Dd343H Three eccentric multi-level hard sealed flange butterfly valveDetailed product description：

Dd343H three eccentric multi-level hard sealed flange butterfly valve:

The three eccentric multi-level hard sealed flange butterfly valve series products are long-life and energy-saving butterfly valves. Its structure is designed using the three-dimensional core principle, and the valve seat adopts a multi-level structure compatible with hard and soft seals, with exquisite processing and advanced technology. This product consists of main components such as valve body, butterfly plate, multi-level valve seat, valve stem, and transmission mechanism. Therefore, it is widely used in pipelines for corrosive media such as metallurgy, electricity, petroleum, chemical, air, gas, combustible gases, and water supply and drainage.

structural characteristics

Due to the three-dimensional eccentric principle design used in this butterfly valve product, the spatial motion trajectory of the sealing surface is idealized, and there is no friction or interference between the sealing surfaces. In addition, the appropriate selection of sealing materials ensures reliable sealing, corrosion resistance, high temperature resistance, and wear resistance of the butterfly valve. Its main characteristics are as follows:
1. Small opening torque, flexible and convenient, labor-saving and energy-saving.
2. The three-dimensional core structure makes the butterfly plate tighter as it is closed, and its sealing performance is reliable, achieving no leakage.
3. High pressure resistance, corrosion resistance, wear resistance, long service life, etc.

Adopting standards

Design standard: GB/T12238-1989; JB/T8527-1997
Flange connection size:
GB/T9113.1-2000； GB/T9113.2-2000
GB/T9115.1-2000； GB/T9115.2-2000
Structural length: GB/T12221-1989
Pressure test: GB/T13927-1992; JB/T9092-1999

standard specification

Manufacturing Standard	GB12238-89	size standard	GB/T17241.6-98
structural length	GB12221-89	Inspection Criteria	GB/T13927-92

Main component materials

valve body	valve plate	valve seat	valve stem	filler
HT200 WCB 1Cr18Ni9Ti	HT200 WCB 1Cr18Ni9Ti	Nitrile rubber Ethylene Propylene Rubber fluororubber	forty-five 2Cr13 1Cr18Ni9Ti	flexible graphite

Main technical parameters

Nominal Diameter	DN（mm）	50~2000				50~500
Nominal pressure	PN（MPa）	zero point six	one	one point six	two point five	four
Test pressure	strength test	zero point nine	one point five	two point four	three point seven five	six
	Sealing Test	zero point six six	one point one	one point seven six	two point seven five	four point four
	gas tightness test	zero point six	zero point six	zero point six	zero point six	zero point six
leakage rate	＜ 0.1 × DNmm3/s (compliant with GB/T13927-92 standard)
Applicable temperature	Carbon steel: -29 ℃~425 ℃ Stainless steel -40 ℃~600 ℃
Applicable Medium	Air, water, steam, coal gas, oil products, as well as acids, alkalis, salts with weak corrosive media, etc
Drive Type	Worm gear transmission, pneumatic transmission, electric transmission

Material of Dd343H Three Eccentric Multi level Hard Sealed Flange Butterfly Valve Parts

Part Name	Material
valve body	Cast iron, stainless steel, chromium molybdenum steel, alloy steel
butterfly valve disc	Cast steel, alloy steel, stainless steel, chromium molybdenum steel
Seal ring	Combination of stainless steel and high-temperature resistant asbestos board into multiple layers
valve stem	2Cr13, 1Cr13 stainless steel, chromium molybdenum steel
Bearing	Austenitic stainless steel, 304 nitriding
filler	flexible graphite

Characteristics and principles of three eccentricities

1. Deviation from the center of the pipeline
2. Deviation from the center of the sealing surface
3. Tilted cone shape

When the valve is opened, the butterfly plate comes into instant contact with the valve seat when it is closed, and the eccentricity 1 and eccentricity 2 of the butterfly plate quickly detach from the valve seat, reducing the wear of the sealing pair, reducing the friction torque, and making it flexible to open. Eccentric cone surface 3 enables the butterfly plate to pass through the inner hole of the valve seat and achieve contact sealing when the valve is opened or closed. In addition, the rotation radius of the conical butterfly plate is greater than the rotation radius of the sealing pair contact position, so the butterfly plate will become tighter and tighter when the valve is closed, which can achieve self-locking and prevent the butterfly plate from exceeding its position.