Specification

TIANYU Concentric Flanged Soft-Seal Butterfly Valve: An Efficient Universal Solution for Medium-Pressure Fluid Control

I. Product Basic Parameters and Core Positioning

Model: Concentric Butterfly Valve
Connection Form: Flanged (Flange Support, compatible with GB/T 9113, ANSI B16.5, ISO 7005 international flange standards)
Structure Design: Concentric Central Line Structure (stem axis, disc center, and pipeline centerline coaxial)
Seal Type: Soft Seal (elastic preload sealing, achieving zero leakage through rubber seat deformation)
Stem Design: Standard straight stem (no eccentric offset, axis perpendicular to pipeline center)
Working Pressure: Medium Pressure (PN10-PN40, 1.0MPa-4.0MPa, covering 2.5MPa＜Pn＜6.4MPa industrial conditions)
Working Temperature: Normal Temperature (-40℃＜T＜120℃, suitable for most water, gas, and oil media)
Body Material: Casting (CI cast iron/DI ductile iron/SS stainless steel)
Application Fields: Industrial pipeline systems, water industry (water supply/drainage, sewage treatment), civil buildings, general fluid transportation

II. Analysis of Core Technical Features

(A) Advantages of Concentric Central Line Structure

Maximized Flow Path Efficiency
- Geometric Coaxial Design: The stem, disc, and pipeline centerline are perfectly coaxial. When fully open, the disc aligns parallel to the fluid flow, with the flow coefficient Cv increased by 15%-20% compared to eccentric structures (pressure loss of DN100 valve ≤0.2m water column), ideal for high-flow scenarios (e.g., urban water mains, industrial circulating water pipes).
- 90° Precise On-Off: The disc completes opening/closing within a 90° rotation around the central axis. A mechanical limit device ensures an angle error ≤1°, with the handle position directly reflecting the opening degree for intuitive on-site operation and status monitoring.
Reliability of Soft Sealing
- Elastic Sealing Principle: EPDM/NBR rubber seats are fixed to the body via dovetail grooves or pressure rings, directly 贴合 the disc edge to form a bi-directional zero-leakage seal (leakage rate ≤5×10⁻⁸m³/s, conforming to EN12266 Class A standards) through medium pressure or preload.
- Serviceability Design: The seal seat supports online replacement (no pipeline disassembly needed), reducing maintenance time by 40% compared to hard-seal valves, suitable for long-term operation in municipal networks and sewage treatment where maintenance is difficult.

(B) Material System and Working Condition Adaptation

Component	Material Options	Performance Characteristics	Typical Applications
Body	Cast Iron (CI)	Cost-effective, suitable for general water and low-pressure civil use	Community water supply, irrigation pipes (PN10-PN16)
	Ductile Iron (DI/QT450)	High strength (tensile ≥450MPa), impact resistance (-40℃ impact energy ≥27J)	Industrial medium-pressure pipes, particle-containing sewage (PN25-PN40)
	Stainless Steel (CF8/CF8M)	Corrosion-resistant (chloride ≤200ppm), sanitary-grade	Food & pharmaceutical, seawater desalination, weak acid/base pipes
Disc	CI/DI with nickel plating	Surface roughness Ra≤3.2μm, nickel plating ≥25μm, resistant to sewage erosion	Sewage treatment plants, industrial wastewater pipes
	Stainless Steel (CF8/CF8M)	High-temperature oxidation resistance (short-term 150℃), intergranular corrosion resistance	Hot water circulation, steam tracing pipes
Seal Seat	EPDM (food-grade optional)	Water/drinking water resistant (WRAS/NSF61 certified), temperature -20℃~120℃	Drinking water pipes, air conditioning chilled water systems
	NBR	Oil/hydrocarbon resistant (ASTM No.3 oil test passed), temperature -40℃~100℃	Lubricating oil pipes, compressed air systems

(C) Characteristics of Flanged Connection

Installation Versatility: Flange sealing surfaces support RF (Raised Face)/RTJ (Ring Type Joint), with bolt hole spacing complying with international standards, adapting to global pipeline systems without additional flange spacing adjustments during installation.
Pressure Stability: Flange thickness is designed per ASME B16.5 standards. PN40 valve flanges are CNC-machined (flatness ≤0.03mm), ensuring no deformation under 1.5x nominal pressure, suitable for vibrating or high-pressure drop conditions (e.g., pump inlets/outlets).

