API 6D ASTM Carbon Steel Triple Eccentric Hard Seal Flange High-Temperature Butterfly Valve for Water

Specification

TIANYU Stainless Steel High-Temperature & High-Pressure Resistant Multi-Level Metal Hard Sealing Butterfly Valve: A Powerful Tool for Industrial Fluid Control in Harsh Conditions

In industrial scenarios such as petrochemical, power energy, and metallurgy that involve high temperatures and pressures, valves face strict requirements for sealing performance, heat resistance, and structural strength. The TIANYU stainless steel high-temperature & high-pressure resistant multi-level metal hard sealing butterfly valve, with its innovative design and exquisite craftsmanship, becomes a reliable choice for complex working conditions, providing efficient and safe solutions for industrial fluid control.

I. Analysis of Core Product Features

(A) Multi-Level Metal Hard Sealing Structure

TIANYU’s butterfly valve adopts a unique multi-level metal hard sealing design, composed of a disc, seat, and multiple layers of metal sealing pairs. The seat uses Stellite alloy surfacing technology, with a surface hardness of up to HRC60, offering excellent erosion and wear resistance. The disc and seat are precisely matched through a conical surface, forming a multi-level sealing line that achieves zero leakage under high temperature and pressure. Tested at PN40 pressure and 425℃, the leakage rate is below 1×10⁻⁹m³/s, meeting the API 598 Class VI sealing standard, suitable for controlling flammable, explosive, and highly corrosive media.

(B) High-Temperature & High-Pressure Resistant Material System

Component	Material	Performance Advantages
Body/Disc	316L stainless steel (CF3M)	Molybdenum content increased to 2.2%-3.0%, resistant to 650℃, 40% enhanced chloride corrosion resistance
Stem	25Cr2MoV alloy steel	Quenched, tempered, and nitrided to hardness HV700, tensile strength ≥1000MPa, blowout-proof design compliant with ASME B16.34
Sealing Pair	Stellite alloy + Inconel alloy	Maintains excellent sealing and wear resistance at high temperatures (600℃), service life >8 years

(C) Double Eccentric + Conical Sealing Design

Combining the double eccentric structure with a conical sealing surface, the disc disengages from the seat instantly during opening, reducing friction and wear. During closing, the conical sealing surface gradually fits as the angle changes, forming a self-tightening seal—the higher the pressure, the better the sealing effect. This design reduces the opening/closing torque by 30% and avoids jamming caused by high-temperature expansion, ensuring long-term stable operation.

II. Key Technical Attributes

Parameter Category	Technical Indicators	Expansion Options
Size Range	DN50-DN800 (2″-32″)	Customizable extra-large DN1000 (negotiable)
Pressure Rating	PN16/PN25/PN40 (up to 4.0MPa)	American Standard Class 150-Class 600 (optional)
Applicable Temperature	-20℃-650℃ (standard type)	Special customization for low-temperature -196℃ (liquid nitrogen) and high-temperature 800℃
Connection Type	Flange connection (GB/T 9113, ANSI B16.5)	Butt-welded, wafer-type interface customization
Compliance Standards	GB/T 12238, ISO 5281	API 609, CE, fire certification (API 607)

Product Overview

III. Precision Manufacturing Processes and Quality Control

(A) Manufacturing Process Analysis

Body Molding: The 316L stainless steel body is produced by centrifugal casting, resulting in a dense and uniform internal structure. Double testing by ultrasonic testing (UT) and radiographic testing (RT) ensures no shrinkage cavities, pores, or other defects. High-temperature solution treatment relieves internal stress and improves material toughness.
Sealing Surface Processing: The seat is ground by a five-axis CNC grinder with flatness error ≤0.01mm and surface roughness Ra≤0.4μm. The Stellite alloy surfacing layer is ≥3mm thick, aged at high temperature to ensure hardness and wear resistance.
Assembly and Testing: High-precision assembly is completed in a dust-free workshop to ensure component clearances are controlled within 0.02mm. Each valve must pass a 1.5x nominal pressure hydrostatic strength test (30-min hold), a 1.1x air pressure seal test (helium leak detection), and a sampling of 100,000 opening/closing life tests.

(B) Quality Assurance System

Material Traceability: Batch numbers of key components can be traced to heat numbers and chemical composition reports, supporting third-party PMI material testing.
Third-Party Certification: Provides pressure resistance, high-temperature, and sealing performance test reports from institutions like SGS and BV.
System Certification: Certified by ISO 9001 quality management system, with high-pressure models complying with API 609 standards.

Valve Details

V. TIANYU Brand Customization Advantages

With over 15 years of industrial valve manufacturing experience, TIANYU offers end-to-end customized services:

In-Depth Technical Customization: Supports non-standard pressure ratings (up to PN100), extreme temperatures (-196℃-800℃), special materials (Hastelloy, duplex steel), and explosion-proof designs (Ex d IIC T6), providing 3D modeling and CFD fluid simulation analysis.
Efficient Delivery Capability: Regular orders delivered within 30 days, small batch customization (MOQ 1 units) shortened to 15 days, and a 72-hour emergency channel for urgent orders.
Global Service Network: Offers an 18-month warranty, 24/7 response from three major service centers covering APAC, Europe, and North America, 48-hour airfreight for critical spare parts, and supporting digital installation manuals and remote operation maintenance.

Application

IV. Product Application Scenarios

Petrochemical Industry: Controls media like hydrogen and ethylene in high-corrosion, high-temperature, and high-pressure pipelines of cracking units and hydrogenation reactors to prevent leakage risks.
Power Energy Sector: Enables quick on/off and flow regulation for main steam pipelines (10.0MPa/540℃) in power plants, with high-temperature resistant materials ensuring long-term stable operation.
Metallurgy Industry: Isolates and controls blast furnace gas and oxygen pipelines (3.0MPa/600℃), with multi-level sealing effectively resisting medium erosion.
Coal Chemical Industry: Provides safe shut-off for syngas pipelines (4.0MPa/550℃) in gasifiers, with zero-leakage design ensuring production safety.