Which types of pipes are required for hood systems?

Hood systems, particularly in commercial kitchens, are designed to handle high temperatures and the byproducts of cooking processes, such as smoke, grease, and heat. To ensure adequate performance and safety, certain materials are prescribed for these systems.

The correct answer highlights the use of black pipe, stainless steel, and chrome sleeving, which are preferred materials for duct systems associated with kitchen hoods. Black pipe is durable, resistant to high temperatures, and can handle the type of environment typically found in kitchens. Stainless steel is particularly valued for its corrosion resistance, strength, and ability to withstand heat, making it ideal for exhaust ducts and hoods. Chrome sleeving adds a layer of protection and enhances the appearance while assisting in maintaining the integrity of the system.

Other materials mentioned in the other choices, such as plastic or PVC, are not suitable for hood systems due to their inability to withstand high heat and potential exposure to grease, which could lead to failures or fire hazards. Only the materials specified in the correct answer meet the fire safety and practical applicability requirements necessary for effective hood system operation in commercial cooking environments.