Welding type three eccentric hard seal butterfly valve

Overview purpose

The three eccentric metal sealed flange butterfly valve series is a long-life and energy-saving butterfly valve. Its structure is designed based on the three-dimensional eccentric principle, and the valve seat adopts a multi-level structure or all metal sealing structure that is compatible with hard and soft seals. It is a high-performance butterfly valve product that can be used in high temperature and high pressure environments. This product is widely used in pipelines for corrosive media such as metallurgy, steel, electricity, petroleum, chemical, heating, air, gas, combustible gases, municipal water supply, and drainage, as a cut-off or regulating medium flow rate. As a crystallization of new valve technology, the three eccentric butterfly valve highlights the strengths of various valves and avoids their weaknesses. It can correspond to various structural lengths such as clamps, lugs, flanges, ring joints, butt welds, and jackets. Due to the wide range of material choices, it can also adapt to high and low temperatures as well as various corrosive media such as acids and alkalis. Especially in terms of large diameters, with its zero leakage advantage, it is constantly replacing bulky gate valves and ball valves in shut-off valves; Similarly, its excellent regulatory function is constantly replacing bulky globe valves in regulating valves.

Main features of the product

High performance 3D eccentric sealing system
-For laminated valve rings: bi-directional zero leakage seal (according to German standard level 1 or American standard level VI)
-For integral valve rings: bi-directional tight seal (according to American standard V level)

1. Excellent gas and liquid isolation function and flow regulation characteristics
2. Weld in stainless steel or weld on Stellite hard alloy valve seats are particularly suitable for long-life use
3. The valve seat opens and closes without friction, wear, or jamming (only tight pressure)
4. Sealing rings that are easy to replace and adjust for sealing performance
5. Suitable for harsh working conditions such as high temperature, high pressure, and corrosive environments
6. Metal/metal hard seal that can reach up to+600 ℃
7. Self compensating process for temperature changes
8. Low operating torque and reliable torque shutdown
9. Fundamental fire safety design
10. Butterfly plate seal, uniformly compressed along the circumference, produces a welding like effect, causing the sealing ring to bend and act like a spring. Elastic sealing ensures compliance with API 598- Elastic Seat Standard for liquids or gases. The elasticity of the seal enables the butterfly plate to maintain a closed and airtight seal during thermal cycling as shown in the figure.

The principle of three eccentricities

The eccentric 1 valve shaft is located behind the valve seat shaft, allowing the seal to completely and tightly wrap around the entire valve seat.
The centerline of the eccentric valve shaft deviates from the centerline of the pipeline and valve, which avoids interference from valve opening and closing.
The eccentric 3 valve seat cone axis deviates from the centerline of the valve shaft, which can eliminate friction during the closing and opening process and achieve a uniform and consistent compression sealing effect around the entire valve seat.

structural characteristics

The torque generated during the sealing closure of the laminated butterfly plate generates valve seat force, which uniformly and uniformly acts around the entire circumference. The elastic seal bends and is full of vitality, maintaining the shape of the valve seat. The compressive force acts uniformly along the circumference, enabling the valve to achieve bi-directional tight closure. The elasticity of the seal allows the valve body and butterfly plate to come into contact or expand, avoiding the risk of blockage caused by temperature fluctuations. This device is capable of self adjusting alignment.

The diversity of sealing structures can adapt to different needs

1. Conventional type: Multi layer sealing rings are fixed on the butterfly plate, easy to replace and adjust, with reliable sealing, suitable for most occasions.
2. Body sealing structure: The sealing ring is fixed on the valve body, and during the opening process, the sealing ring does not move with the butterfly plate, so it is not easily damaged; In the case of a short structural length, due to the increased thickness of the butterfly plate in the plate sealing structure, it is easy to exceed the valve body, making it more suitable to use a body seal.
3. Removable valve seat type: Both the body and plate seat can be replaced, making maintenance and replacement easier and reducing maintenance costs.

Butterfly plate sealing ring

The layered elastic butterfly plate sealing ring can withstand a high temperature of 538 ° C. Assemble one to six flexible graphite plates in the interlayer between thin stainless steel rings. The flexible graphite sealing ring and stainless steel ring are not bonded with glue, so they can withstand higher temperatures.

Components and Materials

1. Valve explosion diagram

2. Basic configuration of parts and materials

Model designation example

execution standard

Scope of Application

Nominal diameter: 2 "~160" (DN50~4000)
公称压力： 150LB ~ 600LB (PN10~100)
Temperature range: -180 ° C~700 ° C
Connection methods: clamp type, lug type, flange type, butt welding type
Applicable media: freshwater, seawater, sewage, air, steam, food, medicine, oil and various
Seed oil, acid, alkali, salt with weak corrosive media, etc