Cutting the Fire Danger of Oil Burner Installations
Device Must Be Correct in Principle and Well Constructed—Proper installation and Maintenance Essential—Important Points Explained
THE use of oil as a domestic fuel is so new a field that any information on the subject of its fire hazards and the proper maintenance of oil burners is welcomed by fire chiefs and others interested in the subject. The following article is replete with facts along this line:
Oil has played, and will play for a considerable period of time, in all probability, a prom_____nent part in our national and international relations: but not until recently, have we given much concern regarding the part it is beginning to play in our domestic affairs. The prevailing coal shortages and accompanying high prices have forced the great buying American public to seek available and cheaper fuel. As a result of the demand put forth on the part of the public, the combustion, the mechanical and the electrical engineers, as well as the “jack-of-all-trades” of the country have made and attempted to make oil burning devices for domestic use. Some of these devices are well manufactured, of suitable material, and safeguarded as far as the advancement of the art dictates, while a number are nothing more or less than piles of hardware, introducing a real menace to life and are an ever present agent to increase our National Ash Heap. Those devices that in principle possess real merit and are equipped with up-to-date safeguards may still be hazardous. Unless an oil burner is properly constructed, installed, and maintained, it may not be considered as having been safeguarded so far as practicable. This article from a fire prevention viewpoint may be termed a brief survey on “How To Do It and How Not To Do It” with respect to the construction, installation and maintenance of domestic oil burning equipments. Briefly, it is thought that the factors that will enhance the success of any domestic oil burner are:
Factors Entering Into Success of Oil Burners
First: That the device be correct in principle and properly constructed.
Second: That the device be sold correctly.
Third: That the device be installed and maintained correctly.
Experience over an extended period of time involving research and the testing of domestic oil burners leads to the grouping of such burners into two distinct classes. In the first class are those constructed by the cut and dry method, in which little or no consideration has been given to varying conditions under which the device will be called upon to perform in actual service, to the character and combustion of the fuel utilized in the device, to the known physical properties of the metals employed in the assembly, to the safeguarding of the equipment against the tampering of the laymen. or to internal phenomena that lead to or introduce additional hazards. In the second class are those designed prior to their construction through a test sample, in which careful attention has been paid to all features previously mentioned.
Actual Service Test of Efficiency
When subjected to actual service conditions, covering an extended period of time, the burner of the first type has been observed, in most cases, to fail in operation, and in the failure the construction, in some cases, introduced hazards jeopardizing property to a great extent. It is deemed advisable. from a fire protection viewpo nt, that domestic oil burners be designed in proper sizes or with some form of adjustment to meet the varying field conditions with respect to the many different types of the existing heating units and their inherent characteristics, and that combustion of the fuel specified by the manufacturer of the device be proven suitable using oils of both the asphaltum and paraffin bases. It is also necessary to determine whether the materials eraployed in the assembly, with particular reference to those exposed to high temperatures, possess properties that will insure durability and reliability of operation for an extended period of time, and ascertain, also, whether the device is safeguarded with apparatus that will render the equipment inoperative in event of flooding or other internal phenomena in the heating equipment that may introduce fire and casualty hazards.
(Continued on page 659)
(Continued from page 637)
Method of Sale Factor in Fire Hazard
While the method of sale of oil burning equipments is largely a question of house policy of the manufacturer, it may appear to be far-fetched to the average individual for those interested in the reduction of fire hazards to state, that this is a factor also concerning them; nevertheless, this is a fact. As an illustration, over-zealous salesmen often, through a firm belief in their product and the lact of technical enlightenment, misrepresent to the innocent American buying public, the character of the fuel that their equipment will consume, its economy as compared to coal and low operating costs; and fail, in many cases, to make a careful survey of the installation in which the burner is to be installed. The purchaser finds that he can buy the fuel of the specific gravity recommended by the salesman, but when placed in service, the device is soon inoperative or tails to function. Varying conditions imposed on the equipment fail to substantiate the low cost of operation and economy of fuel as compared to coal and that the burner capacity is adequate for the heating plant. The purchaser then assumes that the equipment is out of order, as the sales talk assured proper performance on all of these points, and he proceeds to make adjustments to accomplish these ends. As a result of tampering on part of the average layman, fire and casualty hazards often follow. It is thought and here suggested that the house policy with regard to sales propaganda and talk should be confined strictly to facts, particularly those of a technical nature, and that all salesmen should be carefully and thoroughly schooled before attempting to secure contracts.
Installation Divided Into Three Phases
The installation of an oil burning system may be divided into three distinct phases; namely, the tanks, the pipe lines, and the burner proper, and. in many instances, the electrical phase. Each phase offers certain outstanding problems, which, if neglected, are liable to introduce hazardous conditions.
In the matter of tanks, three types of installations are commonly employed. In the first and most common type of installation the auxiliary supply tank is used for main storage. In the second type an auxiliary supply tank filled from an underground storage tank is employed; and in the third type, a force pump, drawing fuel oil from a storage tank located below or above the point of consumption is used.
How Not to Install Oil Burner
Before discussing in detail the more desirable methods of installation, it is thought advisable to present here a compilation of misinformation that has been doled out to the public by individuals who apparently have given the question of safety a very minor position in presenting their article to the ultimate consumer. To bring out clearly this compilation. the reader’s attention is invited to Fig. 1 which might be titled. “How Not to Install an Oil Burner.” In the illustration the letters refer to the following:
- Storage tank above ground.
