What type of pipe is characterized as flexible and utilizes insert fittings?

Polyethylene pipe is characterized as flexible and makes use of insert fittings. This type of pipe is commonly used in irrigation systems due to its ability to bend and navigate around obstacles, making it ideal for various landscaping and agricultural applications. The flexibility of polyethylene allows for ease of installation and reduces the need for rigid fittings, which can be more difficult to work with in certain terrains or layouts.

Insert fittings are specifically designed to connect polyethylene pipe securely without the need for additional tools or complicated joining techniques. This connection method is effective in creating a watertight seal, which is crucial for maintaining the efficiency of irrigation systems. Additionally, polyethylene pipe is lightweight and often resistant to corrosion, further enhancing its suitability for outdoor water transport.

Other types of pipes, such as metal, PVC, and ABS, do not share these same characteristics of flexibility and compatibility with insert fittings, making polyethylene the best fit for the described qualities.