D942 Electric Double Eccentric Butterfly Valve
• D942F (PTFE seat) and D942X (rubber seat) electric double eccentric soft-seal butterfly valve, PN6/10/16
• Six seal materials: CR, NBR, EPDM, PTFE, Silicone, FKM — wide temp range −268 to +250 °C
• Size range DN80–DN1600 (nominal DN50–DN2000), flanged RF ends, short and long body variants
• Motor operated with Tianjin Ertong QB/QZ type electric actuator (380V/220V AC)
• Suitable for air, water, sewage, steam, gas, oil, and corrosive media
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Product Details
The D942 electric double eccentric butterfly valve — a high-performance butterfly valve (HPBV) with a motor actuator — automates large-bore lines from DN80 to DN1600. The double-offset cam lifts the disc clean of the seat on opening, cutting friction and motor torque, while six selectable seat materials cover everything from cryogenic PTFE (−268°C) to silicone (250°C). PN6/10/16, SCADA-ready.
- Motor-operated double eccentric (double offset) flanged butterfly valve, QB on-off / QZ modulating
- DN80–DN1600 (nominal to DN2000), PN6/PN10/PN16, short & long body variants
- Six seat materials: CR, NBR, EPDM, PTFE, silicone, FKM (−268 to +250°C)
- 380V/220V AC, IP67 enclosure, 4–20mA control & position feedback for DCS/SCADA
- Declutchable manual handwheel standard for power-outage operation
- Seat replaceable on-site without removing the body from the line
Product Overview
The D942 pairs Gaoshan’s double eccentric flanged body with a Tianjin Ertong QB/QZ electric actuator for remote and automated service. The double-offset geometry means the disc contacts the seat only at final closure, so friction, seat wear and torque are far lower than a centerline butterfly — the reason it is the default electric valve on large water, sewage and process mains.
Six field-selectable seat materials give the widest media and temperature range of the series, and the short/long body face-to-face options let it replace existing gate or globe valves (long body) or fit compact new runs (short body). Built to GB/T 12238 with RF flanges to GB/T 17241.
Technical Specifications
| Parameter | Specification |
|---|---|
| Nominal Diameter (DN) | 80 – 1600 mm (nominal range 50 – 2000 mm) |
| Nominal Pressure (PN) | 0.6 / 1.0 / 1.6 MPa |
| Design Standard | GB/T 12238 |
| Face-to-Face | GB/T 12221 (short & long body) |
| Flange Standard | GB/T 17241 (RF raised face) |
| Disc Design | Double eccentric (double-offset) cam-lift |
| Operation Type | Electric motor operated (QB or QZ type actuator) |
| Power Supply | 380 V AC 3-phase / 220 V AC 1-phase (50/60 Hz) |
| Enclosure Protection | IP67 weatherproof |
| Control Mode | On-off (QB type) or modulating (QZ type) |
| Applicable Media | Air, water, sewage, steam, gas, oil, and corrosive media |
Pressure Test Ratings
| Pressure Class | Body Strength (MPa) | Seat Seal (MPa) | Air Seal (MPa) |
|---|---|---|---|
| PN6 (0.6 MPa) | 0.90 | 0.68 | 0.60 |
| PN10 (1.0 MPa) | 1.50 | 1.10 | 0.60 |
| PN16 (1.6 MPa) | 2.40 | 1.76 | 0.60 |
D942 vs D342 & D642 — Same Body, Three Actuators
| Feature | D342 (Worm Gear) | D642 (Pneumatic) | D942 (Electric) |
|---|---|---|---|
| Actuator | Worm gear handwheel | Pneumatic rack & pinion | QB/QZ electric motor |
| Power Source | Manual | Compressed air 0.4–0.7 MPa | 380 V / 220 V AC |
| Max Size | DN2000 | DN500 | DN1600 |
| Control Mode | Manual (local) | On-off / modulating | On-off / modulating |
| Remote Control | No | Yes (solenoid) | Yes (DCS / SCADA) |
| Best For | Unpowered sites, large bore | Fast cycling, hazardous area | SCADA, remote automation |
The three share the same double eccentric body, seats and pressure classes; only the drive differs. See D342 (gear) and D642 (pneumatic).
