D363H Triple Eccentric Hard-Seal Butterfly Valve
Triple offset (triple eccentric) geometry: zero seat friction, bidirectional tight shut-off
Laminated stainless + graphite metal seat disc, continuous service to 425°C
Butt-weld end connection; body in WCB cast steel or stainless (CF8/CF8M), PN2.5–PN40
DN80–DN1800; worm gear standard, pneumatic (D663H) or electric (D963H) on request
Low operating torque — disc contacts seat only in the final degrees of closure
Suitable for steam, high-temperature oil, natural gas, water and mild acids
Contact Us for Pricing
Interested in this product? Contact us now for detailed pricing and product information.
Product Details
The D363H triple offset butterfly valve — the pattern international specs call a triple eccentric or metal-seated butterfly valve — is the butterfly valve for service where an elastomer seat fails: steam and hot oil to 425°C, high pressure to PN40, and corrosive or abrasive media. Three eccentricities lift the disc clean of the seat through the whole stroke, so sealing is friction-free and bidirectional, in a butt-weld body from DN80 to DN1800.
- Triple offset (triple eccentric) geometry: zero seat friction, bidirectional tight shut-off
- Laminated stainless + graphite metal seat disc, continuous service to 425°C
- Butt-weld end connection; body in WCB cast steel or stainless (CF8/CF8M), PN2.5–PN40
- DN80–DN1800; worm gear standard, pneumatic (D663H) or electric (D963H) on request
- Low operating torque — disc contacts seat only in the final degrees of closure
- Suitable for steam, high-temperature oil, natural gas, water and mild acids
Product Overview
The D363H is the butt-weld end version of Gaoshan’s triple-offset hard-seal butterfly family, for high-temperature and high-pressure lines where welded piping is preferred and a soft seat would degrade. The triple-offset geometry — offset stem axis, offset disc axis, and a conical sealing angle — means the disc only contacts the seat in the last few degrees of closure, eliminating the rubbing that wears a conventional butterfly seat. The result is bidirectional tight shut-off that holds over the valve’s life, with low operating torque.
The sealing face is a laminated disc of stainless steel and flexible graphite, which flexes slightly to conform to the seat and tolerates temperature cycling that would crack a solid metal or elastomer seat. Body and disc are WCB cast steel as standard, with stainless and duplex options; the seat laminate can be all-stainless for high temperature or PTFE for chemical service.
Where a resilient-seated butterfly is the economical choice for water and HVAC, and a double-eccentric valve covers mid-range duty, the triple offset is the answer once temperature, pressure or abrasion rule out an elastomer. See the comparison below and the butterfly valve series.
Model Designation Guide
| Model Code | Pressure | Size Range | End Connection | Drive |
|---|---|---|---|---|
| D363H-10C / 16C | PN10 / PN16 | DN80 – DN3200 | Butt-Weld (GB/T 12221) | Worm gear handwheel |
| D363H-25C / 40C | PN25 / PN40 | DN80 – DN3200 | Butt-Weld (GB/T 12221) | Worm gear handwheel |
| D663H (Pneumatic) | PN10 – PN40 | DN80 – DN3200 | Butt-Weld | Pneumatic actuator |
| D963H (Electric) | PN10 – PN40 | DN80 – DN3200 | Butt-Weld | Electric actuator 380V/220V |
Why Triple Offset Seals Better
Three Eccentricities, Zero Friction
Two offsets move the disc axis off the stem and seat axes; the third makes the sealing surfaces conical. The disc therefore lifts clear of the seat as soon as it opens and only touches it at the very end of closure, so there is no rubbing wear across the stroke and torque stays low.
Bidirectional, Pressure-Assisted Shut-Off
The conical metal-to-metal seal tightens as differential pressure rises, in either direction, giving zero-leakage class performance both ways — important where a line can see reverse flow.
Laminated Seat Disc for Thermal Cycling
The stainless + graphite laminate flexes to conform to the seat and absorbs thermal cycling that cracks a solid metal seat, which is why the valve holds its seal on steam and hot oil that cycle daily.
Metal Seat Where Elastomers Fail
At 425°C and in abrasive or hydrocarbon service an EPDM or PTFE seat ages quickly; the metal laminate does not. That is the whole reason to pay for a triple offset.
