D71X Wafer Butterfly Valve (DN40–DN200) | PN10/PN16
The D71X Wafer Butterfly Valve is available in PN10 and PN16 models with a compact wafer face-to-face design. It is offered in gray cast iron, ductile iron, or WCB cast steel bodies, with a Buna-N seat, 2Cr13 stainless steel stem, and ductile iron disc. Suitable for steam, water, petroleum, and weak acid/alkali media up to 135°C, in sizes DN40 to DN200.
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Product Details
The D71X wafer butterfly valve is a centerline, resilient seated butterfly valve operated by a manual lever — the lightest, most economical way to isolate a water, HVAC or process line between standard flanges. A full Buna-N (NBR) rubber lining gives bi-directional, zero-leakage shut-off against steam, water, petroleum, weak acids and alkalis up to 135°C, in six body variants across PN10 and PN16, DN40–DN200.
- Resilient (rubber) seated centerline design — tight bi-directional shut-off, zero leakage at rated conditions
- Manual lever operation as standard; gearbox, pneumatic or electric actuator options on the same ISO 5211 pad
- Six variants: gray cast iron / ductile iron / WCB cast steel bodies at PN10 and PN16
- Compact face-to-face length (L = 43–60 mm) fits between any standard PN10/16 flanges
- 2Cr13 stainless steel stem, ductile iron disc, self-lubricating aluminium bronze bushings
- DN40–DN200; standard sizes in stock for fast worldwide shipment
Product Overview
The D71X wafer butterfly valve is a centerline-disc, rubber-seated butterfly valve designed for installation between standard flanges without dedicated lug hardware. 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. A compact face-to-face length and a lightweight disc design reduce pipeline load and installation time, making the D71X a cost-effective resilient seated solution for HVAC, water treatment, industrial process and fire-protection systems.
As a factory-direct manufacturer since 1975, Gaoshan Valve supplies CE and API certified quality at competitive factory pricing, with standard sizes in stock for fast global shipment.
Model Designation Guide
| Model | Nominal Pressure | Body Material | Typical Application |
|---|---|---|---|
| D71X-10 | PN10 | Gray Cast Iron (HT200) | General water & HVAC service |
| D71X-10Q | PN10 | Ductile Cast Iron (QT450) | Slightly elevated mechanical duty, PN10 |
| D71X-10C | PN10 | WCB Cast Steel | Steam, petroleum, mild chemicals, PN10 |
| D71X-16 | PN16 | Gray Cast Iron (HT200) | General water & HVAC service, higher pressure |
| D71X-16Q | PN16 | Ductile Cast Iron (QT450) | Higher-duty service, PN16 |
| D71X-16C | PN16 | WCB Cast Steel | Steam, petroleum, mild chemicals, PN16 |
Key Advantages
Compact Wafer Design
Short face-to-face length (L = 43–60 mm) minimises pipeline spool length and installation space. Installs between any standard PN10/16 flanges without dedicated bolts or lugs.
Versatile Body Options
Choose gray cast iron for economy, ductile iron for improved impact resistance, or WCB cast steel for high-pressure steam and petrochemical service — all sharing the same external dimensions.
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 service life in continuous-cycle applications.
ISO 5211 Actuator Pad
Standard ISO 5211 top-flange interface allows direct mounting of manual levers, gearboxes, or pneumatic/electric actuators without adapter brackets.
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 | DN40 – DN200 | DN40 – DN200 |
| End Connection | Wafer (centerline, between-flange) | Wafer (centerline, between-flange) |
| Disc Type | Centerline disc | Centerline disc |
| Operation | Manual lever (standard); gearbox or actuator optional | Manual lever (standard); gearbox or actuator optional |
| 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 | D71X-10 / -16 | D71X-10Q / -16Q | D71X-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) — PN10 / PN16
| DN | L | H | H0 | A | B |
|---|---|---|---|---|---|
| DNDN40 | 43 | 55 | 188 | 272 | 103 |
| DNDN50 | 43 | 58 | 224 | 272 | 103 |
| DNDN65 | 46 | 82 | 235 | 272 | 103 |
| DNDN80 | 46 | 85 | 240 | 272 | 103 |
| DNDN100 | 52 | 105 | 312 | 272 | 103 |
| DNDN125 | 56 | 128 | 350 | 272 | 103 |
| DNDN150 | 56 | 138 | 380 | 318 | 103 |
| DNDN200 | 60 | 175 | 570 | 436 | 149 |
L = face-to-face length; H = valve height (lever closed); H0 = total height (lever open); A = lever length; B = valve width (body only). All values in mm. PN10 and PN16 share identical face-to-face dimensions.
