What kind of butterfly valves can we supply?

As one of the most professional manufacturers in China, we design and manufacture for years.

Cast Iron Butterfly Valve, Cast Carbon Steel Butterfly Valve, Cast Stainless Steel Butterfly Valve, Rubber lined Butterfly Valve, P.T.F.E. lined Butterfly Valve, Wafer Type Butterfly Valve, High Performance Butterfly Valve, Center Disc Butterfly Valve, Off-Set Disc Butterfly Valve, Gear operated Butterfly Valve, Pneumatic operated Butterfly Valve, Electrical operated Butterfly Valve, Zero Leakage Butterfly Valve, Double Flange Type Butterfly Valve, Bi-directional Butterfly Valve.

Butterfly Valve Features:
Concentric, Double Eccentric, Triple Eccentric Design
Excellent Sealing Capacity
Soft Seat / Hard Seat Design
Lower Torque with any fluid
Permanently tight closure
Bi-Directional Valve
Optimum operation under Vacuum Condition
Suitable for On-off as well as Throttling Service
Materials for almost all media
Short / Long Face To Face Dimension
Wafer, Lug, Double Flange, Butt-Weld Design Body
Long Service Life
Smooth, Easy Operation
Maintenance Free Version
Less Weight, Easy To Install

Butterfly Valve Design & Testing International Standard:
Valve Design: API 609, BS 5155, MSS SP-67, EN593, MSS SP-68, GB/T12238, AWWA C504
Pressure Testing: BS 6755-I, API 598, ISO 5208 etc
Face To Face: ANSI B 16.10, API 609, DIN3202-K1, EN558-1 20 Series, BS5155, MSS SP-67 etc
Flange Drilling: ANSI B 16.5, ASNSI B16.47, API 605, AWWA C207, BS 10 Table / DIN / IS / JIS Std.
Pressure Rating: Class 150, Class 300, Class 600, Class 900
Leakage Class: Class VI (Zero Leakage)
Size Range: DN50 to DN3000 (2” to 120”)
Operation: Up to DN200 lever operated, and above gear operated. On special request available for electric, pneumatic and hydraulic operated.

Butterfly Valve Material of Construction:
Body: Cast Iron to ASTM A 126 Class B / HT200 / HT250; Ductile Iron to ASTM A 536 Grade 65-45-12 / GGG40, GGG50; Cast Carbon Steel to ASTM A 216 GR. WCB / A352 LCB / LCC; Stainless Steel to ASTM A 351 GR. CF 8 / 8M / 3 / 3M; Alunium Bronze ASTM A148 B95500, C955800
Disc: Cast Iron to ASTM A 126 Class B / HT200 / HT250; Ductile Iron to ASTM A 536 Grade 65-45-12 / GGG40, GGG50; Cast Carbon Steel to ASTM A 216 GR. WCB / A352 LCB / LCC; Stainless Steel to ASTM A 351 GR. CF 8 / 8M / 3 / 3M; Aluminium Bronze ASTM B 148-C95400; Nylon Coating on C.I. / D.I. / WCB / S.S. Disc Material; EPDM / Neoprene / Hypalon / Nitrile Rubber / Buna-N; Rubber Encapsulated on C.I. / D.I. / WCB / S.S. Disc Material; P.T.F.E. (PFA / FEP) Lined on C.I. / D.I. / WCB / S.S. Disc Material
Seat (Liner): EPDM; EPDM Food Grade; Buna-N; Black Nitrile; Neoprene; Hypalon; Silicon; Viton; P.T.F.E.
Stem: AISI 410 (S.S. 410, 13% Cr. Steel); AISI 304 (S.S. 304); AISI 316 (S.S. 316); AISI 304L (S.S. 304L); AISI 316L (S.S. 316L); 17-4PH, Monel K400 / K500

Test Specification:
Body Test: 1.5 times the working pressure with water. This test is performed after valve assembly and with disc in half position open, it is called as a body hydro test. 
Seat Test: 1.5 times the working pressure with water.
Function / Operation Test
At the time of final inspection, each valve and its actuator (Flow-Control Lever / Gear / Pneumatic Actuator), under goes a complete operating test (Open/Close). This test carried out without pressure and at ambient temperature. It ensures the correct operation of the valve / actuator assembly with accessories such as solenoid valve, limit switches, air filter regulator etc.
Special Test On request, any other test can be carried out according to special instruction by client