Materials of Construction
| Component | Standard | Optional |
|---|---|---|
| Body (阀体) | Cast Steel (WCB) | Stainless Steel (CF8, CF8M) |
| Disc (蝶板) | Cast Steel | Stainless Steel; Duplex SS |
| Shaft (阀杆) | Cast Steel | Stainless Steel (316) |
| Seat Ring (阀座) | Carbon Steel | Stainless Steel; PTFE-lined; Rubber-lined |
| Laminated Disc Seal | Stainless steel + Flexible Graphite laminate | All-SS laminate (high-temp); PTFE laminate (chemical) |
| Stem Packing | Flexible Graphite | PTFE; PTFE + Graphite composite |
Design & Inspection Standards
| Design / Manufacturing | End Connection | Face-to-Face Length | Pressure Test & Inspection |
|---|---|---|---|
| JB/T 8527 | GB/T 12221 (Butt-Weld) | GB/T 12221 | GB/T 13927 |
International Standards & Certification
- Also referenced to international equivalents on request: design to API 609 / EN 593, actuator mounting to ISO 5211, testing to API 598 / ISO 5208.
- Material certificates to EN 10204 3.1 supplied with delivery; CE / PED documentation on request.
- Torque calculation and sizing support available from our engineering team for actuated versions.
Connection Dimensions (Butt-Weld)
PN10 / PN16 (1.6 MPa)
| DN | NPS | L | Dn | H0 | H | A | B | G | |
|---|---|---|---|---|---|---|---|---|---|
| 80 | 3″ | 188 | 78 | 91 | 85 | 225 | 50 | 144 | 180 |
| 100 | 4″ | 190 | 106 | 117 | 100 | 245 | 50 | 144 | 180 |
| 150 | 6″ | 210 | 159 | 172 | 180 | 310 | 63 | 200 | 300 |
| 200 | 8″ | 230 | 206 | 223 | 205 | 360 | 63 | 200 | 300 |
| 250 | 10″ | 270 | 259 | 278 | 235 | 395 | 80 | 230 | 350 |
| 300 | 12″ | 270 | 308 | 329 | 265 | 425 | 80 | 230 | 350 |
| 400 | 16″ | 310 | 387 | 413 | 335 | 520 | 125 | 260 | 400 |
| 500 | 20″ | 350 | 488 | 516 | 405 | 615 | 125 | 370 | 400 |
| 600 | 24″ | 350 | 591 | 629 | 465 | 665 | 160 | 398 | 500 |
| 700 | 28″ | 430 | 693 | 721 | 540 | 760 | 200 | 418 | 600 |
| 800 | 32″ | 470 | 793 | 825 | 625 | 865 | 200 | 418 | 600 |
| 1000 | 40″ | 550 | 996 | 1029 | 755 | 1030 | 263 | 510 | 700 |
| 1200 | 48″ | 630 | 1194 | 1235 | 880 | 1165 | 333 | 550 | 800 |
| 1400 | 56″ | 710 | 1394 | 1440 | 1010 | 1335 | 333 | 550 | 800 |
| 1600 | 64″ | 790 | 1594 | 1640 | 1125 | 1470 | 374 | 590 | 900 |
| 1800 | 72″ | 870 | 1794 | 1840 | 1240 | 1585 | 374 | 590 | 900 |
PN25 / PN40 (4.0 MPa)
| DN | NPS | L | Dn | H0 | H | A | B | G | |
|---|---|---|---|---|---|---|---|---|---|
| 80 | 4″ | 180 | 78 | 91 | 85 | 225 | 50 | 144 | 180 |
| 100 | 4″ | 190 | 102 | 117 | 100 | 245 | 56 | 144 | 180 |
| 150 | 6″ | 210 | 154 | 172 | 180 | 310 | 80 | 230 | 350 |
| 200 | 8″ | 230 | 203 | 223 | 205 | 360 | 80 | 230 | 350 |
| 250 | 10″ | 270 | 255 | 278 | 235 | 395 | 80 | 230 | 350 |
| 300 | 12″ | 270 | 305 | 329 | 265 | 425 | 80 | 230 | 350 |
| 400 | 16″ | 310 | 387 | 413 | 340 | 620 | 160 | 398 | 500 |
| 500 | 20″ | 350 | 488 | 516 | 405 | 615 | 125 | 370 | 400 |
| 600 | 24″ | 350 | 591 | 619 | 500 | 740 | 200 | 418 | 600 |
| 700 | 28″ | 430 | 686 | 721 | 540 | 760 | 200 | 418 | 600 |
| 800 | 32″ | 470 | 793 | 825 | 625 | 865 | 200 | 418 | 600 |
| 900 | 36″ | 510 | 889 | 927 | 890 | 1010 | 333 | 550 | 800 |
| 1000 | 40″ | 550 | 996 | 1029 | 755 | 1040 | 333 | 550 | 800 |
| 1200 | 48″ | 630 | 1194 | 1235 | 880 | 1165 | 333 | 550 | 800 |
| 1400 | 56″ | 710 | 1394 | 1440 | 1010 | 1355 | 374 | 590 | 900 |
| 1600 | 64″ | 790 | 1594 | 1640 | 1125 | 1470 | 374 | 590 | 900 |
Unit: mm. Dn = pipe bore, H0 = face-to-face, H = height, A/B = envelope, G = gear handwheel diameter. Sizes to DN3200 on request; certified drawings issued with the quotation.