Selection Guide: Wafer vs. Lug vs. Double-Flanged
| Feature | D71X (Wafer) | Lug Type | Double-Flanged |
|---|---|---|---|
| Dead-end service | ✗ No | ✓ Yes | ✓ Yes |
| Installation cost | Lowest | Medium | Highest |
| Weight / pipe load | Lightest | Medium | Heaviest |
| Pipe removal without valve removal | ✗ No | ✓ Yes | ✗ No |
| Typical use | Through-line service | End-of-line / isolation | High pressure / large bore |
Choose the wafer pattern where weight and installed cost matter and the valve sits inside a continuous line. For dead-end isolation or lines that must be opened downstream of the valve, see the lug and double-flanged patterns in the butterfly valve series.
Butterfly Valve Family at a Glance
| Type | Models | Seat | Characteristics | Typical Service |
|---|---|---|---|---|
| Centerline wafer | D71X (this page) / D371X / D671X / D971X | 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 D71X 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.
- Stem Torque Verification — full open/close cycle under differential pressure to confirm lever and stem adequacy.
- 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: D71X valves can be installed in any pipe orientation (horizontal, vertical or inclined). Confirm the lever has adequate swing clearance before finalising position.
- 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.
- Flow direction: No flow-direction restriction for full on/off service. For throttling applications, confirm acceptable disc stability with our applications team.
- Rubber seat inspection: Inspect the NBR seat annually or after prolonged steam service. Replace if cracking, swelling or permanent deformation is observed.
- Stem packing: The stem uses O-ring sealing; no packing adjustment is required. Replace O-rings if stem leakage is detected during service.
- Actuator upgrade: The ISO 5211 top pad accepts standard pneumatic or electric actuators. Consult Gaoshan Valve for actuator sizing and bracket selection.
International Standards & Certification
The D71X 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 D71X 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 and CNPC, exporting to more than 20 countries.
- 50-year factory — manufacturing industrial valves since 1975, 400+ employees, 120,000 m² facility
- Certified quality — CE (EU PED), API 6D, ISO 9001/14001/45001
- Trusted by majors — approved supplier to Sinopec, CNPC and projects in 20+ countries
- 100% tested — every valve passes shell test and seat leakage test before shipment
- Fast delivery — standard sizes DN40–DN200 in stock, ready to ship worldwide
Frequently Asked Questions
What is the minimum order quantity (MOQ)?
No strict MOQ. Trial orders from 1 piece are accepted for standard sizes (DN40–DN200); bulk pricing applies from 50+ units.
How long does delivery take?
Standard cast iron and ductile iron sizes are in stock and ship within 3–7 working days. WCB cast steel and custom configurations take 15–25 working days. Worldwide shipping by sea and air freight.
Do you provide inspection reports and certifications?
Yes. Every shipment includes a factory inspection report with shell and seat leakage test results. CE, API 6D and ISO 9001 certificates are available, and third-party inspection (SGS, BV, TUV) can be arranged.
What payment terms do you accept?
T/T (30% deposit, 70% before shipment) and L/C at sight. For trial orders, Western Union and PayPal are accepted.
Can you customize flange drilling to ANSI or DIN?
Yes. The standard drilling is GB/T 17241. ANSI B16.5 Class 150, DIN EN 1092 and JIS drilling are available on request at no extra cost for bulk orders.
Which seat materials can I specify?
NBR (Buna-N) is standard and suits water, steam to 135°C, petroleum and weak acids/alkalis. EPDM or PTFE-lined seats are available on request — tell us the medium and temperature and we will recommend the right seat.
Ordering Information
| Item | Specify When Ordering |
|---|---|
| Model | D71X-10 / 10Q / 10C / 16 / 16Q / 16C |
| Nominal Size | DN40 / DN50 / DN65 / DN80 / DN100 / DN125 / DN150 / DN200 |
| Flange Drilling Standard | GB/T 17241 (standard); ANSI / DIN on request |
| Operation Type | Manual lever (standard); gearbox; pneumatic or electric actuator |
| Seat Material | NBR (standard); EPDM / PTFE-lined on request |
| Disc Coating | Standard ductile iron; nickel-plated or SS disc on request |
Related Butterfly Valves
D371X Gear-Operated Wafer Butterfly Valve — the same wafer body with a worm gear for larger bores (DN50–DN500). D671X Pneumatic Wafer Butterfly Valve and D971X Electric Wafer Butterfly Valve — pneumatic and electric actuated versions. D342 Double Eccentric Butterfly Valve — double eccentric pattern for larger mains.
Get a Quote & Technical Support
Gaoshan Valve supplies D71X wafer butterfly valves with certified inspection reports. Fast delivery for standard sizes; custom sizes and actuated assemblies available on request. Send the line data and our engineering team replies within 24 hours.