Product Overview

III. Key Technical Parameters and Execution Standards

Parameter Category	Technical Indicators	Expansion Options
Nominal Diameter	DN40-DN1200 (1.5″-48″)	Custom DN1400-DN2000 (requires FEA strength analysis)
Pressure Class	PN10/PN16/PN25/PN40 (1.0-4.0MPa)	Class 150/300 (ASME standards, requires material upgrade)
Actuation Mode	Manual Handle (standard, DN40-DN300)	Worm Gear (DN300+, 30% labor saving), Electric/Pneumatic (explosion-proof optional)
Sealing Test Standards	API 598 (1.5x hydrostatic test), EN12266	Fire certification API 607 (metal seal redundancy design)
Applicable Media	Water, sewage, air, oil, neutral gases	Acid-base media (requires PTFE seal + SS body upgrade)

Valve Details

VI. Selection Tips and Customization Services

Media Adaptation:
- Clean water/drinking water: Prioritize EPDM seal + CI/DI body (WRAS certified);
- Oil/hydrocarbon media: Choose NBR seal + DI/SS body (with oil resistance test reports);
- Slight corrosion environments: Select SS304 body + EPDM/NBR; upgrade to SS316 + PTFE for strong corrosion.
Actuation Selection:
- Manual actuation: Suitable for DN40-DN300 in low-frequency operation scenarios (e.g., community valve wells);
- Power actuation: Electric/pneumatic actuators for automation control; explosion-proof type (Ex d IIC T6) for petrochemical and natural gas hazardous areas.

Application

IV. Manufacturing Processes and Quality Control

(A) Core Processing Flow

Valve Body Casting:
- CI/DI valves use lost foam casting, annealed at 900℃ to relieve internal stress, with graphite spheroidization rate ≥90% (DI material) to ensure anti-fracture performance in low temperatures.
- SS valves adopt investment casting, with surface pickling and passivation (blue point test qualified), meeting sanitary requirements for food & pharmaceutical industries.
Seal System Assembly:
- Rubber seats are compression-molded and interference-fitted with the body (clearance ≤0.02mm). Disc edges are rounded (R≥3mm) to reduce opening/closing friction. Each valve must pass 1.5x nominal pressure hydrostatic test (30-min hold, no leakage).
Drive Debugging:
- Manual handles connect to the stem via involute splines (fit tolerance H7/g6), with operating torque ≤50N·m (DN100). 100 cycle opening/closing tests ensure no jamming or seal wear.

(B) Quality Certification System

Material Traceability: Provides body heat numbers, chemical composition reports (CMA certified), supporting third-party PMI material testing to ensure CI/DI/SS compliance with ASTM A216/A536/A351 standards.
Performance Certifications: Drinking water valves are WRAS/NSF61 certified; industrial models hold CE-PED/ISO 9001; marine models are available with LR/DNV-GL classification society certifications.

V. Typical Application Scenarios

(A) Industrial Pipeline Systems

Cooling Water Circulation: DN300 DI body + NBR seal seat resists scale erosion in power plant condenser pipes (80℃, PN25), paired with worm gear drive for easy operation of large-diameter valves by single personnel.
Compressed Air Networks: DN150 SS body + EPDM seal meets 3A sanitary standards in pharmaceutical clean pipes, with flanged connections facilitating regular disassembly and cleaning in GMP workshops.

(B) Water Industry

Municipal Water Supply: DN600 CI body + food-grade EPDM seal, WRAS certified, achieves zero-leakage shut-off in urban water mains, adaptable to SCADA remote monitoring (with optional electric actuator).
Sewage Treatment: DN800 DI body with epoxy coating (thickness ≥200μm) resists corrosion in particle-containing sewage (≤1mm), extending seal life by 1.5x compared to ordinary butterfly valves.

(C) Civil Buildings and HVAC

HVAC Systems: DN50-DN200 flanged butterfly valves in commercial complex chilled water networks, with EPDM seals achieving compression set ≤5% at 70℃, enabling variable flow regulation with BA systems, reducing energy consumption by 12%.
Residential Applications: DN40-DN80 CI body + manual handle, lightweight and easy to operate, suitable for villa main water valves and water heater inlets/outlets. NBR seals effectively block household lubricant leakage.