D363H Triple Eccentric Hard-Seal Butterfly Valve

• Gaoshan D63H bidirectional triple eccentric hard-seal butterfly valve, butt-weld end, PN2.5 to PN40, DN80–DN1800
• Laminated metal seat disc rated to 425°C; zero-friction open/close by triple-offset design
• Three eccentricities eliminate seat contact during stroke — extended service life in frequent cycling
• Butt-weld end connections; body in cast steel or stainless steel
• Suitable for steam, high-temp oil, corrosive media, natural gas — bidirectional tight shut-off

Model: D363H Series  |  Pressure: PN2.5 / PN4 / PN6 / PN10 / PN16 / PN25 / PN40  |  Connection: Butt-Weld  |  Medium: Steam, Oil, Gas, Water, Acid

Gaoshan Valve — D363H Bidirectional Triple Eccentric Hard-Seal Butterfly Valve (Butt-Weld)

Gaoshan D363H triple-offset hard-seal butterfly valve is the butt-weld version of the D43H series, designed for high-temperature and high-pressure service where soft-seat valves cannot perform. The triple-offset geometry ensures the disc lifts completely clear of the seat throughout the stroke, eliminating rubbing contact and reducing operating torque. The laminated metal disc seal withstands continuous service up to 425°C. Butt-weld end connections conform to GB/T 12221, with worm gear standard and pneumatic or electric actuator options.

Nominal Pressure
PN2.5 – PN40
Size Range
DN80 – DN1800
Design Type
Triple Eccentric
Max Temperature
Up to 425 °C
End Connection
Butt-Weld (GB/T 12221)
Operation
Worm Gear / Pneumatic / Electric

Product Overview

Gaoshan D363H series triple-offset hard-seal butterfly valve is the butt-weld end connection version of the D43H family. It is engineered for high-temperature and high-pressure applications where elastomer-seated valves reach their limits and where welded piping is preferred. The triple-offset design ensures the disc surface lifts completely clear of the seat throughout the entire stroke, eliminating rubbing contact and reducing operating torque. The laminated stainless-steel and flexible graphite disc seal handles continuous service up to 425°C. Butt-weld ends are standard, with worm gear handwheel as standard and pneumatic or electric actuator options available.

Model Designation Guide

Model CodePressureSize RangeEnd ConnectionDrive
D363H-10C / 16CPN10 / PN16DN80 – DN1800Butt-Weld (GB/T 12221)Worm gear handwheel
D363H-25C / 40CPN25 / PN40DN80 – DN1600Butt-Weld (GB/T 12221)Worm gear handwheel
D663H (Pneumatic)PN10 – PN40DN80 – DN600Butt-WeldPneumatic actuator
D963H (Electric)PN10 – PN40DN80 – DN1600Butt-WeldElectric actuator 380V/220V

Triple Eccentric (Triple Offset) Principle

Gaoshan D363H uses three independent offsets to achieve zero-friction, pressure-assisted sealing across the full pressure range:

Triple Eccentric Principle Diagram

 

Offset 1 — Shaft Behind Disc Centreline
The valve stem is positioned behind the disc sealing face, so that when the disc closes it contacts the seat ring with uniform circumferential pressure. This geometry ensures tight shut-off around the full seat circumference.
Offset 2 — Shaft Off Pipeline Centreline
The stem centerline is offset from the pipeline centerline. This eliminates interference between the disc and body during opening, preventing the rubbing wear that conventional butterfly valves suffer in the 10°–80° open range.
Offset 3 — Conical Seat Axis
The seat cone axis is set at an angle to the pipeline centerline. This makes the disc sealing surface a true cone: as it rotates into the seat, contact pressure is applied evenly around the full circumference, avoiding localised stress and seat damage.

The result is simple: the disc never touches the seat during most of the stroke. Contact happens only in the final few degrees before full closure. This reduces operating torque and eliminates wear on the seat ring. The valve achieves bidirectional tight shut-off that meets Gaoshan’s zero-leakage standard throughout its service life.

Triple Eccentric Principle Diagram

Triple Eccentric Principle Diagram — replace YOUR-IMAGE-URL with actual image

Laminated Flexible Metal Seat Disc

The D363H disc sealing face uses a laminated metal construction developed by Gaoshan, which gives better high-temperature performance than solid metal or elastomer seats:

High-Temperature Capability — up to 538 °C
The laminated disc assembly is built with thin stainless steel rings separated by flexible graphite gaskets. Because the graphite is not adhesively bonded to the steel rings, the disc can handle much higher temperatures than any bonded rubber seat design.
Low Stem Seal Leakage — 10–20 ppm
Gaoshan D363H stem packing is finished to 8 RMS on the shaft and 32 RMS on the gland bore, achieving shaft-seal leakage of 10–20 ppm. The packing can be replaced on-site without removing the valve from the pipeline.
Anti-Blowout Shaft Protection
Gaoshan D363H is designed with dual anti-blowout protection.The bottom stem is retained by an internal collar; the top stem uses a shoulder that bears against the body bore. Both features prevent stem ejection if packing fails or pressure surges occur.

