According to the flange connection form, the butterfly valve body is mainly divided into: wafer type A, wafer type LT, single flange, double flange, U type flange.

Wafer type A is non-threaded hole connection, LT type 24" above large specifications usually use better strength U-type valve body to do threaded connection, the end of the pipeline needs to use LT type.

The V-shaped ball valve is features a V-shaped port on one side of the hemispherical valve core.
The flow channel opening of O-shaped ball valve is round, its flow resistance is small, and the switching speed is fast.


In the previous article, we talked about gate and globe valves, today we move on to butterfly valves and check valves, which are commonly used in water treatment.


  The valve is the control device of the fluid pipeline. Its basic function is to connect or cut off the circulation of the pipeline medium, change the flow direction of the medium, adjust the pressure and flow of the medium, and set various valves, large and small, in the system. An important guarantee for the normal operation of the pipe and equipment.

8. Electrical Wafer Butterfly Valve

The control valve flow coefficients (Cv, Kv and C) of different unit systems are control valves under a fixed differential pressure, the volume of water circulating in a unit of time when the control valve is fully open, Cv, Kv and C there is a relationship between Cv = 1.156Kv, Cv = 1.167C. This article shares the definition, unit, conversion and exhaustive derivation process of Cv, Kv and C.


Valve seat is a removable part inside the valve, the main role is to support the valve plate fully open or fully closed, and constitute the sealing vice. Usually, the diameter of the seat is the size of the valve caliber. Butterfly valve seat material is very wide, commonly used materials are soft sealing EPDM, NBR, PTFE, and metal hard sealing carbide material. Next we will introduce one by one...

flange check valve

  Check valve refers to the opening and closing parts for the round valve and rely on their own weight and media pressure to produce action to block the medium backflow of a valve. Check valve is an automatic valve, also known as check valve, one-way valve, non-return valve or isolation valve. 

check valve-8

Wafer check valves are also known as backflow valves, backstop valves, and backpressure valves. These kinds of valves are automatically opened and closed by the force generated by the flow of the medium itself in the pipeline, belonging to a kind of automatic valve.

AWWC 504-2

Butterfly valve because of its smaller size and simple structure, has become one of the most commonly used valves in the industry, more and more are applied to hydroelectric power, irrigation, building water supply and drainage, municipal engineering and other piping systems, used to cut off or mediate the flow of circulating media flow to use. Then the butterfly valve in the use of the problems that need attention and solutions to what, today we will be specific to understand.



Soft seal gate valves and hard seal gate valves are commonly used devices for regulating and intercepting flow, both have good sealing performance, a wide range of use, and are one of the products that customers purchase more. Some purchasing novices may be curious, the same as the gate valve, what is the specific difference between them


AWWA C504 Double Eccentric Butterfly Valve

AWWA standard is The American Water Works Association first published consensus documents in 1908. Today, there are more than 190 AWWA Standards. From source to storage, from treatment to distribution, AWWA Standards cover the products and processes related to all areas of water treatment and supply. AWWA C504 is of the typical representative, it is is a kind of rubble seat butterfly valve

big size butterfly valve-4

The big-size butterfly valves usually refer to butterfly valves with a diameter larger than DN500, usually connected by flanges, wafers. There are two kinds of large-diameter butterfly valves: concentric butterfly valve and eccentric butterfly valves.

triple offset butterfly valve

The three eccentricities of the Triple Eccentric Butterfly Valve are refer to:

The first eccentricity: the valve shaft is located behind the valve plate,allowing the sealing Ring to closely surround the entire seat in contact.

The second eccentricity: the spindle is laterally offset from the center line of the valve body, which prevents interference with the opening and closing of the valve.

Third eccentricity: the seat  is offset from the centre line of the valve shaft, which eliminates friction between the disc and seat during closing and opening.

The double eccentric butterfly valve is named after its two eccentric structures. So what is the double eccentric structure like?

