, ductile cast iron, or WCB cast steel) and the same Buna-N elastomer seat provide proven bi-directional shutoff performance. Standard solenoid valve, limit switch, and positioner mounting interfaces come pre-machined for rapid field wiring.
Model Designation Guide
| Model | Pressure | Body Material | Operation |
|---|---|---|---|
| D671X-10 | PN10 | Gray Cast Iron (HT200) | Pneumatic (DA / SR) |
| D671X-10Q | PN10 | Ductile Cast Iron (QT450) | Pneumatic (DA / SR) |
| D671X-10C | PN10 | WCB Cast Steel | Pneumatic (DA / SR) |
| D671X-16 | PN16 | Gray Cast Iron (HT200) | Pneumatic (DA / SR) |
| D671X-16Q | PN16 | Ductile Cast Iron (QT450) | Pneumatic (DA / SR) |
| D671X-16C | PN16 | WCB Cast Steel | Pneumatic (DA / SR) |
Butterfly Valve Family — Operation Options
| Feature | D71X (Lever) | D371X (Gear) | D671X (Pneumatic) |
|---|---|---|---|
| Drive | Manual lever | Worm gear handwheel | Pneumatic actuator |
| Size range | DN40 – DN200 | DN50 – DN500 | DN50 – DN500 |
| Automation | Manual only | Actuator-ready pad | Fully automated (PLC/DCS) |
| Fail-safe | No | No (gearbox self-locking) | Yes (spring-return option) |
| Response time | Manual (slow) | Manual (multi-turn) | 3–15 sec (adjustable) |
Key Advantages
Technical Specifications
| Parameter | PN10 Models | PN16 Models |
|---|---|---|
| Nominal Pressure (PN) | 10 bar (1.0 MPa) | 16 bar (1.6 MPa) |
| Shell Test Pressure | 1.5 MPa | 2.4 MPa |
| Seal Test Pressure | 1.1 MPa | 1.8 MPa |
| Working Temperature | ≤ 135 °C | |
| Size Range | DN50 – DN500 | |
| End Connection | Wafer (between-flange, centerline) | |
| Operation | Pneumatic actuator (DA or spring-return) | |
| Actuator Air Supply | 0.4 – 0.7 MPa compressed air (clean, dry) | |
| Applicable Medium | Steam, water, petroleum, weak acid, alkali | |
| Design Standard | GB/T 13927 (pressure test); GB/T 12238 (face-to-face) | |
Materials of Main Parts
| Component | D671X-10 / -16 | D671X-10Q / -16Q | D671X-10C / -16C |
|---|---|---|---|
| Body | Gray Cast Iron (HT200) | Ductile Cast Iron (QT450) | WCB Cast Steel |
| Seat Ring | Buna-N Rubber (NBR) | ||
| Stem / Worm | 2Cr13 Stainless Steel | ||
| Disc | Ductile Cast Iron (QT450) | ||
| Axis Bushing | Aluminium Bronze | ||
| O-Ring Seal | Buna-N Rubber (NBR) | ||
Applicable Media
Water
Seawater
Petroleum
Fuel Oil
Weak Acid
Alkali
HVAC Water
Fire Protection
Principal Dimensions (mm) — PN10 / PN16
| Dim. | DN50 | DN65 | DN80 | DN100 | DN125 | DN150 | DN200 | DN250 | DN300 | DN350 | DN400 | DN450 | DN500 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| H1 | 68 | 82 | 85 | 105 | 128 | 138 | 175 | 205 | 245 | 265 | 295 | 326 | 345 |
| H2 | 118 | 140 | 150 | 180 | 200 | 210 | 245 | 280 | 320 | 340 | 380 | 420 | 460 |
| H3 | 115 | 132 | 132 | 132 | 155 | 190 | 190 | 222 | 265 | 265 | 265 | 265 | 265 |
| L | 43 | 46 | 46 | 52 | 56 | 56 | 60 | 68 | 78 | 78 | 102 | 114 | 127 |
| L1 | 185 | 240 | 240 | 240 | 285 | 340 | 340 | 445 | 505 | 505 | 505 | 505 | 505 |
H1 = centerline to top of body; H2 = centerline to top of actuator; H3 = actuator center height; L = face-to-face length; L1 = actuator length (along pipe axis). All values in mm. Main technical specifications and materials are identical to the D371X series. Flange connection dimensions refer to the standard flange dimension table. Air supply: 0.4–0.7 MPa clean, dry compressed air.
