New Cares Brought On by Oil Burners
Necessary to Have Special Safeguards to Business District Because of the Oil Heating Systems—Some of the Regulations
OIL, as a fuel, is not exactly a new discovery. It has been used for years to furnish heat for industrial furnaces. It is only in the last ten years or even less that it has come into the field as a fuel for heating houses.
Two things may be mentioned as helping to bring this about. One is the large production of oil of a suitable quality at a price to compete with anthracite; the other is the development of burners to use the available grades of oil. Like many other new things coming into sudden popularity, the oil burner idea stimulated into activity a number of inventors and would be inventors and promoters. It seemed, as remarked by one oil burner man, that “every man who had a screw-driver and a wrench thought he could build a successful oil burner.”
Another hazard arose from the appearance on the market of numerous oil burners mostly of the natural draft variety, some widely advertised and sold to dealers or users regardless of the qualifications of the buyer to install and adjust such a device. Many honest men squandered the savings of years in the hope of getting rich in the oil burner business, only to find that it cost more than the original profit to keep some of these early burners sold.
List Made of Satisfactory Burners
Fortunately this condition of affairs is beginning to correct itself but in the smaller towns it is likely to be a slow process as the opportunity to observe the fate of certain burners is limited. There is, however, a means by which the public can avoid the danger of unsafe devices. Underwriters’ laboratories have for several years been investigating the hazards of oil burners and at times have had 11 furnaces running 16 hours a day. testing oil burners under various conditions. We have a list of burners that have satisfactorily passed these tests and other necessarv requirements so as to bear the underwriters’ label.
Type of Town Influences Kind cf Burner
The size of the town and the size and character of the buildings has much to do with the kind of oil burners used. In large city buildings where a regular engineer or fireman is employed, large boilers or furnaces are used and the engineer is responsible for its safe operation. Here we find usually a burner of the industrial type, while in the smaller buildings with heating plants of the domestic type automatic safety devices are needed and usually the entire operation is automatic.
The safety of the industrial type depending mainly on proper knowledge and care on the part of the attendant, it will be necessary to mention only one or two features at this time. Such burners are usually supplied with oil under more or less pressure by means of a pump, the air supply being regulated by the attendant. Improper adjustment of air supply sometimes results in high stack temperatures so that if a metal breaching or smoke pipe exposes combustible material, a fire may be started. Unless the pipe is insulated a shield of fireproof material should be interposed to protect the wood. Such a heating plant should he installed in a fireproof boiler room. We sometimes find a damper in the stack to control the draft. Such a damper should be so made that when closed it will not cut off more than 80% of the stack area. When a weight is used to assist in controlling the stack damper, it should be so attached that if the controls are released the weight will tend to open rather than close it.
Problem of Oil Storage is Serious
A serious problem with oil burner installation is oil storage, particularly with industrial burners and others capable of handling large furnaces and using the heavier and cheaper oils. It is often desired to install tanks with a capacity of 10,000 to 15,000 gallons. The best place for such a tank is underground below the level of the pump supplying the burner. If it can not be below the pump level it should at least be under ground if possible. In city property it is sometimes impossible to provide a place outside the walls of the building and the tank is either buried under the basement floor or enclosed in a space walled off from the basement. In the latter case the tank should be cut off from the rest of the building by walls of 12-inch concrete or the equivalent and the space covered by a slab of reinforced concrete. The space around the tank must be filled with sand or well packed earth to prevent the accumulation of combustible vapor. Whenever it is necessary to locate the tank so that the oil level is higher than the burner or pump, some arrangement is necessary to prevent siphoning in case of accident to the piping.
There are several devices or schemes recognized by the underwriters for this purpose. A number of manufacturers can provide tanks listed and labelled by underwriters’ laboratories.
I would like to call your attention to the fact that an underwriter’s tank for such use has no bottom connections.
Inside Tank Sometimes Used
The automatic oil burner is usually limited to furnaces such as are used for heating houses and smaller mercantile buildings where it is not practical to have a regular attendant. In connection with these an inside tank is sometimes used with a limit of 275 gallons stored inside the building. The underwriters’ rules permit such a tank to be connected so as to feed by gravity to a properly safeguarded oil burner, but this is recognized as more of a hazard than the arrangement requiring a pump to lift the oil to the burner.
The list of domestic burners includes both those with complete automatic control and those with manual regulation but with automatic devices for stopping the flow of oil if the fire goes out or if oil is fed to the burner faster than it can be burned. Most automatic burners have pump feed and mechanical draft although there are automatic burners with natural draft or gravity feed or with both.
There are 60 oil burners of the domestic type which have successfully passed the examination and tests of Underwriters’ laboratories. The list includes those with manual control as well as those which are completely automatic; some pump feed and some gravity feed ; some depending on natural draft and some with blowers or mechanical draft. The label is evidence of proper construction at the factory.
