§ 27-830 Piping.
(a) Installation of piping and tubing.
(1) Exposed piping shall be protected against mechanical damage and shall be adequately supported with rigid metal fasteners or hangers. All pipes connected to buried tanks, except test well piping, shall be provided with double swing joints at the tank.
(2) Only new wrought iron, steel, or brass pipe, or type K or heavier copper tubing, or aluminum alloy tubing, properly identified, may be used. Metal tubing when used for conveying oil shall be adequately protected. Such tubing may be installed at the burner without protection. Drawn tubing when used in domes- tic installations shall be of at least 3/8 in. inside diameter up to the shut-off valve at the burner. Soldered connections shall be prohibited.
(3) Overflow pipes, where installed, shall not be smaller in size than the supply pipe.
(b) Relief valves.
(1) Where a shut-off valve is installed in the discharge line from an oil pump, a relief valve shall be installed in the discharge line between the pump and the first shut-off valve.
(2) A relief or pressure regulating valve shall be provided in the oil piping system on the heater side of the shut-off valves.
(3) Relief valves shall be set to discharge at not more than one and one-half times the maximum working pressure of the system. The discharge from relief valves shall be returned to the storage tank or to the supply line. There shall be no shut-off valve in the line of relief.
(c) Fuel oil heaters. Fuel oil heaters shall not be installed within the steam or water space of a boiler. Fuel oil heaters and the connecting piping shall be arranged to prevent oil leakage from being transmitted to the boiler. This may be accomplished by any of the following methods:
(1) By discarding the condensate from the heaters.
(2) By using approved double tube or other approved heaters.
(3) By means of a secondary hot water or steam heating system where the water or steam from the boiler has no direct contact with the oil heater.
(4) By a sight tank arrangement for collecting and inspecting the condensate which is provided with a pump controlled by a hand switch for returning the condensate to the normal return system.
(5) By such other method as may be permitted by the commissioner.
(d) Vent pipe.
(1) A vent pipe of iron or steel, without trap, draining to the tank, shall be provided for each storage tank. The lower end of the vent pipe shall not extend more than one inch through the top of the storage tank. Cross-connection between a vent pipe and fill pipe is prohibited.
(2) Where a battery of storage tanks designed to hold the same grade of oil is installed, vent pipes may be run into a main header.
(3) Vents shall be at least one and one-quarter inches in diameter for storage tanks not exceeding eleven hundred gallons capacity and at least two inches in diameter for storage tanks of eleven hundred gallons or more except that vents for storage tanks of sixty gallon capacity or less shall be at least one-half inch in diameter. Vents for tanks inside of buildings above the lowest floor shall be run into the primary storage tank vent.
(4) Vent pipes shall be provided with an approved weatherproof hood having a free area of at least the pipe size area. Vent pipes shall terminate outside the building in a nonhazardous location, at least two feet from any building opening and not less than two feet nor more than twelve feet above the fill pipe terminal, unless otherwise permitted by the commissioner. If the vent pipe terminal is not visible from the fill pipe terminal location, a one inch tell-tale line shall be connected to the tank and shall parallel the fill pipe and terminate at the fill pipe terminal with an unthreaded end. Such tell-tale lines shall be provided with a check valve set to prevent flow of surface water to the storage tank.
(e) Fill pipes.
(1) Fill pipes shall terminate outside the buildings, with the fill pipe terminal located at or above grade, at least two feet from any building opening and five feet from any subway grating at or below the level of the fill pipe terminal. No fill pipe shall be less than two inches in diameter, and no fill pipe for no. 6 oil shall be less than three inch in diameter. Where no. 6 oil is used, the fill pipe terminal shall be located within three feet of the curb, unless otherwise required by the department of transportation or the transit authority. Where there are facilities for the delivery tank truck to drive onto the premises, the fill terminal may be located elsewhere than at the curb, provided that the location complies with the other requirements of this subchapter.
(2) Each storage tank shall be provided with a separate fill pipe, except that where a battery of tanks is installed containing the same grade of oil, a common fill and header pipe may be installed.
(3) Where the top of the storage tank is above the fill pipe terminal, the fill pipe shall be connected to the top of the tank and provided with a shut-off valve and swing check valve both of which shall be located at the fill pipe terminal. However, the shut-off and check valves may be installed in an accessible location inside the building at or below the level of the fill pipe terminal.
(4) All fill pipe terminals shall be of an approved type, and shall be provided with lugs for embedding in concrete. In lieu of lugs, a set screw or threads to fasten the terminal to the fill pipe may be used. The outer flange of the fill pipe terminal or the seal cap shall be permanently marked "fuel oil". The fill pipe terminal shall be threaded or provided with other equivalent means to receive the seal cap. The seal cap shall be suitably slotted for receiving an opening wrench, and an oilproof gasket inserted in a groove in the fill pipe terminal shall be provided so as to make the seal cap leakproof. A strainer shall not be required but, if used, shall be of at least one-eighth inch mesh. Where a storage system for volatile flammable oil and a storage system for fuel oil are to be used in the same premises, the terminal of the fuel oil pipe shall be provided with a left-handed thread and the fill pipe fitting shall be of a different size than that required for the fill pipes to the tanks containing the volatile flammable oil.