Seal Material Selection & Temperature Range
| Material | Code | Min Temp | Max Temp | Working Temp | Best For |
|---|---|---|---|---|---|
| Chloroprene (CR) | X | −40 °C | 82 °C | ≤65 °C | General water, mild chemicals, weather resistant |
| Nitrile (NBR) | J | −40 °C | 93 °C | ≤80 °C | Oil, fuel, gas, hydrocarbons |
| EPDM (YBX) | YBX | −40 °C | 150 °C | ≤120 °C | Hot water, steam, polar solvents, HVAC |
| PTFE (F) | F | −268 °C | 232 °C | ≤200 °C | Corrosive chemicals, acids, cryogenic service |
| Silicone (GX) | GX | −70 °C | 250 °C | ≤200 °C | Food-grade, high-temp air, pharmaceutical |
| Fluoroelastomer (FKM) | FJ | −23 °C | 204 °C | ≤180 °C | Aggressive chemicals, high-temp oils, acids |
Materials of Main Parts
| Part | Material Options |
|---|---|
| Body | Ductile iron, cast carbon steel, alloy steel, stainless steel |
| Disc | Gray cast iron, ductile iron, cast carbon steel, stainless steel & special materials |
| Seat / Seal Ring | Various rubber compounds, PTFE (6 options — see table below) |
| Stem | 2Cr13 martensitic stainless steel, stainless steel |
| Packing | O-ring, flexible graphite |
| Electric Actuator | Tianjin Ertong QB (on-off) or QZ (modulating) type |
Electric Actuator Specifications
| Parameter | Specification |
|---|---|
| Actuator Series | QB (on-off) / QZ (modulating) |
| Power Supply | 380 V AC 3-phase 50 Hz (standard); 220 V AC 1-phase 50 Hz (optional) |
| Enclosure Rating | IP67 dust-tight & water immersion proof |
| Control Signal (QZ) | 4–20 mA DC input / output |
| Position Feedback | Potentiometer or 4–20 mA transmitter (optional) |
| Limit Switches | 2 × open + 2 × close torque/position switches (standard) |
| Manual Override | Declutchable handwheel (standard) |
| Optional Accessories | Heater (cold climate), position transmitter, local indicator, extra limit switches |
Dimensions & Weights
| DN (mm/in) | L Short (mm) | L Long (mm) | H1 (mm) | H (mm) | L1 (mm) | L2 (mm) | L3 (mm) | L4 (mm) |
|---|---|---|---|---|---|---|---|---|
| 80 / 3″ | 114 | 180 | 102 | 540 | 122 | 185 | 103 | 297 |
| 100 / 4″ | 127 | 190 | 112 | 558 | 122 | 185 | 103 | 297 |
| 125 / 5″ | 140 | 200 | 128 | 610 | 122 | 185 | 103 | 297 |
| 150 / 6″ | 140 | 210 | 145 | 730 | 122 | 185 | 103 | 297 |
| 200 / 8″ | 152 | 230 | 185 | 825 | 122 | 185 | 103 | 297 |
| 250 / 10″ | 165 | 250 | 220 | 895 | 122 | 185 | 103 | 297 |
| 300 / 12″ | 178 | 270 | 250 | 960 | 155 | 290 | 110 | 390 |
| 350 / 14″ | 190 | 290 | 280 | 1020 | 155 | 290 | 110 | 390 |
| 400 / 16″ | 216 | 310 | 316 | 1125 | 155 | 290 | 110 | 390 |
| 450 / 18″ | 222 | 330 | 344 | 1180 | 155 | 290 | 110 | 390 |
| 500 / 20″ | 229 | 350 | 370 | 1265 | 155 | 290 | 110 | 390 |
| 600 / 24″ | 267 | 390 | 440 | 1465 | 155 | 290 | 110 | 390 |
| 700 / 28″ | 292 | 430 | 505 | 1560 | 155 | 290 | 110 | 390 |
| 800 / 32″ | 318 | 470 | 570 | 1635 | 248 | 600 | 293 | 487 |
| 900 / 36″ | 330 | 510 | 630 | 1765 | 248 | 600 | 293 | 487 |
| 1000 / 40″ | 410 | 550 | 690 | 1890 | 248 | 600 | 293 | 487 |
| 1200 / 48″ | 470 | 630 | 820 | 2255 | 248 | 600 | 293 | 487 |
| 1400 / 56″ | 530 | 710 | 950 | 2495 | 368 | 655 | 368 | 591 |
| 1600 / 64″ | 600 | 790 | 1100 | 2880 | 368 | 655 | 368 | 591 |
Short & long body L shown; H extendable on request. Actuator-dependent dimensions L1–L4 based on QB/QZ. Certified drawings issued with the quotation.
