What is Eccentric/Offset Butterfly Valve

Eccentric/Offset Butterfly Valves means the axis of the valve stem deviates from the center of the butterfly disc, so that the upper and lower ends of the butterfly plate no longer become the axis of rotation, dispersing and reducing excessive extrusion between the upper and lower ends of the butterfly disc and the valve seat.

The Eccentric/Offset butterfly valve devide into double eccentric butterfly valve(two offset butterfly valve) and triple eccentric butterfly valve(three offset butterfly valve).

Double eccentric butterfly valve

Double eccentric butterfly valve is the most widely used type. Its structural feature is that the axis of the valve stem is deviated from the center of the butterfly plate and the center of the valve body. It deviates from the two center positions, so it is called a two offset butterfly valve.

Triple eccentric butterfly valve

The triple eccentric butterfly valve has a third eccentricity on the basis of the double eccentric butterfly valve. The shape of the sealing pair is not a forward cone, but an oblique cone. The valve stem shaft of the triple eccentric butterfly valve is a three-section shaft structure. The two shaft sections of them are concentric, and the center line of the center section shaft is offset from the two end axes by a PCD.

please watch the video and picture right side.

differences among Eccentric butterfly valves

What Kind of Eccentric Butterfly Valve ZFA Make

awwa c504 double eccentric butterfly valve
double eccentric butterfly valve

EPDM seat double offset butterfly valve 

double eccentric butterfly valve with gear

Why Choose US


ZFA VALVE factory Founded in 2006,  mainly produce concentric butterfly valves, eccentric butterfly valves, valve parts which compliance with valve international standard. We have got ISO, CE, Wras, API certificates etc.

OEM Capacity

We have 32 machines (include CNC, machine center, semi-auto machine, pressure testing machine, etc.)

The most important is that we have tens of molds in hand, such as wafer/flanged/lug valve body, disc, seat, handle molds.

Butterfly Valve Manufacturing Process

We’re a real butterfly valve factory with 17 years production experience, OEM for some customers around the world. All butterfly valves sold by ZFA VALVE are manufactured in our own factory. The excellent quality of our products comes from the meticulous management of the production process. ZFA VALVE is proud to show you our real production scene. Here is our motto: Rigorous production leads to excellent quality!

valve body raw material casting

Step 1: Casting


Step 2:Material Preparation


Step 3:Material Quality Inspection


Step 4:Machining Parts

spraying body

Step 5:Surface Treatment


Step 6:Assembly

pressure testing3

Step 7:Inspection And Quality Control


Step 8: Packaging


Step 9: Distribution

Producing Process of Butterfly Valve Parts


Valve Body of Butterfly Valve

butterfly valve disc machining

Valve Disc of Butterfly Valve

soft-backed seat butterfly valve

Soft-backed Seat of Butterfly Valve

Factory Overview

eccentric valve store

Get More Videos about MANUFACTURING PROCESS, and CAD DAWING about the butterfly valve, please contact us!


certificates wras of zfa valve
1. Who are you?
A: We are a professional butterfly valve manufacturer, who can provide DN15-DN3000 bfv valves.
2. What is function of butterfly valve?
A: Butterfly valve is also called ON-OFF valve, it is used for flow control: start and stop the fluid.
3. What is working principle of double eccentric butterfly valve?
A: When the sealing surface is closed, friction occurs between the disc and the valve seat, and the sealing effect is very good. It has the characteristics of small area and strong pressure. After the valve is opened, the butterfly plate can quickly separate from the valve seat, which greatly eliminates unnecessary excessive extrusion and scratching between the butterfly plate and the valve seat, reduces the opening resistance, reduces wear, and increases the service life of the valve seat.
4. What is working principle of triple eccentric butterfly valve?
A: Due to the effect of the eccentric shaft, when it is close completely, the butterfly plate moves a certain distance into the sealing cone surface of the valve seat, and the sealing surface of the butterfly plate and the valve seat matches to achieve reliable sealing performance. It makes up for the contradiction that hard seals which also named metal to metal seal have poor sealing, while soft seals have good sealing effects but are not resistant to high temperatures.
5. What is the connection method of the offset butterfly valve?
A: All wafer, double flange, and lug end are suitable for the eccentric bfv valve.
6. What is the actuator of the eccentric butterfly valve?
A: Worm Gear, Electric, and Pneumatic can be selectable.
7. Can you casting our Logo on the Valve body?
A: Yes, we provide OEM service, you can design your Logo and packing etc.

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