Which material is required for above ground fill and vent piping?

The requirement for above ground fill and vent piping is based on the need for durability, strength, and resistance to various conditions such as pressure and environmental factors. Schedule 40 steel is a reliable choice for this purpose because it offers adequate wall thickness to withstand the pressures typically experienced in oil fuel systems while also being robust enough to handle potential impacts and environmental exposure without degrading.

Additionally, steel piping is less susceptible to damage from external forces and environmental degradation compared to other materials. Steel also has a proven track record in fuel piping applications, ensuring that it can effectively handle the necessary operational demands without compromising safety or functionality.

Other materials listed, while they may have specific applications, do not meet the same criteria as Schedule 40 steel for this particular use case. The options that involve plastic, brass, or copper may not provide the same level of structural integrity, especially in pressure situations or where physical protections against impacts and environmental influences are necessary. This makes Schedule 40 steel the most suitable option for above ground fill and vent piping in the context of the Maine Journeyman Oil Fuel Board standards.