Product Structure Diagram
Pneumatic Actuator Configuration Options
| Option | Description |
|---|---|
| Double-Acting (DA) | Air pressure opens and closes the valve. No fail-safe position on air loss; last position is held. |
| Spring-Return Fail-Close (FC) | Air opens the valve; spring closes on air loss. Standard for safety-critical shutoff applications. |
| Spring-Return Fail-Open (FO) | Air closes the valve; spring opens on air loss. For processes where flow must be maintained on air failure. |
| Solenoid Valve | 5/2 or 3/2 NAMUR-mount solenoid pilot valve for remote electrical control. 24VDC / 220VAC coil options. |
| Limit Switch Box | Mechanical or proximity limit switches for open/closed position feedback to the control room. |
| Positioner | Electro-pneumatic positioner for 4–20mA modulating control and intermediate disc positioning. |
Quality Assurance & Testing
Every D671X pneumatic butterfly valve assembly undergoes the following factory acceptance tests:
- Shell Pressure Test — hydrostatic test at 1.5×PN to verify body integrity.
- Seat Leakage Test — air or water test at rated pressure; zero seat leakage per GB/T 13927.
- Actuator Stroke Test — full open-to-close cycling at minimum, nominal, and maximum air supply pressure to verify smooth operation and stroke time.
- Accessory Function Test — solenoid valve operation, limit switch signalling, and positioner feedback calibration verified as a complete assembly.
- Dimensional Inspection — face-to-face, flange, and actuator mounting dimensions checked against GB/T 12238 and NAMUR standards.
- Visual & NDT — casting and weld surfaces inspected; air piping leak-tested at 0.8 MPa.
Installation & Maintenance Notes
- Air supply quality: Use compressed air filtered to 40 µm and dew point at least 10°C below ambient. Install a coalescing filter and lubricator if plant air is oily or wet.
- Orientation: D671X valves may be installed in any pipe orientation. Avoid mounting the actuator upside down where condensation may enter the solenoid exhaust port.
- Flange bolts: Use through-bolts to clamp both pipe flanges together through the wafer body. Tighten in a cross pattern to avoid rubber seat distortion.
- Solenoid wiring: Connect solenoid coil to the plant emergency shutdown (ESD) loop if the valve provides a safety function. Verify fail-safe direction before commissioning.
- Stem packing: The stem uses O-ring sealing; no packing adjustment required. Replace O-rings if leakage detected during service.
- Periodic stroke test: Cycle the valve full stroke at least once per month (quarterly for infrequently operated valves) to prevent actuator seal stiction.
Ordering Information
| Item | Specify When Ordering |
|---|---|
| Model | D671X-10 / 10Q / 10C / 16 / 16Q / 16C |
| Nominal Size | DN50 – DN500 |
| Actuator Type | Double-acting (DA) or spring-return (FC / FO) |
| Air Supply Pressure | 0.4 – 0.7 MPa (standard); other on request |
| Accessories | Solenoid valve, limit switch, positioner (specify type) |
| Flange Drilling / Seat / Disc | GB/T 17241 (standard); NBR seat; ductile iron disc |
Request a Quote or Technical Support
Gaoshan Valve supplies D671X pneumatic wafer butterfly valves as fully assembled and tested packages — valve, actuator, solenoid, and accessories calibrated and ready to install. Contact our automation team for actuator sizing, torque calculations, and control schematics.