Triple Offset, Double Eccentric or Resilient Seat: Which Butterfly Valve
| Duty | D363H triple offset (this page) | D342 double eccentric | Resilient seated (D371X/D71X) |
|---|---|---|---|
| Max temperature | 425°C metal seat | ~150-200°C | ~80-120°C elastomer |
| Seat | Laminated metal, bidirectional | Metal or rubber | EPDM/NBR |
| Pressure | To PN40 | PN10-25 | PN10-16 |
| Best for | Steam, hot oil, gas, abrasive, high temp | Water/medium duty, large DN | Water, HVAC, economical |
| Choose it when | Elastomer would degrade | Mid-range water duty | Clean water at low temp |
Structure Drawing
Key Features & Advantages
- Zero-friction stroke extends seat life in frequent-cycling service.
- Bidirectional tight shut-off meets zero-leakage standard over the valve life.
- Low torque allows smaller, cheaper actuators on automated versions.
- Butt-weld body suits welded piping with no flange leak paths.
- Wide material and seat options cover steam, chemical and abrasive duty.
What We Need to Quote Your D363H Valves
- Size and pressure: DN80–DN1800, PN2.5–PN40.
- Medium and temperature: sets the seat laminate and body material.
- End connection: butt-weld as standard; confirm pipe schedule for the weld end.
- Drive: worm gear standard; pneumatic (D663H) or electric (D963H) with voltage on request.
- Body / seat options: WCB or stainless; all-SS or PTFE laminate as required.
- Documentation: EN 10204 3.1, torque calculation, CE/PED on request.
Send the line data and we will return sizing, torque and a tailored quotation within 24 hours. Drawings are in the download center and qualifications on the certifications page.
Frequently Asked Questions
What is a triple offset (triple eccentric) butterfly valve?
It is a butterfly valve whose stem and seat use three geometric offsets so the disc lifts completely clear of the seat during the stroke and only contacts it at final closure. That eliminates rubbing wear, gives bidirectional metal-to-metal tight shut-off, and lets it handle high temperature and pressure that destroy elastomer-seated valves.
When do I need a triple offset instead of a normal butterfly valve?
When temperature, pressure or abrasion rule out an elastomer seat – typically steam and hot oil above about 150 degC, high pressure, or abrasive/corrosive media. For clean water and HVAC a resilient-seated butterfly is cheaper and fine; the triple offset is the high-service answer.
Is it bidirectional?
Yes. The conical metal seal is pressure-assisted in both directions, so it gives tight shut-off regardless of flow direction – useful where a line can see reverse flow.
What temperature can it handle?
Continuous service to 425 degC with the stainless + graphite laminated seat. For higher or more corrosive duty we can supply an all-stainless or PTFE laminate – send the medium and temperature.
Can it be actuated?
Yes. The low torque of the triple-offset design suits pneumatic (D663H) or electric (D963H, 380/220V) actuators, with mounting to ISO 5211. Tell us the supply and fail position and we will size the actuator.
What is the size and pressure range?
DN80 to DN1800 as standard, to DN3200 on request, across PN2.5 to PN40, in butt-weld end connection. Worm gear is standard; confirm the pipe schedule for the weld preparation.
Get a Quote & Technical Support
Gaoshan Valve has manufactured industrial valves since 1975 and holds ISO 9001/14001/45001 with CE, API 6D and PED certification, exporting to more than 30 countries. Contact our engineering team for D363H sizing, torque calculation and certification support. Reply within 24 hours.
