Credit: Photo: CONTECH Construction Products Inc.

Depending on the application and material, pipes can be a few inches in diameter, or big enough to drive a truck through. The flexibility and lightweight of corrugated PVC pipe contributes to its ease of handling.

Credit: Photo: American Cast Iron Pipe Co.

Ductile iron pipe is commonly specified for water and wastewater applications, as in this installation of 42-inch-diameter pipe.

It would be nice if specifying pipe were as simple as buying a pair of shoes—walk into a store to pick out the style you like and take it home.

Unfortunately, there are a lot more questions to answer in choosing pipe than picking the perfect pair of loafers. What's going to be running through the pipe? In what kind of climate and terrain will it operate? What local codes factor in? What's the budget? Luckily, the pipe industry and associations offer resources to guide you.

The decision-maker in public works pipe installations is usually an engineer within the agency or an outside consultant. This person must look at:

Application: Determine whether the pipe will be used to carry drinking water, transport sewage, drain stormwater, or serve some other purpose.

Cost: Budget constraints—a constant concern for all public works departments—may put one or more types of pipe out of reach, or motivate the specifier to make choices with an emphasis on reducing maintenance and extending pipe life.

Demands: The heaviness of the load placed on a pipe—how much sewage, wastewater, potable water, or other effluent passes through it in a given time period—will affect the installation's needed attributes, including hydraulic capacity.

Environmental conditions: An area's climate, soil conditions, vegetation, population, and other factors all contribute to the external demands placed on installed pipe.

Material: Each type of pipe available offers unique properties and installation requirements that makes it more suitable for some applications than for others. For example, concrete pipe's structural durability makes it more resistant to collapse than other materials, corrugated steel offers flexibility and strength, vitrified clay pipe is corrosion-resistant, high-density polyethylene (HDPE) is lightweight.