There are differences between clamp type butterfly valves and flange type butterfly valves in terms of connection methods, structural characteristics, installation and maintenance, sealing performance, applicable scenarios, cost and price. The following is a detailed introduction:

Connection method

Clamp on butterfly valve: There are no flanges at both ends of the valve body, only a few guide bolt holes. The valve is clamped between the two pipeline flanges with double headed bolts, and the sealing is achieved by using the clamping force of the clamp flange and the sealing ring.

Flange butterfly valve: The valve is equipped with flanges at both ends, which are connected to the pipeline flange through bolts, and sealed with gaskets or rubber rings in the middle.

Structural characteristics

Clamp type butterfly valve: simple and compact structure, no additional flange structure, light overall weight, small volume, and relatively few components.

Flange butterfly valve: Due to the flange connection, more bolts are required at the connection point, and the flange itself has a certain thickness and size, so the overall structural length is generally longer than that of the clamp butterfly valve, and the weight is relatively heavier.

Installation and maintenance

Clamp type butterfly valve: During installation, simply clamp the valve between the pipeline flanges and tighten it with bolts. The installation is relatively simple and fast, and the structure is compact, occupying little space. However, when the valve needs to be repaired or replaced, due to its reliance on pipeline flange compression connection, if one sealing surface has a problem, it often requires disassembling two pipeline flanges for maintenance.

Flange butterfly valve: During installation, a separate flange needs to be set on the pipeline, and multiple bolts need to be unscrewed during installation and disassembly, which is relatively cumbersome and requires a large installation space. But during maintenance, if it is a problem with the valve itself, only the flange bolts at both ends of the valve need to be removed, without dismantling the pipeline flange, which facilitates the inspection and replacement of the valve.

Sealing performance

Clamp type butterfly valve: The pressure between the valve plate and the valve seat is mainly transmitted through the elastic sealing rings on both sides, and its sealing performance is relatively good. The wedge-shaped design enables the valve to have an automatic sealing function that becomes tighter as it is closed, usually achieving a good sealing effect.

Flange butterfly valve: The sealing performance mainly depends on the tightness of the flange connection, the quality of the sealing gasket, and the sealing structure of the valve itself. If installed correctly and the sealing gasket is intact, good sealing can be achieved, but it may be affected by factors such as installation accuracy, medium pressure, and temperature.

Applicable scenarios

Clamp type butterfly valve: suitable for general medium and low pressure and small-diameter pipeline systems, such as building water supply and drainage systems, air conditioning systems, general industrial pipelines, etc., with good economy and practicality.

Flange butterfly valve: suitable for high temperature, high pressure, and large-diameter pipeline systems, capable of withstanding large pressures and torques, with stable and reliable connections. For example, it is commonly used in high-temperature and high-pressure steam pipelines of large chemical plants and thermal power plants.

Cost and Price

Clamp on butterfly valve: With a simple structure, relatively few components, and lower manufacturing costs, it is usually cheaper than flange butterfly valves, usually around 2/3 of the price of flange butterfly valves.

Flange butterfly valve: Due to its relatively complex structure, it requires more materials and processing techniques to manufacture components such as flanges, resulting in higher costs and relatively expensive prices.