TIANYU WCB Body SS316 Disc Double Offset Butterfly Valve – DN600 150LB Flange-to-Flange NBR Soft Seal Valve for Industrial Fluid Control (API 609/ASME B16.34/ASME B16.5 Compliant)

I. Product Overview

II. Important Attribute Specifications

A. Dimensional & Pressure-Temperature Parameters

• Port Size: DN600 (24”), with a size range spanning DN50 to DN1200 (2” to 48”) to accommodate varying pipeline scales. The double offset design ensures full-bore flow when fully open, minimizing pressure drop (Cv value up to 1800 for DN600) and optimizing energy efficiency in high-flow applications.
• Pressure Rating: 150LB (PN20), suitable for medium-pressure industrial systems. Hydrostatic testing follows API 598 protocols: 1.5× rated pressure (225LB/PN30) for the valve body (shell) and 1.1× rated pressure (165LB/PN22) for the seat, with zero tolerance for leakage, sweating, or structural deformation.
• Temperature Range: -20℃ to 120℃, limited by the thermal stability of the NBR soft seal. This range covers most industrial fluids, including ambient water, heated oil, and non-extreme-temperature chemicals.

B. Material Composition

• Valve Body: WCB Carbon Steel (ASTM A216 Grade WCB), a cast alloy with tensile strength ≥485MPa and yield strength ≥240MPa. It undergoes annealing heat treatment (850–900℃, slow-cooled) to reduce brittleness and relieve casting stresses, enhanced by a gray epoxy coating for external corrosion protection.
• Butterfly Disc: SS316 Stainless Steel (ASTM A182 Grade F316), containing 16–18% chromium, 10–14% nickel, and 2–3% molybdenum—engineered for chloride and chemical corrosion resistance. The disc is precision-machined to a Ra ≤0.8μm surface finish.
• Sealing Material: NBR (Nitrile Butadiene Rubber) soft seal, molded to 2–3mm uniform thickness with 60–70 Shore A hardness. It exhibits oil resistance, tensile strength ≥15MPa, and elongation ≥300% for reliable sealing.
• Valve Stem: SS316 Stainless Steel (ASTM A182), featuring an anti-blowout design and Ra ≤0.4μm polished finish to minimize friction.
• Flanges & Fasteners: Integral WCB flanges (ASME B16.5 RF finish) paired with ASTM A193 B7 bolts and ASTM A194 2H nuts for high tensile strength and vibration resistance.
• Gaskets: Spiral-wound (stainless steel/graphite, ASME B16.20) for leak-tight flange sealing.

C. Connection & Operational Features

• Connection Type: Flange-to-Flange (ASME B16.5), mating directly with pipeline flanges via through-bolts for alignment accuracy.
• Operation Mode: Manual (worm gear operator, torque reduction 6–10×) as standard; optional pneumatic (double-acting/spring-return), electric (4–20mA control), or hydraulic actuators.
• Functional Features: Double offset geometry (seat disengagement during operation), bidirectional sealing, ANSI/FCI Class VI leakage, and corrosion-resistant material pairing.

D. Certifications & Compliance

• Design Standards: API 609, ASME B16.34, ASME B16.5, API 598
• Quality Certifications: ISO 9001, CE
• Performance Certifications: ANSI/FCI Class VI, ISO 6283 (Cv testing)

III. Feature Description

A. Double Offset Design: Friction Reduction & Seal Longevity

• Seat Disengagement: As the stem rotates, the disc lifts away from the NBR seat before rotating—eliminating sliding friction that causes premature seal wear. In a chemical solvent line, this extended seal life from 18 months to 6 years.
• Low Operational Torque: The eccentric geometry reduces torque demand by 40–60% vs. concentric models; a DN600 manual valve requires only 180 N·m of torque for operation.
• Bidirectional Reliability: Consistent sealing in both flow directions simplifies pipeline layout, eliminating installation orientation constraints.

B. Material Synergy: Durability & Corrosion Resistance

• WCB Body: Cast WCB offers high tensile strength for heavy-duty systems, with an epoxy coating protecting against outdoor corrosion (rust-free for 5+ years in refinery piping racks).
• SS316 Disc: Molybdenum-enhanced corrosion resistance handles seawater, saline chemicals, and acids—no pitting observed after 7 years in a seawater cooling system (vs. 3-year failure for 304 steel).
• NBR Soft Seal: Oil resistance and moderate temperature tolerance suit hydrocarbon fluids (e.g., diesel) and industrial chemicals; 5-year service life in automotive coolant lines (outperforming EPDM).