D343H Structural Diagram

D363H Structural Diagram — replace YOUR-IMAGE-URL with actual image

Materials of Construction

ComponentStandardOptional
Body (阀体)Cast Steel (WCB)Stainless Steel (CF8, CF8M)
Disc (蝶板)Cast SteelStainless Steel; Duplex SS
Shaft (阀杆)Cast SteelStainless Steel (316)
Seat Ring (阀座)Carbon SteelStainless Steel; PTFE-lined; Rubber-lined
Laminated Disc SealStainless steel + Flexible Graphite laminateAll-SS laminate (high-temp); PTFE laminate (chemical)
Stem PackingFlexible GraphitePTFE; PTFE + Graphite composite

Applicable Media

Steam (High Pressure)
High-Temperature Oil
Water / Seawater
Natural Gas
Air / Compressed Air
Acid / Alkali Solutions
Salt / Brine Solutions
Pharmaceutical Process
Food & Beverage
Wastewater / Slurry
Weak Corrosive Media

Design & Inspection Standards

Design / ManufacturingEnd ConnectionFace-to-Face LengthPressure Test & Inspection
JB/T 8527GB/T 12221 (Butt-Weld)GB/T 12221GB/T 13927

Connection Dimensions — D363H (Butt-Weld, DN80–DN1800)

Unit: mm  |  Dn=pipe bore, H0=face-to-face length, H=height, A=width, B=depth, G=gear handwheel diameter

 

1.6 MPa (PN10/16) — D363H-10C / 16C

DNNPSLDnH0HABG
803″18878918522550144180
1004″19010611710024550144180
1506″21015917218031063200300
2008″23020622320536063200300
25010″27025927823539580230350
30012″27030832926542580230350
40016″310387413335520125260400
50020″350488516405615125370400
60024″350591629465665160398500
70028″430693721540760200418600
80032″470793825625865200418600
100040″55099610297551030263510700
120048″630119412358801165333550800
140056″7101394144010101335333550800
160064″7901594164011251470374590900
180072″8701794184012401585374590900

4.0 MPa (PN25/40) — D363H-25C / 40C (DN80–DN1600)

DNNPSLDnH0HABG
804″18078918522550144180
1004″19010211710024556144180
1506″21015417218031080230350
2008″23020322320536080230350
25010″27025527823539580230350
30012″27030532926542580230350
40016″310387413340620160398500
50020″350488516405615125370400
60024″350591619500740200418600
70028″430686721540760200418600
80032″470793825625865200418600
90036″5108899278901010333550800
100040″55099610297551040333550800
120048″630119412358801165333550800
140056″7101394144010101355374590900
160064″7901594164011251470374590900

Key Features & Advantages

Zero-Friction Open / Close
The third eccentricity makes the disc lift completely clear of the seat during the whole stroke. No rubbing occurs at any opening angle, which greatly extends service life in frequent-cycle duty.
Pressure-Assisted Seal
Line pressure pushing on the disc cone increases seat contact force. The higher the pressure difference, the tighter the seal. Gaoshan D363H achieves zero-leakage performance in both flow directions.
High-Temperature Metal Seat
Gaoshan D363H uses a laminated stainless-steel and flexible graphite disc seal rated for continuous service up to 425°C, suitable for superheated steam and thermal oil applications.
Butt-Weld End Connection
D363H uses butt-weld ends conforming to GB/T 12221. Welded connection eliminates flange leakage paths and is preferred for high-pressure steam and high-temperature oil pipelines.
Uniform Seat Compression
The inclined cone seat geometry applies even contact pressure around the full seat ring, avoiding localised stress that causes soft-seat valves to leak at the disc edges.
Wide Actuator Compatibility
Gaoshan D363H has an ISO 5211 top flange for direct mounting of worm gear, pneumatic, or electric actuators without extra brackets.

Request a Quote or Technical Consultation

Gaoshan D363H butt-weld triple eccentric hard-seal butterfly valve is available in PN2.5 to PN40, DN80 to DN1800. Custom body materials, seat options, and actuator configurations are available. Contact our engineering team for sizing, torque calculation, and certification support.

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