YQA 25 Fuel Systems in High Rise Buildings
25.1 Where are tanks located in buildings?
Tanks are required by code to be located in buildings at the lowest level in the building, with limited volumes allowed for day tanks in upper levels. This means that tanks are often located several level below ground in urban high rise construction, while generators may be locate at grade, upper floors , or the roof.. The tanks are filled by delivery trucks located at grade. So between fill piping, fuel supply and return piping to generators, and tank vent piping, routing of fuel piping within buildings is an important consideration.
25.2 What are day tank restrictions on upper floors?
Day tank restrictions on upper floors vary with local building codes. Common limits are 240 gallons limit for a floor or room, or sometimes the much more restrictive 60 gallons.
25.3 How is piping designed for building risers?
Between fill piping, fuel supply and return piping to generators, and tank vent piping, routing of fuel piping within buildings is an important consideration. Most of the piping is routed vertically through risers, and layout and coordination with other building systems is an important consideration. Fuel oil supply, return, and vent piping is typically double wall steel pipe with welded connections. Tank vent pipe is typically single wall piping. Tank vent piping is an important consideration for fuel systems in buildings. In some locations emergency vents are required to be routed to the exterior of the building. For a double wall tank, this would be 2 pipes from 4” to 10” diameter. Added to fuel oil supply, return, and normal vent piping, this can be a considerable installation cost, and also take up a lot of space within the building.
25.4 What is a fuel header system?
A fuel header system is designed to provide fuel to multiple generators, where there are severe regulatory restrictions to the volume of fuel that can be stored in the generator room. The header is an 8” to 12” diameter pipe which runs the length of the room to serve all generators. The pipe is sized to be less than the regulatory limit for fuel storage quantities in the room.
The generators draw fuel from the header pipe, and return fuel to the header pipe. The fuel supply pumps draw fuel from a bulk tank and pump to the header inlet. The header outlet is a gravity overflow back to the bulk storage tank.