- Ripe line between the storage and auxiliary tanks and leading from the bottom of the large container.
- Use of flanged unions with rubber gaskets.
- Glass gauge located in basement, and employed in the line to indicate the oil level of the storage tank.
- Shut-off valve without standard packing box.
- Impossibility of having an overflow pipe from the auxiliary tank to the storage tank.
- Ordinary cork float gauge, with stem projecting through top of tank.
- Auxiliary tank vented inside of basement.
- Tank constructed of very thin material and unprotected from corrosion.
- Tank resting on combustible support.
- Support not fixed to floor.
- No means for cleaning auxiliary tank.
- Ripe line to burner exposed.
- Ripe connections to tank secured by soldered flanges.
NOTE: All of the preceding items are not shown in detail by Fig. 1, but the list may be considered as an example of what actually has been found in service.
Outstanding Hazard of Each Feature
The outstanding hazards connected with each of the features as lettered in the foregoing paragraph are as follows:
- Should a pipe line rupture or leak, the contents of the storage tank will be discharged into basement.
- Rubber will in time become useless as a gasket when in contact with the liquid fuel.
- Breakage of glass gauge w ill discharge the contents of the storage tank into the furnace room.
- Valve subject to leaks due to leaking stuffing box and if left open even slightly will discharge oil into the basement.
- No means provided for discharging excess oil to main storage.
- Should tank be filled to capacity, liquid fuel will be discharged into the room.
- In event of a basement fire oil vapors will increase the hazard.
- Thin material subject to leakage.
- In event of fire, supports will be consumed and fuel added to the flames.
- External shocks applied to the tank will strain connections and cause leakage of liquid fuel.
- Necessitates dismantling lines, and in all probability re assembly will not be accomplished in a manner that will insure tightness of joints.
- Application of external shocks to small pipe line will likely result in leakage or severe strains on connections, causing leakage.
- Flanges which are not riveted as well as soldered are almost certain to fail and permit discharge of oil through the fuel opening into the tank.
Installation of Tanks
In studying the existing requirements covering the installation of tanks for domestic oil burning equipments, there are two installation forms that may be followed and which assure a reasonable degree of safety. These are shown by Fig. 2 and 3. In Fig. 2. the labeled storage tank (O) is buried beneath the lowest level of the basement floor line and filled and vented by means of a standard fill and vent fitting (P). The oil is drawn from the underground storage tank by means of a standard hand pump (M), through a standard strainer (N). and discharged into an auxiliary tank (E), constructed of a metal not less than No. 18 U. S. gauge and whose capacity does not exceed 60 gal. The unions (K) used in this assembly are of the brass to iron conically seated type. The tank is equipped with an overflow line (L) at least one pipe size larger than the discharge line leading from the pump, and also with a weather-proof, hooded vent (B) terminating outside of the building.
The auxiliary tank Fig. 2. is also provided with an indicating guage (D) of a type in which the breakage of the glass will not discharge oil into the building. The tank is mounted on a support (G) and (J), of a non-combustible material that is rigidly fixed to the floor (P). All connections to the tank are assembled by rivets and solder or by the welding process. The piping between the auxiliary tank and the burner (I) is cither buried in a concrete trench or snugly run in corners of the basement to afford the maximum protection. The tank is provided with a means (F) for cleaning out the usual foreign matter held in suspension in liquid fuel with may pass the strainer (N).
In Fig. 3, the inside tank contains the entire storage. The same practice with respect to the tank is followed as shown for the auxiliary tank in Fig. 2, with the exception that the tank is filled from the outside of the building.
The roofs of subways, the presence of tide waters and other of nature’s natural obstructions have forced the users of oil burning devices to store liquid fuel above the point of consumption, and should a pipe line rupture occur in installations where pumps are employed to draw the fuel from the tank, a syphon may be created and discharge the contents of the storage tank into the furnace room. In Fig. 4, a diagrammatic sketch is given showing a pump at (A) drawing the liquid fuel from storage tank (B) through an antisyphoning device at (C). This anti-syphoning arrangement may be secured by different methods, but the end to be secured is to have all pipe connections into the tank located above the liquid level and the discharge of oil in case of pipe breakage effectually prevented.
Equipment Should Be Examined Every Day
It has been observed in some instances where devices that are safeguarded as far as the state of the art dictates, and installed in accordance with the regulations covering the class, that operating troubles are often experienced by the purchaser. Upon investigation of the causes leading to this trouble, the service man finds that little or no attention has been given the device. Mechanical appliances must be examined frequently to insure proper performance. Manufacturers are furnishing maintenance instructions, and if proper functioning of the device is to be reasonably expected, these must be followed. It is considered good practice by those actively engaged in this work to thoroughly examine these equipments once each day.
In conclusion it has been noted that many localities have not made use of the available information on this subject that is published by the National Board of Fire Underwriters. 76 William Street, New York City, which will, upon request, be supplied free of charge. As a result, a very wide difference of practice is manifested in the types of burners and installations permitted. Only those types of equipments the merits of which have been tested and proven and which are installed in accordance with practices accepted by the authorities, should, on the part of the departments having jurisdiction, be allowed, if we who are attempting to safeguard America give the public what it is asking of us. — From Laboratories Data—Organ of Underwriters’ Laboratories.