Butterfly Valve Applications: Water Treatment Plant, Paper Industry, Sugar Industry, Breweries, Chemical Industry, Waste Effluent Treatment Plant, Drilling Rigs, Gas Plant, Cooling Water Circulation, Heating & Air Conditioning, Pneumatic Conveyors, Compressed Air

Please specify below details while you have enquiries/orders:
1.Types of Valve; 2. Pressure Rating Class; 3. Valve Size; 4. Type of End Connection; 5. Material of Construction; 6. Disc Material; 7. Rubber Seat Material; 8. Flow Medium (Service); 9. Design Pressure; 10. Operating (Working) Pressure; 11. Design Temperature; 12. Operating (Working) Temperature; 13.Type of Operation Manual / Pneumatic / Electric etc.

Please download our the below valve drawing for reference. It is metal hard seal, three eccentric design butterfly valve, available double flange, wafer type and lug type, as well as butt welded ends. It is just for technical evaluation if you have are interested in this products. Our design allows reduced torques and excellent throttling capabilities of the offset disc assemblies. The metal-metal seal assures a perfect tightness even at pressure and/ or temperature & pressure changes.

Materials: carbon steel WCB, LCB, LCC, LC1, LC3, stainless steel CF8, CF8M, CF3, CF3M, duplex steel 1A(CD4MCu) 2A(CE8MN) 3A(CD6MN) 4A(CD3MN) 5A(CE3MN) and aluminium bronze etc.
Size range: DN50 to DN3000, 2" to 120" nominal diameter.
Design standards: API 609, EN593, MSS SP-67, MSS SP-68, GB/T12238 etc
Face to Face dimensions: DIN3202-K1, EN558-1 20 Series, BS5155, MSS SP-67 etc
Design pressure: Pressure Rating ANSI Class 150#, Class 300#, Class 600#.
Working temperature:-29 ºC to + 425ºC, Special materials can be from -196°C to + 600°C.
End flange dimension: ASME B16.5 (for NPS not more than 24"), ASME B16.47 series B, API 605, ASME B16.47 series A (for NPS> 24"), or BS EN 1092.
Operation: lever, worm gear, pneumatic, electric, hydraulic or pneumatic-hydraulic actuator.
Charateristic: longer service life and available high temperature and pressure.
Application: is widely used in oil refining, chemical machinery industries, chemical and petrochemical processing, water pipeline system etc.
1. API 609 Triple Offset Butterfly Valve Drawing Flanged 150LB DN100~DN600
2. API 609 Triple Offset Butterfly Valve Drawing Flanged 150LB DN700~DN1500
3. API 609 Triple Offset Butterfly Valve Drawing Wafer 150LB DN100~DN600
4. API 609 Triple Offset Butterfly Valve Drawing Wafer 150LB DN700~DN1500
5. API 609 Triple Offset Butterfly Valve Drawing Lug 150LB DN100~DN600
6. API 609 Triple Offset Butterfly Valve Drawing Lug 150LB DN700~DN1500

D343H butterfly valve is wormgear operated, double flange, three eccentric (triple offset) metal seal structure butterfly valve. The seal is in the form of metal to metal, metal seals can be composited stainless steel and graphite combined sealing. It can be available manual, electric, pneumatic, hydraulic actuators etc.
D373H butterfly valve is wormgear operated, wafer type, three eccentric (triple offset) metal seal structure butterfly valve. The seal is in the form of metal to metal, metal seals can be composited stainless steel and graphite combined sealing. It can also be available manual, electric, pneumatic, hydraulic actuators etc.
And please pay attention to the flow questions for D343H butterfly valve and D373H butterfly valve when the valves are working in project:
1, We know the sealing ring are graphite and stainless steel SS304 composited material that is fixed in the valve disc. The disc is normally open status, the media will crash the sealing surface at the front erosion of seal ring, this will affect the sealing performance.
2. the structural limit, usually it is not suggested for below diameter DN200 valve, because the overall structure of the disc is too thick and the flow resistance is large.
3. Due to the principle of eccentric structure, the sealing surface of the valve plate and valve seat seal on the transmission of torque to the valve plate pressure to the valve seat. When it is in right flow status, the pressure is higher, the sealing is tigher. But when it is in reverse flow medium with media pressure, the seal may start to leak when the reverse pressure is back to the disc. So some customers ask us to design it bi-directional seal for triple offset butterfly valve. Usually it is single direction seal if not requested by customer.
 D343H butterfly valve and D373H butterfly valve is widely used in water supply system, foodstuff, beverage, pharmaceutics, boiler, oil refining, chemical machinery industries, chemical and petrochemical processing, power generating plants, pulp and paper manufacturing processing, desalination, steelmaking, coal and mining industries. Size range from 2" to 120", pressure range from Class 150Lbs to Class 600Lbs.

