Brass plumbing fittings are versatile components that can be used in a wide range of plumbing applications due to their durability, corrosion resistance, and malleability. The suitability of brass plumbing fittings for different applications depends on several factors, including the type of brass alloy used, the specific fitting design, and the conditions of the plumbing system. Here are some common applications where brass plumbing fittings are often used:

1. Residential Plumbing: Brass fittings are commonly used in residential plumbing systems for both hot and cold water supply lines. They are suitable for connecting pipes, fixtures, and appliances, such as sinks, toilets, showers, and washing machines.

2. Commercial Plumbing: Brass fittings are also widely used in commercial plumbing systems, including in restaurants, hotels, office buildings, and retail establishments. They are suitable for various water supply and drainage applications.

3. Potable Water Systems: Brass fittings are an excellent choice for potable (drinking) water systems due to their low lead content and corrosion resistance. They help maintain water quality and safety in homes and businesses.

4. Heating Systems: Brass fittings are used in heating systems, including radiators, boilers, and baseboard heaters. They can handle the high temperatures and pressures associated with these systems.

5. Cooling Systems: Brass fittings are suitable for cooling systems in HVAC (heating, ventilation, and air conditioning) applications, including for connecting pipes and components in air conditioning units and chillers.

6. Natural Gas and Propane Lines: Brass fittings are compatible with natural gas and propane systems. They are used for connecting gas lines, valves, and appliances such as stoves and water heaters.

7. Fire Sprinkler Systems: Brass fittings are used in fire sprinkler systems to connect pipes and components. They are suitable for both wet and dry fire suppression systems.

8. Industrial Applications: Brass fittings are employed in various industrial settings, including manufacturing facilities and chemical plants. They can handle a range of chemicals and are used for conveying fluids and gases in industrial processes.

9. Automotive and Marine Applications: Brass fittings are used in automotive and marine plumbing systems for applications such as fuel lines, coolant systems, and hydraulic lines.

10. Steam Systems: Brass fittings are suitable for low-pressure steam systems commonly found in some industrial processes and heating applications.

11. Agricultural and Irrigation Systems: Brass fittings are used in agricultural and irrigation systems to connect pipes and hoses for watering crops and landscapes.

12. Pneumatic Systems: Brass fittings are used in pneumatic systems for controlling the flow of compressed air in manufacturing and automation applications.

13. Hydraulic Systems: In low-pressure hydraulic systems, brass fittings can be used to connect hydraulic lines and components.

It's important to note that the suitability of brass fittings for a specific application may depend on factors such as the type of brass alloy, the size and design of the fittings, and the local plumbing codes and regulations. Before selecting and installing brass fittings, it's advisable to consult with a plumbing professional or refer to relevant industry standards to ensure they meet the requirements of the specific application.