PTD343H Triple Eccentric Hard Seal Butterfly Valve

Zhejiang Putian Triple Eccentric Butterfly Valve can be selected for dual-position regulation, constricted channels, low noise, cavitation and vaporization phenomena, slight atmospheric leakage, and abrasive media.

Under special working conditions such as throttling regulation, strict sealing requirements, severe wear, or low temperature (cryogenic) environments, a specially designed triple or double eccentric butterfly valve with a metal sealing strip adjustment device is required.

Zhejiang Putian Triple Eccentric Butterfly Valve is suitable for applications requiring complete sealing, zero gas test leakage, high lifespan, and operating temperatures between -10°C and 150°C. It is used in freshwater, sewage, seawater, saline water, steam, natural gas, food, oil, and various acid and alkali pipelines.

Zhejiang Putian Soft Seal Eccentric Butterfly Valve is suitable for bidirectional opening and closing as well as regulation in ventilation and dust removal pipelines. It is widely used in gas pipelines and water channels in metallurgy, light industry, electric power, and petrochemical systems.

Zhejiang Putian Triple Eccentric Metal-to-Metal Line Seal Double Eccentric Butterfly Valve is suitable for urban heating, gas supply, water supply, and other pipelines carrying gas, oil, acids, and alkalis, serving as a regulating and throttling device.

Zhejiang Putian Triple Eccentric Metal-to-Metal Face Seal Triple Eccentric Butterfly Valve, in addition to being used as a program control valve in large-scale pressure swing adsorption (PSA) gas separation devices, is widely used in petroleum, petrochemical, chemical, metallurgical, and electric power industries.

Working Principle of Zhejiang Putian Triple Eccentric Metal Hard Seal Butterfly Valve: A typical triple eccentric metal seal butterfly valve features two eccentrics on the valve stem and disc, with the sealing surfaces of the disc and seat forming an inclined truncated cone shape (the third eccentricity). When the valve closes, the disc is pushed forward due to eccentricity, avoiding friction between the disc and seat during closure. The disc directly presses against the seat, ensuring the valve's longevity.

Additionally, the sealing ring of Zhejiang Putian valves (whether mounted on the seat or disc) has a certain elasticity, and a small gap between the inner protrusion and the elastic ring allows slight displacement. During closure, the elastic sealing ring automatically moves to a uniformly stressed position under closing force. Combined with slight deformation of the elastic ring, the sealing ring at the seat achieves uniform stress and sealing.

Performance Changes of Triple Eccentric Metal Hard Seal Butterfly Valves with Different Eccentric Structures: Traditionally, butterfly valves were considered suitable only for常温, low-pressure, and low-sealing-requirement applications.

With advancements in modern technology and materials, Zhejiang Putian butterfly valves are now used far beyond their traditional scope, replacing most conventional valves and widely applied across various industries. The triple eccentric metal seal butterfly valve is particularly noteworthy.

Since the closure of a triple eccentric butterfly valve, like a gate valve, is torque-driven, higher closing torque results in better seat sealing. Hence, it is sometimes called a 90° rotating gate valve. In major factory overhauls, triple eccentric butterfly valves increasingly replace gate valves. Some manufacturers produce triple eccentric butterfly valves with the same length as gate valves, dubbing them triple eccentric gate valves.

As the number of eccentrics in Zhejiang Putian valves increases, the disc thickness also increases, raising fluid flow resistance. Performance changes significantly with the number of eccentrics.

Comparison of four different butterfly valve structures shows that triple eccentric butterfly valves can generate significant pressure drops, making them suitable as control valves. Pressure drop across the valve increases with the number of eccentrics but remains relatively low compared to non-butterfly valves. Seat sealing performance varies with eccentricity, with triple eccentric valves offering superior sealing. Increased eccentricity reduces the torque required for opening and closing, making triple eccentric valves much easier to operate than other types.

Changes in eccentricity also affect the temperature-pressure rating and applicable temperature range. Triple eccentric butterfly valves have broader temperature and pressure ratings compared to other types.

Advantages of Triple Eccentric Butterfly Valves: Excellent shut-off performance. The triple eccentric metal seal butterfly valve uses torque to achieve closure, ensuring superior seat sealing and earning it the name "zero leakage valve." Solid particles or contaminants in the medium have minimal impact on shut-off performance because high fluid velocity near closure prevents accumulation at the seat.

Features of Metal Hard Seal Butterfly Valves:

1. The disc sealing ring of Zhejiang Putian triple eccentric multi-layer metal hard seal butterfly valves consists of laminated soft and hard metal sheets, combining the advantages of metal and elastic sealing. It offers excellent sealing performance at both low and high temperatures.

2. Bushings are installed at the upper and lower parts of the valve stem, with minimal wear and friction resistance. This design prevents wear and sticking, extending service life.

3. The three-dimensional eccentric structure minimizes friction between the seat and disc, preventing internal damage during closure. It enhances valve performance and provides a tighter seal with increased closure.

4. The valve body sealing surface is welded with alloy steel or Stellite hard alloy, offering wear, erosion, and corrosion resistance, ensuring long service life.

5. Compact structure with low switching torque, flexible, labor-saving, and convenient operation. Sealing performance is reliable regardless of medium pressure, making it suitable for both shut-off and regulation.

Eccentricity 1: The valve axis is located behind the seat axis, ensuring complete and tight sealing around the entire seat.

Eccentricity 2: The valve axis is offset from the pipeline and valve centerline, avoiding interference during opening and closing.

Eccentricity 3: The seat cone axis is offset from the valve axis, eliminating friction during opening and closing and achieving uniform compression sealing around the entire seat.