Which type of pipe is best for applications involving relatively low water pressure?

Schedule 40 pipe is considered the best option for applications involving relatively low water pressure due to its balance of strength, weight, and cost-effectiveness. Schedule 40 pipes have a moderate wall thickness, which provides adequate pressure handling capabilities while remaining lightweight and easy to handle. This makes them ideal for residential and light commercial plumbing applications, where the pressures involved are typically not extreme.

In contrast, other types of pipe, such as Schedule 20, have thinner walls and are generally suitable for lower pressure scenarios but may not offer the durability needed for broader applications. Schedules 80 and 100 pipes, with their thicker walls, are designed for high-pressure situations, which makes them unnecessarily heavy and expensive for applications where pressure is not a concern. Therefore, Schedule 40 represents an optimal choice for handling low pressure effectively while being economical and versatile.