Telescopic Double Eccentric butterfly Valve Bidirectional Sealing Metal 4 Inch Double Offset butterfly Valve

Product Attribute: structure:BUTTERFLY
application:General
power:Manual
customized support:OEM
applicable medium:Water, Air, Gas, Oil, sTEAM
Product name:Telescopic double eccentric bidirectional seal metal butterfly valve
Keyword:metal seal butterfly valve
Calibration range:DN50~DN4000
Pressure level:1.0~2.5MPa
Temperature range:0℃~80℃
Transmission mode:Manual, electric, pneumatic, bevel gear
Applicable media:Water, steam, gas, oil, etc
Main material:QT450WCB, CF8

INFO@TYFLUIDGROUP.COM

Specification

Precision Manufacturing: Nanoscale Surface Engineering

Advanced Metallurgy

High-Temp Toughness: Ultra-low S/P CF8M bodies solution-annealed at 1100°C + cryo-treated (-196°C CVN ≥80J per ASTM A370).
Intergranular Corrosion Resistance: 0.15-0.25% nitrogen addition passes ASTM A262 Practice E.

Core Processes

Investment Casting:
- Silica sol molds, Ra≤125μin finish, 100% RT per ASTM E192.
Seal Surface Enhancement:
- Robotic PTA overlay (≤3HRC gradient) + diamond-ground to Ra≤4μin (flatness ≤0.0004″/in).
Bellows Fabrication:
- Electro-polished (Ra≤16μin) with 2nm passive layer; ISO 15848-1 BH certified.

Extreme Validation Protocol

Test	Standard	Condition	Acceptance
Thermal Cycling	API 607 Annex B	30x 600°C↔25°C shocks	No seal cracking
Telescopic Fatigue	EJMA Section 9	10k cycles ±15mm	Zero leakage
Bidirectional Sealing	ISO 5208	42MPa hydro / 6.9MPa pneum	Rate A zero visible
Torque Consistency	MSS SP-67	100k cycles	≤±5% variation

Performance Leadership: Redefining High-Temp Reliability

Parameter	TIANYU Valve	Conventional Competitor
Thermal Compensation	±15mm + ±3°	Requires expansion joints
Seal Life	≥250k cycles @600°C	≤80k cycles @300°C
Operating Torque	180Nm (DN600)	450Nm+ (DN600)
Maintenance Interval	10 years (in-situ seal)	3 years (full removal)
System Cost Savings	30% (eliminates joints)	Additional compensators

Product Overview

TIANYU Telescopic Double-Offset Bidirectional Metal-Seated Butterfly Valve: Dynamic Compensation Solution for High-Temperature Pipelines

In complex piping systems for petrochemical and power generation applications, thermal displacement compensation and zero-leakage sealing are critical operational challenges. TIANYU’s telescopic double-offset bidirectional metal-seated butterfly valve integrates dynamic expansion joints, dual-eccentric geometry, and multi-layer metal sealing to resolve stress deformation, seal failure, and maintenance downtime in high-temperature/pressure environments—redefining safety in modern industrial flow control.

Core Innovation: Thermal Self-Adaptation & Bidirectional Sealing

Engineered for extreme service (≤600°C / Class 600), this valve overcomes rigid structural limitations:

Axial Compensation: Stainless bellows absorb ±15mm axial displacement and ±3° angular deflection, eliminating flange bolt shear stress.
Bidirectional Pressure Integrity: Multi-layer seal stacks achieve ≤10⁻⁶ mbar·L/s helium leakage (per ISO 5208 Rate A) regardless of flow direction.

Breakthrough Engineering: Geometry Meets Material Science

1. Telescopic Bellows System

Hydraulic-Formed Layers: 100+ plies of 0.15mm 316L strip (≥20,000 cycles per EJMA).
Dynamic Stem Seal: Laser-welded bellows with high-temp grease (-40°C to 450°C) replace packing glands for zero fugitive emissions.

2. Double-Offset Geometry

Offset 1: Stem behind disc centerline reduces friction 85% during unseating.
Offset 2: 8° stem-to-pipe angle enables progressive metal contact (wear rate ≤0.005mm/10k cycles).

3. Bidirectional Metal Sealing

Disc: ASTM A995 4A duplex substrate with PTA-overlaid Stellite 6 (2.2±0.1mm; HRC 45-48).
Self-Compensating Seat: 12-disc spring stacks absorb 1.5mm wear while maintaining sealing stress.

Valve Details

TIANYU Advantage: Engineered for Dynamic Systems

Leveraging material failure analysis and fluid-structure simulation, we deliver:

Extreme Service Upgrades:
- Ultra-High Temp: Hastelloy bellows + aluminized silicon seals (800°C continuous).
- Severe Corrosion: Duplex bodies + Ta/W overlays (pH 1-14 resistance).
Predictive Health Monitoring:
- Real-time stress/temperature sensors with AI-driven failure prediction (200k+ test cycles).
Global Compliance:
- 19 certifications (ASME B16.34, API 609, PED Cat. IV, SIL 3 per IEC 61508).
Lifecycle Services:
- Pipeline thermal/vibration analysis + 48hr global spare parts response.

Application

Strategic Applications

Refinery Residue Lines: 580°C service; 90% leakage reduction vs. gate valve systems.
Concentrated Solar Power: Molten nitrate transfer (565°C); bellows absorb thermal growth.
Nuclear Steam Bypass: Class 600/540°C; 0.5 sec emergency closure.
LNG BOG Recondensation: -162°C cryogenic sealing integrity.