D971X Electric Wafer Butterfly Valve

The D971X electric actuated wafer butterfly valve pairs our centerline, rubber seated wafer butterfly valve body with a compact electric actuator for remote on-off control — and 4–20 mA modulating control on request — from DN50 to DN500. Standard 220 V AC supply (380 V AC or 24 V DC on request), open/close feedback for PLC / DCS / SCADA, a declutchable manual override handwheel, and the same Buna-N (NBR) bi-directional seal as the manual D71X — PN10 / PN16, up to 135°C.

• Electric actuated centerline wafer design — on/off (standard) or modulating 4–20 mA control
• DN50–DN500, six variants: gray cast iron / ductile iron / WCB cast steel bodies at PN10 and PN16
• Power supply 220 V AC (standard), 380 V AC or 24 V DC; open/close feedback for PLC / DCS / SCADA
• Declutchable manual override handwheel for emergency operation during power loss
• ISO 5211 actuator mounting pad; explosion-proof Ex d IIBT4 version on request
• Water, steam, petroleum, weak acid and alkali service up to 135°C; zero leakage per GB/T 13927

Product Overview

The D971X electric wafer butterfly valve combines the proven centerline-disc design of the D71X family with a compact electric actuator, enabling remote on/off control, PLC integration, and automated process sequencing. Six standard variants cover PN10 and PN16 pressure classes with three body material options — gray cast iron (standard), ductile cast iron (intermediate duty), and WCB cast steel (high-pressure service). The Buna-N (NBR) elastomer lining provides reliable bi-directional shutoff against steam, water, petroleum products, weak acids, and alkalis. The electric actuator accepts standard 220 V / 380 V / 24 V DC supply voltages and integrates seamlessly with building management systems, water treatment SCADA, and industrial automation networks. With a compact overall height and a lightweight disc design, the D971X is ideal for remote-operated water distribution, fire protection, HVAC, and process isolation applications.

As a factory-direct manufacturer since 1975, Gaoshan Valve supplies CE-marked, API 6D certified quality at competitive factory pricing, with standard configurations ready for fast global shipment.

Model Designation Guide

Model	Nominal Pressure	Body Material	Typical Application
D971X-10	PN10	Gray Cast Iron (HT200)	Water distribution, HVAC remote control
D971X-10Q	PN10	Ductile Cast Iron (QT450)	Elevated mechanical duty, PN10 automation
D971X-10C	PN10	WCB Cast Steel	Steam, petroleum, mild chemical remote control
D971X-16	PN16	Gray Cast Iron (HT200)	Higher-pressure water automation, PN16
D971X-16Q	PN16	Ductile Cast Iron (QT450)	Higher-duty automated service, PN16
D971X-16C	PN16	WCB Cast Steel	Steam, petroleum, chemicals, PN16 automation

Key Advantages

Remote On/Off Control

Electric actuator accepts standard 220 V / 380 V / 24 V DC supply and provides open/close feedback signals for PLC, DCS, or SCADA integration without additional positioners.

Compact Vertical Profile

The electric actuator reduces overall height compared to worm-gear models, making the D971X suitable for low-clearance installations in valve pits and equipment skids.

Full NBR Elastomer Lining

The Buna-N rubber seat ring and O-ring provide tight bi-directional shutoff against water, steam (≤135 °C), petroleum, weak acids, and alkalis, with zero leakage at rated conditions.

2Cr13 Stainless Steel Stem

The martensitic stainless steel stem combines corrosion resistance with the high torsional strength needed to operate large-bore discs under differential pressure.

Aluminium Bronze Axis Guide

Self-lubricating aluminium bronze bushings reduce stem friction and wear, lowering operating torque and extending actuator service life in continuous-cycle applications.

Integrated Over-Torque Protection

The electric actuator includes built-in torque limiters and thermal overload protection, preventing disc and seat damage during obstruction or end-of-travel conditions.

Electric Actuator Selection

Size the electric package from three linked decisions: the control mode (on-off or modulating), the power supply on site, and what must happen on power loss. Every D971X ships with certified inspection reports and actuator documentation, including wiring diagrams.

On-Off vs. Modulating Control

• On/off (standard): the actuator drives the disc fully open or fully closed and returns open/close feedback signals for PLC, DCS or SCADA integration — no additional positioner needed.
• Modulating (on request): a 4–20 mA control signal positions the disc anywhere in the travel for throttling duty.

Power Supply Options

• 220 V AC: standard single-phase supply, the default for most water and HVAC projects.
• 380 V AC: three-phase supply for plants with 380 V distribution.
• 24 V DC: low-voltage DC supply on request for control-cabinet-powered installations.
• Specify the voltage when ordering; verify voltage and phase before energising and install an external isolator switch within sight of the valve.

