Double Eccentric Butterfly Valve

Application Water plants, power plants, steel smelting, chemical industry, water source projects, municipal environmental‑protection engineering, water supply and drainage pipeline systems for flow regulation and shut‑off service.

Message

Product Details

Double Eccentric Butterfly Valve

Product Overview

Double eccentric butterfly valve, also known as high‑performance butterfly valve, is improved on the basis of single eccentric butterfly valve. The spindle center of the valve stem deviates from both the center of the butterfly disc and the center of the valve body. When the valve opens, the butterfly disc quickly disengages from the valve seat, which greatly eliminates excessive squeezing and scraping between disc and seat. It reduces operating torque and wear, and extends the service life of valve seat. Metal seat is available for high‑temperature working conditions.

This valve is widely used in water plants, power plants, steel smelting, chemical industry, water source projects and environmental protection facilities for drainage systems. It serves as regulating and intercepting equipment especially for waterway pipelines. Compared with center‑line butterfly valve, it delivers higher pressure resistance, longer service life and better stability. For large‑diameter sizes, it features lighter weight and lower overall cost. It achieves bi‑directional zero‑leakage sealing and can be applied under ultra‑high vacuum conditions.

Design & Test Standards

Item	Standard
Design & Manufacture	API 609, EN 593, GB/T 2238
Flange Standard	GB/T9113, EN1092‑2, ASME B16.5 Class150 / 300
Face‑to‑Face Dimension	EN558‑1 Series13/14, ISO5752
Top Mounting Flange	ISO 5211 (for electric / pneumatic actuator mounting)
Shell & Seal Test	API 598, ISO 5208, EN12266‑1

Technical Specifications

Item	Parameters
Nominal Size	DN50 ~ DN1600 (2"‑64")
Nominal Pressure	PN10, PN16, PN25; Class150LB, Class300LB
Connection Type	Wafer, Lug, Double Flange
Operation	Worm‑gear manual, electric, pneumatic, hydraulic, lever handle
Sealing Type	Soft seat (EPDM / NBR / Viton); Metal hard seat
Working Temperature	-20℃ ~ +425℃ (subject to material of seal and valve body)
Applicable Media	Water, sewage, steam, oil, gas and partial chemical media

Bill of Material

Item	Part Name	Standard Material	Optional Material
1	Valve Body	GGG50 Ductile Iron	WCB Carbon Steel, CF8(304), CF8M(316L) Stainless Steel
2	Butterfly Disc	GGG50 Ductile Iron	SS304 / SS316L, nickel‑plated anti‑corrosion treatment
3	Valve Stem	420 Stainless Steel	SS316, 17‑4PH high strength stainless steel
4	Seat / Seal Ring	EPDM (soft seat)	NBR, Viton, hard‑alloy metal seat (hard sealing)
5	Bearing	Bronze + PTFE composite bearing	Stainless steel bearing
6	Gland & Packing	Graphite / EPDM	PTFE packing

Product Features

Reasonable design with compact structure, easy for assembly, disassembly and maintenance.
Double‑eccentric structure reduces friction of sealing ring and prolongs valve service life.
Bi‑directional complete sealing with zero leakage, suitable for ultra‑high vacuum conditions.
Various media and temperature ranges are available by replacing materials of butterfly disc, valve shaft and sealing ring.
Light‑weight for large‑diameter sizes, low pipeline load and lower comprehensive project cost.

Application

Water plants, power plants, steel smelting, chemical industry, water source projects, municipal environmental‑protection engineering, water supply and drainage pipeline systems for flow regulation and shut‑off service.