YQA Fuel Piping Material Selection

14.02 What are common pipe materials?

The primary underground pipe materials are:

  • Fiberglass piping – primary and secondary
  • Flexible double wall plastic piping
  • Steel primary piping with a fiberglass or coated steel containment

The primary aboveground pipe materials are

  • Schedule 40 carbon steel pipe for primary
  • Schedule 10 carbon steel pipe for secondary

There is a PVC secondary containment pipe that is approved for inside building applications in some jurisdictions.

14.01 Where is double wall piping required?

Double wall piping is required by nearly all regulations for underground fuel piping. Aboveground piping is often required to be double contained by State and local regulations – however, requirements vary widely. NFPA 30 requirements for piping allow for single wall piping, however, piping within walls or otherwise inaccessible needs to have welded pipe joints.

In practice, most technical building have double wall piping within buildings for all piping that can contain fuel. Vent piping is typically single wall.