The so-called double eccentric, the first eccentric refers to the valve shaft being off the center of the sealing surface, which means the stem is behind the valve plate face. This eccentricity makes the contact surface of both the valve plate and the valve seat a sealing surface, which fundamentally overcomes the inherent deficiencies that exist in concentric butterfly valves, thus eliminating the possibility of internal leakage at the upper and lower intersection between the valve shaft and valve seat.

Butterfly valve, also called flap valve, is a simple structure of the adjustment valve, that can be used in low pressure pipelines to shut off flow. Rotating around the valve shaft to achieve open and close a valve.

According to the different connection forms, it can be divided into wafer butterfly valve, lug butterfly valve, flange butterfly valve, welded butterfly valve, screw thread butterfly valve, clamp butterfly valve, and so on. Among the most commonly used connection forms are the wafer butterfly valve and lug butterfly valve.


The pneumatic butterfly valve is composed of a pneumatic actuator and a butterfly valve. Air actuated butterfly valve uses compressed air as the power source to drive the valve stem and control the rotation of the disc around the shaft to open and close the valve.

According to the pneumatic device can be divided into single-acting pneumatic butterfly valve and double-acting pneumatic butterfly valve.


Zhongfa Valve is a professional manufacturer of butterfly valve parts and butterfly valves, established in 2006, providing valves and butterfly valve parts products to more than 20 countries in the world, next, Zhongfa Valve will launch a detailed introduction of butterfly valve parts.


Butterfly valves are a family of quarter-turn rotational motion valves used in pipelines,   they are usually classified by construction and connection. ZFA is one of the famous wafer butterfly valve manufacturers, flange butterfly valve manufacturers, and lug butterfly valve manufacturers in China.

Types by Connection, they are four types.

ZFA Valve's electric butterfly valves are divided into the following two categories: centerline butterfly valves and eccentric butterfly valves, among which centerline butterfly valves are further divided into wafer butterfly valves, lug butterfly valves and flange butterfly valves.

Electric butterfly valves are assembled from butterfly valves and electric devices. It is widely used in petroleum, chemical, electric power, metallurgy, food, pharmaceutical, textile, paper and other industries. The medium are usually natural gas, air, steam, water, seawater and oil. Motor operated butterfly valves are used to regulate the flow and cut off the medium on industrial pipelines.

We can provide the following kinds of API609 butterfly valves:

According to the connection, we have double-flange butterfly valvewafer butterfly valve and lug butterfly valve;

According to the material, we can provide ductile iron material, carbon steel material, stainless steel material, brass material, super duplex steel material;

According to the process, we can provide API609 butterfly valve with casting body and welding body.

PTFE Lining Valve also known as fluorine plastic lined corrosion resistant valves, are fluorine plastic molded into the inner wall of the steel or iron valve bearing parts or the outer surface of the valve inner parts. Fluorine plastics here mainly include: PTFE, PFA, FEP and others. FEP lined butterfly, teflon coated butterfly valve and FEP lined butterfly valve are usually used in strong corrosive media.

Our wafer butterfly valves are compliance with valve international standard of ASTM, ANSI, ISO, BS, DIN, GOST, JIS, KS and so on. Size DN40-DN1200, nominal pressure: 0.1Mpa~2.5Mpa, suitable temperature: -30℃ to 200℃.

We mainly export to totally 22 countries like US, Russia, Canada, Spain etc.

n terms of material, stainless steel butterfly valves are available in SS304, SS316, SS304L, SS316L, SS2205, SS2507, SS410, SS431, SS416, SS201, In terms of structure, stainless steel butterfly valves are available in centric and eccentric lines. Centric line stainless steel butterfly valves are generally made of stainless steel for the valve body, valve plate, and shaft, and EPDM or NBR for the valve seat, They are mainly designed for flow control and regulation of corrosive media, especially various strong acids, such as sulphuric acid and aqua regia.