The piping from a transfer pump to equipment at levels above the lowest floor or storage tanks at levels above the lowest floor in buildings, the return piping, and vent piping shall be enclosed in a shaft constructed of 4-inch (102 mm) concrete or masonry having a 4-inch (102 mm) clearance from all pipe or pipe covering, except that no such enclosures shall be required within the room containing the pump, tank, or equipment where such room is itself enclosed with construction and materials having at least a 2-hour fire-resistance rating. Multiple fuel oil risers serving multiple systems are permitted within a common shaft enclosure. All shaft penetrations must be fire stopped.
Where it is necessary to make horizontal offsets in the supply and overflow/return piping and pipe shafts, including the lowest level, such piping shall be enclosed in a sleeve of other piping of at least No. 10 standard Gage steel, two sizes larger than the supply piping and arranged to drain into the shaft. Horizontal piping offsets shall be further enclosed in construction having a 2-hour fire-resistance rating except that no such enclosure or pipe sleeve shall be required for the pipes serving the equipment within the room containing the pump, tank, or equipment where such room is itself enclosed with construction and materials having at least a 2-hour fire-resistance rating. Horizontal piping shall include all piping at or above the roof level. No 2-hour fire-resistance-rated enclosure is required for horizontal piping offsets located outside the building.
A drain pipe shall be installed at the base of shafts enclosing the supply and overflow/return piping. The pipe shall lead to a dedicated sump or minimum 55-gallon (208 L) container with a leak detection alarm, arranged so as to sound an alarm and stop the transfer pump. The alarm shall be connected to a local audible alarm and to a remote alarm located at a supervising station. The wiring shall comply with the New York City Electrical Code.
Provision shall be made for expansion in piping without the use of expansion joints.
Pipe connections to the main header (supply or return) shall be made from the top of the header, except for systems with equipment above the lowest floor where such equipment is designed to operate utilizing fuel pumped as needed from the lowest floor and without utilizing fuel oil stored above the lowest floor.
Required air vents and vacuum breakers shall be designed for their required use.
In systems with equipment above the lowest floor where such equipment is designed to operate utilizing fuel stored above the lowest floor, piping diameters shall not exceed 4 inches (102 mm). However, where an applicant demonstrates by the inclusion of calculations in the construction documents that a greater diameter is necessary to ensure the proper flow for the functioning of the system, such greater diameter may be permitted. Piping shall not be used for fuel storage purposes.
In systems with equipment above the lowest floor, where such equipment is designed to operate utilizing fuel pumped as needed from the lowest floor and without utilizing fuel oil stored above the lowest floor, piping diameters throughout such systems shall not exceed the design flow (three times the maximum firing rate as calculated by the engineer or architect). However, piping diameters within rooms containing such equipment may exceed the calculated design flow pipe size to provide limited reservoir storage to prime equipment, provided such reservoir storage is counted toward the maximum permitted oil storage per story, as provided for in Section 1305.11.1.3.