Fail Position, Override & Protection

• Fail position: on power loss the actuator holds its last position (fail-last) as standard; use the declutchable manual handwheel for emergency operation.
• Over-torque protection: built-in torque limiters and thermal overload protection prevent disc and seat damage during obstruction or end-of-travel conditions.
• Hazardous areas: explosion-proof Ex d IIBT4 actuator version available on request.
• Mounting: the actuator bolts to an ISO 5211 top pad machined on the valve body, keeping the D971X interchangeable with other actuator brands.

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	≤ 135 °C
Size Range	DN50 – DN500	DN50 – DN500
End Connection	Wafer (centerline, between-flange)	Wafer (centerline, between-flange)
Disc Type	Centerline disc	Centerline disc
Operation	Electric actuator (standard); manual override handwheel included	Electric actuator (standard); manual override handwheel included
Power Supply	220 V AC / 380 V AC / 24 V DC (specify when ordering)	220 V AC / 380 V AC / 24 V DC (specify when ordering)
Applicable Medium	Steam, water, petroleum, weak acid, alkali	Steam, water, petroleum, weak acid, alkali
Design Standard	GB/T 13927 (pressure test); GB/T 12238 (face-to-face)	GB/T 13927 (pressure test); GB/T 12238 (face-to-face)

Applicable Media

• Steam (≤135 °C)
• Water
• Seawater
• Petroleum
• Fuel Oil
• Weak Acid
• Alkali Solutions
• HVAC Hot/Chilled Water
• Fire Protection Water
• Sewage / Wastewater

Materials of Construction

Component	D971X-10 / -16	D971X-10Q / -16Q	D971X-10C / -16C
Body	Gray Cast Iron (HT200)	Ductile Cast Iron (QT450-10)	WCB Cast Steel
Seat Ring	Buna-N Rubber (NBR)	Buna-N Rubber (NBR)	Buna-N Rubber (NBR)
Stem / Worm	2Cr13 Stainless Steel	2Cr13 Stainless Steel	2Cr13 Stainless Steel
Disc	Ductile Cast Iron (QT450-10)	Ductile Cast Iron (QT450-10)	Ductile Cast Iron (QT450-10)
Axis Guide / Bushing	Aluminium Bronze	Aluminium Bronze	Aluminium Bronze
O-Ring Sealing	Buna-N Rubber (NBR)	Buna-N Rubber (NBR)	Buna-N Rubber (NBR)

Principal Dimensions (mm) & Weight (kg) — PN10 / PN16

DN	H1	H2	H3	L	L1	Wt.
DNDN50	68	118	255	43	126	20
DNDN65	82	140	255	46	126	21
DNDN80	85	150	255	46	126	23
DNDN100	105	180	255	52	126	26
DNDN125	128	200	255	56	126	27
DNDN150	138	210	255	56	126	31
DNDN200	175	245	255	60	126	39
DNDN250	205	280	255	68	126	55
DNDN300	245	320	255	78	126	89
DNDN350	265	340	255	78	126	92
DNDN400	295	380	302	102	175	171
DNDN450	326	420	302	114	175	189
DNDN500	345	460	302	127	175	219

H1 = centerline to top of actuator; H2 = centerline to handwheel; H3 = actuator offset; L = face-to-face length; L1 = actuator length. All values in mm. PN10 and PN16 share identical face-to-face dimensions. Weights include valve body, disc, and fully assembled electric actuator.

Drive Options: Lever vs. Gear vs. Pneumatic vs. Electric

Feature	D71X Lever	D371X Gear	D671X Pneumatic	D971X Electric
Operation	Manual Lever	Worm Gear	Pneumatic	Electric Motor
Size Range	DN40–DN200	DN50–DN500	DN50–DN500	DN50–DN500
Remote Control	✗ None	✗ None	✓ Air signal	✓ PLC / DCS / SCADA
Utility Required	None	None	Compressed air	Electricity
Fail Position	N/A	N/A	Fail-close / fail-open	Fail-last (standard)
Best For	Infrequent manual	Frequent manual, large bore	High-speed, ESD safety	Remote automation

Rule of thumb: the lever-operated D71X for infrequent manual isolation, the gear-operated D371X for frequent manual cycling of larger bores, the pneumatic D671X where speed and a defined fail-safe position matter (compressed air available), and the D971X for remote automation on electric power — PLC / DCS / SCADA control with no air system required.