Butterfly Family — Which Type to Specify
| Type | Models | Seat | Strength | Best For |
|---|---|---|---|---|
| Centerline wafer | D71X/D371X/D671X/D971X | Rubber (EPDM/NBR) | Lightest, lowest cost, PN10/16, to 135C | Water, HVAC, general |
| Double eccentric (HPBV) | D342/D642/D942 | Rubber / PTFE | Large bore to DN2000, low torque | Water, large mains |
| Triple offset (metal seat) | D343H/D363H | Laminated metal | High temp to 425C, high pressure | Steam, oil, high temp |
Structure Drawing
Design, Testing and Reference Standards
- Design GB/T 12238; face-to-face GB/T 12221 (short & long); flanges GB/T 17241 RF; testing GB/T 13927.
- Also referenced to EN 593 / API 609 and actuator mounting ISO 5211 on request.
- Material certificates to EN 10204 3.1 supplied with delivery.
Installation & Maintenance
- Check actuator supply: confirm 380/220V and control signal (on-off vs 4-20mA) before wiring.
- Leave swing/declutch clearance: keep room for the handwheel and actuator cover.
- Do not over-torque flange bolts: cross-tighten evenly to avoid distorting the rubber seat.
- Replace seat in line: the seat ring is serviceable without removing the body, cutting downtime.
- Exercise periodically: cycle the valve on a schedule so the seat and actuator stay free.
Application Fields
The D942 is specified for automated control on large-diameter water and sewage mains; pump stations and intake/discharge lines; HVAC and district heating; power plant circulating water; industrial process and irrigation; remote unmanned (SCADA) stations.
What We Need to Quote Your D942 Valves
- Size and pressure: DN80–DN1600, PN6/10/16; short or long body.
- Medium and temperature: sets the seat material (6 options).
- Actuator: QB on-off or QZ modulating; supply voltage; 4–20mA; feedback.
- Body material: ductile iron / cast steel / stainless.
- Documentation: EN 10204 3.1 on request.
Frequently Asked Questions
What does double eccentric (high performance) mean?
Two offsets move the disc axis off the stem and seat axes, so the disc lifts off the seat as soon as it opens – far less friction, wear and torque than a centerline butterfly. That is why it is called a high performance butterfly valve (HPBV).
Electric vs pneumatic vs gear – which actuator?
Electric (D942) for SCADA/DCS remote automation and precise positioning; pneumatic (D642) for fast cycling and hazardous areas; gear (D342) for unpowered sites and the largest bores. The body is the same.
Which seat material for my medium?
NBR for oil/fuel/gas, EPDM for hot water/steam/HVAC, PTFE for acids/cryogenic, silicone for food-grade/high-temp air, FKM for aggressive chemicals, CR for general water. The selection table maps each with temperature limits.
Can it replace an existing gate or globe valve?
Yes – the long-body face-to-face matches many gate/globe valves for direct replacement; the short body suits compact new installs. Confirm the existing face-to-face and we will match.
What if power fails?
A declutchable manual handwheel is standard on the QB/QZ actuators, so the valve can be operated by hand during an outage.
Is the seat replaceable in line?
Yes, the seat ring can be replaced without removing the body from the pipeline, which cuts downtime on large-bore installations.
Get a Quote & Technical Support
Gaoshan Valve has manufactured industrial valves since 1975 and holds ISO 9001/14001/45001, CE (EU PED) and API 6D certification, an approved supplier to Sinopec, CNPC and State Grid, exporting to more than 30 countries. Reply within 24 hours.