C. Flange-to-Flange Connection: Installation & Maintenance Efficiency

• Alignment Accuracy: Integral ASME B16.5 flanges ensure precise mating with pipeline flanges, minimizing leak risks in large-diameter systems.
• Easy Maintenance: Valve removal for repairs requires no adjacent pipeline disassembly—reducing downtime from 8 hours to 2 hours in refinery process lines.
• Scalability: Compatible with standard flanges across DN50–DN1200, ensuring consistent installation practices in large facilities.

D. Soft Seal Performance: Leak-Tight Reliability

• Bubble-Tight Shut-Off: ANSI/FCI Class VI leakage (≤60 mm³/min for DN600 water) complies with strict environmental and health regulations.
• Elastic Resilience: The rubber seal compensates for pipeline misalignments and thermal expansion, maintaining integrity in fluctuating (20–90℃) power plant cooling lines.
• Chemical Compatibility: NBR works with aliphatic hydrocarbons, oils, and mild acids—versatile for multi-process facilities.

IV. Manufacturing Process

A. Material Inspection & Preparation

• WCB Body: Spectral analysis (chemical composition), ultrasonic testing (internal defects), and mechanical testing (ASTM A216 compliance) with MTR documentation.
• SS316 Disc: Chromium/nickel/molybdenum content verification (ASTM A182) and salt spray corrosion testing.
• NBR Seal: Hardness, tensile strength, and elongation testing to confirm 150LB/120℃ compatibility.

B. Valve Body & Disc Fabrication

• Body Manufacturing: WCB cast blanks are annealed, shot-blasted, and CNC-machined (5-axis) to ASME B16.5 tolerances (flange flatness ≤0.05mm/m).
• Disc Fabrication: SS316 bar stock is turned/milled to the double offset profile, ground to Ra ≤0.8μm, and passivated for corrosion resistance.
• Seat Preparation: Body seat pockets are grit-blasted (Ra 12.5–25μm) to enhance NBR adhesion.

C. Seal & Actuator Assembly

• Seal Bonding: NBR is molded to the seat pocket and heat-bonded for uniform adhesion, then trimmed to match the disc profile.
• Stem & Disc Assembly: SS316 stem is keyed to the disc; graphite-PTFE packing (10–15% compression) balances sealing and torque.
• Actuator Mounting: Worm gear/automated actuators are laser-aligned (stem runout ≤0.05mm) via ISO 5211 flanges.

D. Quality Testing & Certification

• Hydrostatic Testing: 1.5× rated pressure (shell) and 1.1× rated pressure (seat) per API 598, with zero leakage.
• Operational Testing: 100 open/close cycles to verify torque and seal integrity; automated actuators calibrated to 4–20mA signals.
• NDT & Flow Testing: Liquid penetrant (PT) for welds; magnetic particle (MPI) for WCB bodies; ISO 6283 Cv testing.

E. Final Inspection & Documentation

• Visual Inspection: Surface defect checks, laser-etched marking (size/pressure/material), and ASME B16.34 compliance verification.
• Documentation: MTRs, test reports, and compliance certificates (API 609, ISO 9001) included with each valve.

V. Product Advantages

A. Extended Service Life

B. Reduced Operational Costs

• Low Torque: 30–40% lower actuator energy use (electric models); $20,000/year savings for 20 DN600 valves in a refinery.
• Minimized Downtime: Flange-to-flange design cuts maintenance downtime by 75% in municipal water plants.

C. Regulatory Compliance

D. Versatility

E. Easy Installation

VI. Product Applications

A. Chemical & Petrochemical Industry

• Chemical Processing: Regulates solvents/acids in reactors; SS316 resists corrosion, NBR handles hydrocarbons.
• Petrochemical Refining: Controls gasoline/diesel flow in distillation lines; NBR seal ensures oil resistance.

B. Oil & Gas Industry

• Midstream Transmission: Manages NGL flow in pipelines; flange-to-flange design simplifies large-diameter installation.
• Downstream Distribution: Regulates fuel oil flow to industrial customers; leak-tight sealing prevents product loss.

C. Power Generation

• Thermal Plants: Controls cooling water flow; WCB body withstands mechanical stress, NBR handles temperature fluctuations.
• Biomass Plants: Manages process water/slurries (reinforced NBR for mild abrasion).

D. Municipal Water Systems

• Potable Water: Regulates city mains; NBR complies with FDA potable water standards.
• Wastewater Treatment: Controls influent/effluent; SS316 resists chlorinated wastewater corrosion.

E. General Manufacturing

• Automotive: Manages coolant/lubricant flow; NBR’s oil resistance ensures long service life.
• Food & Beverage: Controls process water (optional EPDM for FDA compliance).

Customization Advantages