Butterfly Valve Family at a Glance

Type	Models	Seat	Characteristics	Typical Service
Centerline wafer	D71X / D371X / D671X / D971X (this page)	Rubber (NBR / EPDM)	Lightest & most economical; PN10 / PN16; ≤135°C	Water, HVAC, general service
Double eccentric (high performance)	D342 / D642 / D942	Rubber / PTFE	Large bores, PN6–PN16, low operating torque	Water mains, large pipelines
Triple offset (metal seated)	D343H / D363H	Laminated metal	High temperature & high pressure service	Steam, hot oil, petroleum

Browse the whole butterfly valve series or compare drive options for the same wafer body: D71X (manual lever), D371X (worm gear), D671X (pneumatic) and D971X (electric).

Structure Drawing

Quality Assurance & Testing

Every D971X electric butterfly valve undergoes the following factory acceptance tests before shipment:

• 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 required per GB/T 13927 Class VI.
• Electric Actuator Function Test — full open/close cycle with torque and limit-switch verification under load.
• Insulation Resistance Test — electrical integrity of motor windings and terminal box checked per manufacturer specification.
• Dimensional Inspection — face-to-face, flange bolt-circle, and bore dimensions checked against GB/T 12238.
• Visual & NDT — casting surfaces inspected; critical welds (cast steel models) subject to dye-penetrant examination.

Installation & Maintenance Notes

• Orientation: D971X valves can be installed in any pipe orientation. Ensure adequate clearance above the actuator for cable entry and manual override handwheel access.
• Electrical connection: Connect power supply via the actuator terminal box per the wiring diagram. Verify voltage and phase before energising. Install an external isolator switch within sight of the valve.
• Flange bolts: Use through-bolts to clamp both pipe flanges together through the wafer body. Tighten in a cross pattern.
• Manual override: The electric actuator includes a declutchable manual handwheel for emergency operation during power loss.
• Rubber seat inspection: Inspect the NBR seat annually or after prolonged steam service. Replace if cracking, swelling, or permanent deformation is observed.
• Actuator maintenance: Check actuator lubricant and torque calibration every 12 months or 1,000 cycles, whichever comes first.

International Standards & Certification

The D971X family is manufactured and tested to Chinese national standards with international equivalents available on request: face-to-face dimensions to GB/T 12238, pressure testing to GB/T 13927, and flange drilling to GB/T 17241 as standard. On request we quote and certify to EN 593 or API 609 design equivalents, and the ISO 5211 actuator mounting pad is machined as standard.

• CE-marked (EU PED) and holding API 6D plus ISO 9001 / ISO 14001 / ISO 45001 management system certification
• China pressure-pipeline valve manufacturing license held by the factory
• Every valve passes shell and seat leakage tests before shipment; factory inspection report included
• EN 593 / API 609 conformance documentation on request

Why Buy D971X from Gaoshan Valve

Gaoshan Valve has manufactured industrial valves since 1975 and is CE-marked with API 6D and ISO 9001/14001/45001 certification. We are an approved supplier to Sinopec, CNPC and State Grid, exporting to more than 30 countries.

• 50-year factory — manufacturing industrial valves since 1975
• Certified quality — CE (EU PED), API 6D, ISO 9001/14001/45001, China pressure-pipeline valve manufacturing license
• Trusted by majors — approved supplier to Sinopec, CNPC and State Grid; exports to 30+ countries
• 100% tested — every valve passes shell test, seat leakage test, actuator function and insulation resistance tests before shipment
• Automation-ready — explosion-proof and modulating configurations available on request

Frequently Asked Questions

Ordering Information

Item	Specify When Ordering
Model	D971X-10 / 10Q / 10C / 16 / 16Q / 16C
Nominal Size	DN50 – DN500
Power Supply	220 V AC (standard); 380 V AC; 24 V DC (on request)
Control Signal	On/off (standard); modulating (4–20 mA) on request
Explosion-Proof Rating	Standard (non-Ex); Ex d IIBT4 on request
Flange Drilling Standard	GB/T 17241 (standard); ANSI / DIN on request
Seat Material	NBR (standard); EPDM / PTFE-lined on request
Disc Coating	Standard ductile iron; nickel-plated or SS disc on request

Related Butterfly Valves

D671X Pneumatic Wafer Butterfly Valve — the same wafer body on compressed air with fail-close / fail-open spring return. D71X Wafer Butterfly Valve — the manual lever version for small bores. D371X Gear-Operated Wafer Butterfly Valve — worm gear operation for larger bores. D342 Double Eccentric Butterfly Valve — move up to double eccentric duty for larger mains.

Get a Quote & Technical Support

Gaoshan Valve supplies D971X electric wafer butterfly valves with certified inspection reports and actuator documentation. Fast delivery for standard sizes; explosion-proof and modulating configurations available on request. Contact our team for pricing, wiring diagrams, and application guidance — reply within 24 hours.

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