Introduction to cast iron lug-type butterfly valves

Definition and working principle

The cast iron lug-type butterfly valve is a type of butterfly valve. A butterfly valve is a kind of valve that uses a disc-shaped opening and closing element to reciprocally rotate about 90° to open, close or regulate the flow of the medium. Its closing element (valve flap or butterfly plate) is a disc. The butterfly plate rotates around the valve shaft to achieve opening and closing, and it is installed in the diameter direction of the pipeline.

Product specifications

Caliber

The caliber of Taiwan 317 cast iron lug-type butterfly valves ranges from DN10 to 100mm; the specifications of Bande LT71F – 16Q lug-type fluorine-lined wafer butterfly valves (cast iron wafer-type lug butterfly valves) include DN50, DN65, DN80, DN100, DN125, DN150, DN200, etc.; the product caliber of the lug wafer-type butterfly valve with product model Dt373H ranges from DN50 to DN1000; the caliber range of wafer-type butterfly valves is from DN50 to DN350.

Pressure

The pressure of Taiwan 317 cast iron lug-type butterfly valves is 1.6 – 6.4 Mpa, the working pressure is 10 kg/cm² (150 PSI), and the test pressures (ISO – 5208) are 20 kg/cm² (300 PSI), 24 kg/cm² (340 PSI), etc. The product pressure of the lug wafer-type butterfly valve with the product model Dt373H is 0.6 – 2.5 MPa. The pressure range of the lug-type butterfly valve is PN0.1 – 10 M.

Structural characteristics

• Three-way eccentric design: The unique three-way eccentric design enables frictionless transmission between the sealing surfaces, which can extend the service life of the valve. Moreover, the ingenious wedge design gives the valve an automatic sealing function that makes it seal tighter as it closes.

• Elastic seal: The elastic seal is generated by torque. The gasket is made of spirally coiled stainless steel/graphite to achieve zero leakage. The torque during closing generates the seat force, which acts uniformly around the entire circumference. The elastic seal bends and is full of vitality, maintaining the shape of the seat. The compressive force acts uniformly along the circumference, enabling the valve to achieve tight two – way closing. Its elasticity allows the valve body and disc to contact or expand, avoiding the risk of blockage due to temperature fluctuations. This device can also self – adjust the alignment.

Applicable media

The Taiwan 317 cast iron lug-type butterfly valve is suitable for water, seawater, sewage, air, oil, powder, gas, etc.; the Bande LT71F – 16Q lug-type fluorine-lined wafer butterfly valve is suitable for weak acid and alkali media, various highly corrosive chemical media, water, air, corrosive media, etc.; the lug-type butterfly valve and the ear-supported butterfly valve are applicable to media such as water, air, food, and oil products.

Driving and connection methods

Driving mode

The driving modes of lug-type butterfly valves can be manually operated, worm gear driven, pneumatically driven, or electrically driven.

Connection method

The connection methods can choose flange or wafer.

Brand and Market

Brand-related

There are multiple brands of cast iron lug butterfly valves in the market, such as Taiwan 317, Acckes from Germany, LIT, NIBCO, Bando, Best, etc. Among them, Acckes International Group from Germany launched an independent subsidiary – Shanghai Acckes Valve Co., Ltd. in Shanghai, China in 2008, and established a branch – Acckes Valve Co., Ltd. in Hong Kong, China in 2009, and set up a complete after – sales service center and logistics distribution center in China. Bando Valve was established on August 5, 1994, with a registered capital of 102.3 million yuan. Its factory is located at No. 37, Puhui Road, Beizhakou Economic Development Zone, Jinnan District, Tianjin, specializing in the production and supply of valve products of various models.

Market application

Cast iron lug-type butterfly valves can be applied in multiple fields. The users of German EX products cover fields such as petroleum, chemical industry, electric power, metallurgy, pharmacy, food, water treatment, municipal water supply and drainage, natural gas, papermaking, electronics industry, buildings, and supporting of mechanical equipment. Its business in China is mainly concentrated on high-tech applications in nuclear power plants, chemical petroleum, marine vessels, gaseous fuels, water treatment, and commercial buildings. Bando Valves’ products are widely used in industries such as water treatment, heating, ventilation, municipal engineering, water supply and drainage, petroleum, and chemical industry. Best marine lug-type butterfly valves are mainly used in ship pipelines, and mainly play the roles of cutting off and throttling in the pipelines.