(f) Piping from transfer pump to equipment or to storage tanks above the lowest floor.
(1) The piping from a transfer pump to equipment at levels above the lowest floor or to storage tanks at levels above the lowest floor in buildings, the return piping, and vent piping shall comply with the applicable provisions of subdivisions (a) and (d) of this section and shall be enclosed in a shaft constructed of four inch concrete or masonry having a four inch 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 two hour fire resistance rating. Provision shall be made for expansion in piping without the use of expansion joints.
(2) Where it is necessary to make horizontal offsets in the supply piping and pipe shafts such piping shall be enclosed in a sleeve of other piping of at least no. 10 U.S. standard gauge steel, two sizes larger and arranged to drain into the shaft. Horizontal piping offsets shall be further enclosed in construction having a two hour fire resistance rating, except that no such enclosure or pipe sleeve shall be required within the room containing the pump, tank, or equipment where such room is itself enclosed with construction and materials having at lease a two hour fire resistance rating.
(3) A drain pipe shall be installed at the base of shafts enclosing the supply and overflow piping. The pipe shall lead to an open sight drain or to an open sump.
(4) Oil lines for equipment or tanks shall be steel pipe ASTM A 53 or A 106, grade B seamless, schedule 40 with welded connections up to the oil tank or equipment, except that fittings at the tank or equipment, shut off valves and other fuel oil flow and control devices may be screwed or flanged.
(5) Pipe shafts shall not be penetrated by or contain other piping or ducts.
(6) The piping shall be located and secured from movement so as to prevent undue stress on the piping and to isolate the piping from vibrations from any equipment.
(7) Pipe connections to the main header (supply or return) shall be made from the top of the header, except for systems described in paragraph (11) of this subdivision.
(8) Required air vents and vacuum breakers shall be designed for their required use.
(9) All air vents and vacuum breakers shall be hard piped to a curb or pan as provided for in subdivision (b) of section 27-829.
(10) 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 four inches. However, where an applicant demonstrates by the inclusion of calculations on the plans that a greater diameter is necessary to ensure the proper flow for the functioning of the system, such greater diameter may be permitted. All oil stored above the lowest floor shall be in tanks complying with subdivision (b) of section 27-829 of this code; piping shall not be used for fuel storage purposes.
(11) 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 two hundred seventy-five gallons of oil storage per story as provided for in subdivision b of section 27-829 of this code.
(g) Heating coils in storage tanks. The heating of oil in storage tanks shall be by means of coils using low pressure hot water or steam, or by means of electric heaters approved for use in oil storage tanks.
(h) Valves and devices to control the flow of oil.
(1) Where more than one storage tank is connected to a common supply line, a shut-off valve shall be provided in the supply line at each tank. Where more than one burner is connected to a supply line a shut-off valve shall be provided at each burner. Where a single tank and a single burner are installed, a shut-off valve shall be required in the supply line at the tank and another at the burner. Valves shall be brass or equivalent in corrosion and fire resistance, shall provide tight shut-off, and shall be rated at one hundred twenty-five psi or greater as required by the pressure in the system.
(2) Where a storage tank is located so that the top of the tank is above the oil inlet to the burner or to the fuel pump, and the storage tank capacity is greater than two hundred seventy-five gallons, the supply line to the burner shall be provided with an approved anti-syphon device. The device shall be located at the highest point in the supply line. Where an approved foot valve is used in the tank and the tank is constructed with a manhole, an anti-syphon device shall not be required. No anti-syphon device shall be required where no. 6 fuel oil is used.
(3) The pressure in oil lines to burners located above the lowest floor of a building shall not be more than is required to circulate oil to and from the burners, and all parts of the oil system shall be capable of withstanding the maximum working pressure in that part of the system.
(4) A remote control shall be provided to stop the flow of oil to any burner. Such control shall be located outside the entrance to the room in which the burner is located and as close to such entrance as practicable, except that when an outside location is impracticable, such control may be located immediately inside the room in which the burner is located, provided such location is accessible at all times. All such controls shall be permanently labeled "remote control for oil burner." On storage tanks of sixty gallon or less capacity used with manually operated burners, such remote control may be installed in the supply lines between tank and burner.
(5) Pressure in a storage tank for the purpose of discharging oil shall be prohibited.
(6) In systems where either steam or air is used for atomizing the oil, the oil and the atomizing supply shall be interlocked so that where the supply of either is interrupted, the supply of the other will be immediately cut off.
(i) Oil level indicating devices and test wells.
(1) All tanks located inside buildings shall be provided with an oil level indicating device. Test wells shall be prohibited in tanks located inside of buildings. Unused tank openings shall be permanently sealed to prevent the removal of plugs or cover.
(2) Oil level indicating devices shall be designed and constructed of substantial materials so that there can be no leakage of oil or oil vapor.
(3) Test wells in storage tanks located outside of buildings shall be capped oil tight and kept closed when not in use.