Nowdays, the electric valve has been widely used in power plants, petrochemical, iron and steel metallurgy, food processing and water treatment industries, especially for large enterprises that need to automatic control. Electric valve has create the condition of remote control for the valve so that the automation and intelligent of production systems become possible. However, the electric valves in system often can not shut down tightly in operation. It has made a lot of trouble for valve user and operator, seriously affected the valve life.

Wedge gate valve, globe valve and butterfly valve, they are to reply on the operational force on the sealing surface to ensure sealing. And the sealing surface than the pressure is to rely on the valve operating torque can reach this. This kind of valve is to be operated by torque control. In actual practice, it may often cause the leakage when it is closed by electric. So for this aspect, it need to manually close the valve. In case of unforeseen circumstances, in order to ensure that the valve closed tightly, usually we need to use a long rod to force for closing it. This operating condition neither achieve the remote control and system automation, but also increased the operator's labor intensity and shorten the service life of valve. Because the valve is not closed tight, the medium of leakage will wash off the sealing surface in high-speed, it must be a apid damage of it. If we close the valve with a long rod, we can not control the torque and inevitably damage the sealing surface, such as high temperature electric gate valve and motorized triple offset butterfly valve etc. We can also call electric valve or motorized valve. It is the same type.

The electric valve can not close tightly, and people can manually shutting the valve. Obviously the problem is subject to the control system of electrical device.

At present, the electric valve is usually equipped with stroke control and torque control two sets of systems, it is built to travel for the control, and torque for the protection. For the stroke control valve, normal working hours, to travel to control valve fully open and fully closed position. If the travel is out of control, we need to use the manual torque protection for its operation which can be maintained to avoid valve damage. In order to ensure the safety valves and production systems. Torque control valve in the existing system, travel system can not afford protection role. Torque control failure or values ​​change, the valve operating torque will be increased rapidly in an instant, but no other protective measures. Therefore, this control system is not complete.

Even with the applicable control system, after the electric device and the valve assembly, is also accurate debugging and setting the control parameters. Generally, the electrical device at the factory, the rated output torque has been completed calibration. After calibration of torque, however, only indicates that the work capacity of electrical device, the torque is not the same as the valve closes. The valve closes the required torque in addition to the valve specification model, the actual work with the valve media, pressure and temperature, the user should re-adjustment and setting. However, most of valve users (including valve manufacturer) do not have the torque detection means, and can not be set torque value. And valve operation for some time after repair, the torque of electric device factory settings have been changed must be re-set. The case of lack of torque determination means, the valve user can only be adjusted in accordance with the valve fully open and fully closed position the valve opening direction, and set in the fully open and fully closed position limit switch action to ensure that the travel control can work properly. Then, the valve is closed, the trip off switch action based on, manual off valve, feel close torque increased to a certain range, adjust the action of torque switch. This set of results must be the valve opening and closing is still subject to the control of limit switch. The closing toruqe of valve can not be guaranteed, so the tightness of sealing is difficult to guarantee.

In many companies, valves and electrical installations are belong to two departments for managemen. Valve owned by the equipment sector management, and electric installations owned by the instrument sector management. Electric devices typically meter department responsible for adjusting the settings. Instrumentation sector natural focus in the control system work properly, as long as the stroke control adjustment, and automatic control of whole system will be able to work properly. As for the work to ensure that the valve closing moments do not get enough attention, often electric valve operation after the closure of leakage is simply regarded as the poor quality of valve. In fact, the electric valve closure is not tight and is caused by a variety of factors, both technical reasons, also organized management reasons. Only by taking a realistic and practical approach, one by one to solve these problems, in order to ensure that the valve performance.

In order to ensure the reliability of electric valve operation, valve commissioning training should be strengthened so that they can correctly grasp the reasonable debugging method for all kinds of valves. So that the electric valve closure tightness in the electric operation will be radically improved. The valve itself is good quality, the reliability of valve will be improved, and will also be welcomed by users.