Usually the manufacturer of a labelled burner will see to it that installations are properly made, but this is sometimes not easy where shipments are made to distant points. Even when this is done the owner or some local service man may disturb the arrangement.
Points for the Inspector
The following points should be noted in inspecting the plant in operation.
If the tank is outside under-ground, it should be below the level of the pump which supplies the burner or if this is im practical, means must be provided to prevent siphoning or gravityflow in case of damage to the piping. If a 275-gallon inside tank is installed, it must be on substantial incombustible supports, and the fill pipe and also the vent pipe must open outside the building and be so located as to avoid the likelihood of oil or vapor entering the building through a door or window. The till pipe must have a cap which may be locked and the vent pipe which should be not smaller than 1inch pipe size, must have a weather proof hood, screened to keep out insects.
“It is a wise thing to have a good fire extinguisher in the furnace room regardless of the kind of fuel, and with fuel oil, an extinguisher approved for oil fires should be used. Near every oil burning furnace there should be a card giving complete instructions for the care and operation of the system, and this should be placed under a glass and framed.”
There should be a test well or gauge so designed as to prevent escape of oil or gas in the building, gage glasses which would if broken allow the escape of oil or vapor must not be used.
Rules for Piping
The piping must be standard full weight iron steel or brass with substantial fittings. Care must be taken to run the pipe where it will not be exposed to damage. When it is necessary to cross the floor a groove or trench should be made for the pipe and afterward refilled with cement or provided with a steel or iron cover. Supply pipe must be not less than 1/4-inch iron pipe size. Return pipe from pump must be at least as large as supply pipe and overflow from auxiliary tank to storage tankshould be larger than supply pipe. A pipe fitter on his first job of oil piping is likely to find that he has something to learn. Considerable care even by experienced fitters is needed to be sure of a perfectly oil-tight job. My personal opinion is that nothing smaller than 3/8-inch pipe should be used except for short connections which might be considered part of the burner. Unions are necessary at or near the burner to provide for disconnecting the burner and these must be approved unions of a type which does not require packing or gaskets. Approved valves must be provided near the burner and also at the tank. Valves should be installed so as to close against the pressure. In connection with pipe sizes, I would call attention to the overflow provided on all burners in which the oil is vaporized rather than atomized. This is a safeguard against the overflow of oil onto the floor or into the ash pit when for any reason the fire is accidentally extinguished or receives more oil than can be burned. It provides for the overflow of the unburned oil into a small bucket or into a chamber containing a float so that a small amount of oil overflowing will cause the closing of a valve to stop the flow of oil.
The overflow pipe must Ire not smaller than 1/2-inch iron pipe size and the opening from the burner into this pipe must be protected or so located that it can not be obstructed by carbon or other matter that may accumulate. In reviewing a list of 100 fire department calls due to oil burners, over one-third were caused by overflow of oil, where the overflow shut off failed to operate because of a small pipe or overflow opening becoming clogged.
Chimney Should Not be Obstructed
It is important that the smoke pipe and chimney be not obstructed and that no damper be used which will cut oft over 80 per cent of the opening. Instances have occurred with a smoky burner, which usually means insufficient air for the amount of oil, or perhaps a poorly designed burner, that accumulations of soot have so reduced the smoke passages that a mixture of oil vapor and air in the furnace would be ignited and cause an explosion sufficient to blow open the furnace door and the house would be filled with sooty smoke even though the fire remained in the furnace.
Conditions Around Furnace
I would cal! attention to the recommendations of the National Hoard of Underwriters regarding the general arrangements around the furnace. No combustible material should be stored within ten feet of the furnace. Any woodwork, wooden lath and plaster partitions or other combustible material within four feet of the sides or back or eight feet of the front of the furnace shall be covered with approved plaster hoard or other approved incombustible material. Above the furnace there shall be constructed a ceiling consisting of plaster board covered with sheet metal, or cement plaster on metal lath, to extend four feet beyond the sides and back and eight feet in front.
At least a 36-inch clearance is necessary between breeching or smoke pipe and combustible material unless breeching and flues arc insulated with 2 to 4-inch asbestos magnesia lagging or equivalent, in which case the distance may be reduced to eighteen inches. The ordinary coal burning furnace is not always designated to take up the heat from oil burning with high efficiency and the gases going out the stack are apt to have a high temperature which, of course, increases the fire hazard from hot smoke pipes. Several fires have been caused in this way.
It is a wise thing to have a good fire extinguisher in the furnace room regardless of the kind of fuel and with oil fuel one approved for oil fires should be used.
Last but not least—near every oil burning furnace there should IKa card giving complete instructions for care and operation of the system. This should be placed under glass and framed.
Prospect. N. Y., Receives Apparatus—”Deluge” fire apparatus has been delivered to Prospect, N. Y.