Specification

Newway Triple Offset Metal Hard-Seal Flanged Butterfly Valve: Reliable Control for Harsh Industrial Conditions

I. Product Technical Overview

The Newway triple offset metal hard-seal flanged butterfly valve features a triple-eccentric geometry (offsets between the stem axis, disc center, sealing surface centerline, and disc rotation axis). Equipped with a worm gear actuator, it uses ductile iron/WCB body, stainless steel disc with Stellite hard-seal coating, and stainless steel stem. Designed for high-temperature (≤425℃), high-pressure (≤6.4MPa), corrosive/abrasive media (e.g., petrochemical steam, power plant desulfurization slurry, metallurgical gas, municipal heating), it meets strict shut-off and regulation needs in industrial piping systems.

II. Core Advantages

(A) Triple-Eccentric Structure: Zero Friction & Self-Tightening Seal

Three Offsets:

Radial offset (stem vs. disc center).

Axial offset (stem vs. sealing surface centerline).

Angular offset (sealing surface vs. disc rotation axis).
The disc disengages from the seat within 5° of opening (near-zero friction) and self-tightens during closing, achieving ANSI/FCI 70-2 Class VI bubble-tight leakage (metal-to-metal seal).

Extended Lifespan: Eliminates seal wear during operation, doubling service life in abrasive media (e.g., blast furnace gas) compared to double-offset valves.

(B) Metal Hard-Seal System: Harsh Condition Adaptability

Seal Technology:
The disc’s sealing surface uses Stellite 6/21 hard alloy overlay (≥2mm thickness) via plasma cladding, ensuring ≥200MPa bond strength, HRC 45-55 hardness, and resistance to 800℃ short-term heat and particle erosion (e.g., coal dust, slag).

Bidirectional Sealing:
Combines triple eccentricity with metal sealing for bidirectional zero leakage, suitable for high-temperature steam (350℃, 4.0MPa) and corrosive slurries (pH 2-12).

(C) Worm Gear Actuation: High Torque & Precision

Torque Efficiency:
Worm gearboxes (ratio 1:30–1:60) deliver ≥1000N·m torque (DN300), ideal for large diameters (≤DN1200). Manual operation requires ≤80N·m (API 609 compliant).

Mechanical Lock:
Worm gear drive provides self-locking to prevent disc movement from media backpressure, ensuring system safety (e.g., high-pressure steam lines).

(D) Material Synergy: Corrosion & Strength Balance

III. Technical Specifications

Product Overview

IV. Manufacturing & Quality

(A) Precision Manufacturing

Body Casting:

Ductile iron: Lost foam casting + annealing (ferrite ≥85%).

WCB: Resin sand casting + normalizing/tempering (grain size ≥6).

NDT: 100% UT (WCB) / MT (ductile iron), defects ≤JB/T 6059 Level 2.

Disc & Seal Processing:

Stainless steel disc: 5-axis CNC machining (roundness ≤0.02mm, Ra≤0.8μm).

Stellite overlay: Plasma cladding (≥2mm thickness, 500-hour salt spray tested).

Actuator Assembly:

Worm gearbox: Precision hobbing (class 6 accuracy, backlash ≤0.05mm).

Valve testing: 1.5× hydrostatic (30-minute hold), 1.1× helium leak (≤1×10⁻⁴ mbar·L/s).

(B) Quality Assurance

Traceability: Material heat numbers, CMA reports, and third-party PMI testing.

Certifications: ISO 9001, API 609, ATEX II 2G Ex db IIC T4 (explosion-proof).

Warranty: 24-month coverage for manufacturing defects (seal failure, structural deformation).