covnaactuator-butterfly-valve-structure

Double Offset Butterfly Valves VS Triple Offset Butterfly Valves

In recent years, the use of butterfly valves has become more and more widespread. According to the material of the butterfly valve, it can be divided into stainless steel butterfly valve, cast iron butterfly valve, cast steel butterfly valve and plastic butterfly valve. According to the seals of butterfly valves, butterfly valves can be divided into soft-sealed butterfly valves and hard-sealed butterfly valves. At the same time, according to the eccentric type, butterfly valves are divided into single eccentric type, double eccentric type and triple eccentric type.
Although many people know the working principle of butterfly valves, there are still many people who have doubts about eccentric butterfly valves. In this article, we will try our best to explain to you what an eccentric butterfly valve is to help you choose a better valve in the future.

Source: https://instrumentationtools.com/types-of-butterfly-valves/

What is a double eccentric butterfly valve?

Its structural feature is that the axis of the valve stem deviates from the center of the butterfly plate and the center of the body. The double eccentric effect enables the butterfly plate to be released from the valve seat immediately after the valve is opened, which greatly eliminates unnecessary excessive extrusion and scratching of the butterfly plate and the valve seat, reduces the opening resistance, reduces wear and improves The life of the valve seat is improved.

Advantages of double eccentric butterfly valve

● Good sealing performance
● Long lifespan

Application

● Double eccentric butterfly valves are widely used, such as oil and gas, HVAC, wastewater treatment, shipbuilding, food processing, etc.

What is a triple eccentric butterfly valve?

The structural feature is that the conical axis of the sealing surface of the butterfly plate is skewed to the cylinder axis of the body while the position of the axis of the double eccentric valve stem is eccentric. After the third eccentricity, the butterfly valve can withstand high temperature, high pressure and zero leakage.

Advantages of triple eccentric butterfly valve

Triple eccentric butterfly valve can be used in pipelines that require high pressure or high temperature

Application

● Triple eccentric butterfly valves are widely used in industries that require high temperature or high pressure, such as oil refining, power generation, pulp and paper, chemical, petrochemical, etc.

Actuation

Whether it is a double eccentric butterfly valve or a triple eccentric butterfly valve, it can be controlled manually, electrically, or pneumatically.

covnaactuator-butterfly-valves

How Butterfly Valve Works

Butterfly valves are one kind of valve that are used to start, shut off, and control fluid flow. Widely used in various industries, including HVAC, power plant, water treatment, oil and gas, paper and pulp, etc. Due to the wide size of the butterfly valve, it is very suitable for use in large pipelines.

Source: saVRee

According to the design type, the butterfly valve can be divided into single eccentric butterfly valve, double eccentric butterfly valve and triple eccentric butterfly valve, suitable for application that has pressure needs.

At the same time, butterfly valves can also be made into wafer type, lug type, flange type and clamp type, suitable for different valve needs.
More importantly, the butterfly valve can be made into a soft seal type or a hard seal type, which is suitable for controlling different types of media.

Both butterfly valves and ball valves are industrial valves with a 90-degree turn. The butterfly valve is rotated by the handle or hand wheel, so that the valve stem drives the valve plate to rotate 90 degrees to open or close the valve.

Butterfly valve body: The valve body is used to cover and protect the internal parts of the butterfly valve. The valve body can be made of stainless steel, WCB, Cast iron or plastic to meet the requirements of different industries. At the same time, the outer edge of the valve body will have a linking method for linking with the pipeline for use in the project.

Valve plate: When the valve is closed, the valve plate will be perpendicular to the medium. When the valve is open, the valve plate is parallel to the medium. At the same time, the valve plate can be partially opened or closed, allowing a certain amount of medium to pass through, thereby playing a regulatory role.

Handle or actuator: The ISO5211 standard connection plate of the butterfly valve means that it can be driven by a handle or remotely controlled by an actuator.

We can provide pneumatic actuators and electric actuators for your choice. If you use an electric actuator, you can easily achieve the purpose of the remote control. If you use a pneumatic actuator, you can reduce the cost, and this operation is the fastest actuation way.