Butterfly valves are typically installed in the following applications:

1. Pipelines: Butterfly valves are commonly used in pipelines for the control and regulation of fluid flow, such as in water, gas,  butterfly valve factory  and chemical distribution systems.

2. HVAC systems: Butterfly valves are widely used in heating, ventilation, and air conditioning (HVAC) systems to control the flow of air or other gases.

3. Industrial processes: Butterfly valves are employed in various industrial processes, such as in the pulp and paper industry, power generation plants, and manufacturing facilities, to manage the flow of fluids, slurries, and other materials.

4. Water and wastewater treatment: Butterfly valves are utilized in water and wastewater treatment plants for flow control and isolation purposes.

5. Marine applications: Butterfly valves are found in marine environments,  China butterfly valve suppliers  such as on ships and offshore platforms, to control the flow of water and other fluids.

6. Building services: Butterfly valves are used in building services, like plumbing and fire protection systems, to regulate the flow of water or other fluids.

The compact design, ease of installation, and ability to provide reliable flow control make butterfly valves a popular choice in a wide range of industries and applications where quick and efficient flow regulation is required.