A butterfly valve is a valve which can be used for isolating or regulating flow. The closing mechanism takes the form of a disk. Operation is similar to that of a ball valve, which allows for quick shut off. Butterfly valves are generally favored because they are lower in cost to other valve designs as well as being lighter in weight, meaning less support is required. The disc is positioned in the center of the pipe, passing through the disc is a rod connected to an actuator on the outside of the valve. Rotating the actuator turns the disc either parallel or perpendicular to the flow. Unlike a ball valve, the disc is always present within the flow, therefore a pressure drop is always induced in the flow, regardless of valve position.


A butterfly valve is from a family of valves called quarter-turn valves. The "butterfly" is a metal disc mounted on a rod. When the valve is closed, the disc is turned so that it completely blocks off the passageway. When the valve is fully open, the disc is rotated a quarter turn so that it allows an almost unrestricted passage of the fluid. The valve may also be opened incrementally to throttle flow.


There are different kinds of butterfly valves, each adapted for different pressures and different usage. The resilient butterfly valve, which uses the flexibility of rubber, has the lowest pressure rating. The high performance butterfly valve, used in slightly higher-pressure systems, features a slight offset in the way the disc is positioned, which increases the valve's sealing ability and decreases its tendency to wear. The valve best suited for high-pressure systems is the triple offset butterfly valve, which makes use of a metal seat,[clarification needed] and is therefore able to withstand a greater amount of pressure.

1. Structure
Butterfly valves are valves with a circular body and a rotary motion disk closure member which is pivotally supported by its stem. A butterfly valve can appear in various styles, including eccentric and high-performance valves. These are normally a type of valve that uses a flat plate to control the flow of water. As well as this, butterfly valves are used on firefighting apparatus and typically are used on larger lines, such as front and rear suction ports and tank to pump lines.


2. Types
Concentric butterfly valves - This type of valves has a resilient rubber seat with a metal disc.
Doubly-eccentric butterfly valves (high-performance butterfly valves or double-offset butterfly valves) - Different type of materials is used for seat and disc. Triply-eccentric butterfly valves (triple-offset butterfly valve) - The seats are either laminated or solid metal seat design.


3. Triply-eccentric (offset) design
Triple eccentric (offset) Design prevents galling and scratches between the metal seat and the metal disc due to its unique design. The only time where the seal comes into contact with the seat is at the point of complete closure. Triple offset valves are generally used in applications which require bi-directional tight shut-off in oil and gas, LNG/NPG terminal and tanks, chemical factories, and shipbuilding. Widely use for dirty/heavy oil to prevent extrusion.


4. Wafer-style butterfly valves
The wafer style butterfly valve is designed to maintain a seal against bi-directional pressure differential to prevent backflow in systems designed for unidirectional flow. It accomplishes this with a tightly fitting seal; i.e., gasket, o-ring, precision machined, and a flat valve face on the upstream and downstream sides of the valve.


5. Lug-style butterfly valve
Lug-style valves have threaded inserts at both sides of the valve body. This allows them to be installed into a system using two sets of bolts and no nuts. The valve is installed between two flanges using a separate set of bolts for each flange. This setup permits either side of the piping system to be disconnected without disturbing the other side.
A lug-style butterfly valve used in dead end service generally has a reduced pressure rating. For example a lug-style butterfly valve mounted between two flanges has a 150 psi pressure rating. The same valve mounted with one flange, in dead end service, has a 75 psi rating.

There are a lots of customers inquired from us. What can we supply? 
General speaking, we can manufacture industrial valves likely ball valve, butterfly valve, gate valve, check valve, globe valve and plug valve, we also supply valve parts likely valve ball, valve stem and so on. For special accessories valve fittings, we also supply such as valve screw, bolts, nuts, gearbox and pneumatic actuator.
If you have any enquires, please contact us! Our sales team will reply you within 24 hours.
Welco Valve - Flow Control Solution
You can contact us by telephone, post, online or E-mail.
Website: www.chinavalve.info 
Address: Sanqiao Industrial Zone, Oubei Town, Yongjia Country, Zhejiang Province, P.R. China
Postcode: 325102
Telephone: +86 577 57882881 / 57882882
Fax: +86 577 57889889 
E-mail: welcovalve@gmail.com 
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