RULES AND REGULATIONS RELATING TO CONSTRUCTION, INSTALLATION, INSPECTION, MAINTENANCE AND USE

Memphis Code of Ordinances tit. 14, ch. 14-12, art. 4

in effect

Memphis Code of Ordinances § 14-12-51 Power boilers—New installations.

Sec. 14-12-51. - Power boilers—New installations. A. No power boiler, except reinstalled boilers and those exempted by these rules and regulations, shall hereafter be installed in this city unless it has been constructed, inspected and stamped in conformity with the city boiler construction code and is approved, registered and inspected in accordance with the requirements of these rules and regulations. B. A boiler having the standard stamping of any state that has adopted a standard of construction equivalent to the standard of the city may be accepted by the chief inspector; provided however, that, the person desiring to install the boiler shall make application for the installation and shall file with this application the manufacturer's data covering the construction of the boiler in question. C. All new boiler installations, including reinstalled boilers, shall be installed in accordance with the requirements of the latest revision of the A.S.M.E. Boiler Construction Code and these rules and regulations. D. Upon the completion of installation and proper permits acquired, all boilers shall be inspected by the chief inspector, a deputy inspector or a special inspector. At the time of this inspection, the boilers shall be stamped with a serial number of the city followed by letters "MFS," such letters and figures to be not less than 5/16 of an inch in height. Stamping shall not be concealed by lagging or paint and shall be exposed at all times. (Code 1967, § 45-81; Code 1985, § 42-86)

Memphis Code of Ordinances § 14-12-52 Power boilers—Existing installations.

Sec. 14-12-52. - Power boilers—Existing installations. A. Application of section. This section shall apply to existing power boiler installations. B. Maximum allowable working pressure for standard boilers. The maximum allowable working pressure for standard boilers shall be determined in accordance with the applicable provision of the edition of the A.S.M.E. Code under which they were constructed and stamped. C. Maximum allowable working pressure for nonstandard boilers. The maximum allowable working pressure on the shell of a nonstandard boiler or drum shall be determined by the strength of the weakest section of the structure computed from the thickness of the plate, the tensile strength of the plate, the efficiency of the longitudinal joint or tube ligaments, the inside diameter of the outside course and the factor of safety allowable by these rules. TS × t × E | = | Maximum allowable working pressure in lb. per sq. in. gauge R × FS R × FS Where TS = Ultimate tensile strength of shell plates, lb. per sq. in. t = Minimum thickness of shell plate, in weakest course, in inch. E = Efficiency of longitudinal joint. For riveted construction, E shall be determined by rules given in paragraph P-181 of A.S.M.E. Boiler Construction Code for Power Boilers. For fusion welded construction, E shall be determined by rules in paragraph P-102 of A.S.M.E. Boiler Construction Code for Power Boilers. For tube ligaments, E shall be determined by rules in paragraphs P 192 and P 193 of A.S.M.E. Boiler Construction Code for Power Boilers. For seamless construction, E shall be considered 100 percent. R = One-half the inside diameter of the weakest course of shell or drum in inches. FS = Factor of safety permitted. 1. Tensile strength. When the tensile strength of steel or wrought iron shell plates is not known, it shall be taken as 55,000 pounds per square inch for steel and 45,000 pounds per square inch for wrought iron. 2. Crushing strength of mild steel. The resistance to crushing of mild steel shall be taken at 95,000 pounds per square inch of cross sectional area. 3. Strength of rivets in shear. When computing the ultimate strength of rivets in shear, the following values in pounds per square inch of the cross sectional area of the rivet shank shall be used: Iron rivets in single shear | 38,000 Iron rivets in double shear | 76,000 Steel rivets in single shear | 44,000 Steel rivets in double shear | 88,000 When the diameter of the rivet holes in the longitudinal joints of a boiler is not known, the diameter and cross sectional area of rivets, after driving may be selected from the following table or ascertained by cutting out one rivet in the body of the joint: _____ Sizes of Rivets Based on Plate Thickness Thickness of plate | ¼″ | 9/32 ″ | 5/16 ″ | 11/32 ″ | ⅜″ | 13/32 ″ Diameter of rivet after driving | 11/16 ″ | 11/16 ″ | ¾″ | ¾″ | 13/16 ″ | 13/16 ″ Thickness of plate | 7/16 ″ | 15/32 ″ | ½″ | 9/16 ″ | ⅝″ Diameter of rivet after driving | 15/16 ″ | 15/16 ″ | 15/16 ″ | 1 1/16 ″ | 1 1/16 ″ 4. Factors of safety. The following factors of safety shall be increased by the inspector if the condition and safety of the boilers demand it. a. The lowest factor of safety permissible on existing installations shall be 4.5 excepting for horizontal return tubular boilers having continuous lap seams more than 12 feet in length where the factor of safety shall be eight, and when this latter type of boiler is removed from its existing setting, it shall not be reinstalled for pressures in excess of 15 pounds per square inch gauge. b. Reinstated or secondhand boilers shall have a minimum factor of safety of six when the longitudinal seams are of lap riveted construction and a minimum factor of safety of five when the longitudinal seams are of butt and double strap construction. 5. Age limit of fire tube boilers. The age limit of a horizontal return tubular, flue or cylindrical boiler having a longitudinal lap joint and operating at a pressure in excess of 50 pounds per square inch gauge shall be 30 years. A reasonable time for replacement shall be given at the discretion of the director not to exceed one year. 6. Welded boilers. Boilers having either longitudinal or circumferential seams of fusion welded construction shall have been constructed and stamped in accordance with the rules and regulations of the A.S.M.E. Boiler Construction Code or shall have the standard stamping of another state that has adopted a standard of construction equivalent to the standards of the A.S.M.E. Boiler Construction Code. 7. Pressure on old boilers. In no case shall maximum working pressure of an old boiler be increased to a greater pressure than would be allowed for a new boiler of same construction. 8. Cast iron headers and mud drums. The maximum allowable working pressure on a water tube boiler, the tubes of which are secured to cast iron or malleable iron headers or which have cast iron mud drums, shall not exceed 160 pounds per square inch gauge. 9. Pressure on cast iron boilers. The maximum allowable working pressure for any cast iron boiler, except hot water boilers, shall be 15 pounds per square inch gauge. D. Safety valves. The use of weighted-lever safety valves shall be prohibited and these valves shall be replaced by direct spring-loaded pop type valves that conform to the requirements of the A.S.M.E. Boiler Construction Code for Power Boilers. Safety valves having either the seat or disc of cast iron shall not be used. Each boiler shall have at least one safety valve and if it has more than 500 square feet of water heating surface, it shall have two or more safety valves. The valve or valves shall be connected to the boiler, independent of any other steam connection and attached as close as possible to the boiler without unnecessary intervening pipe or fittings. Where alteration is required to conform to this requirement, owners or users shall be allowed one year in which to complete the work. No valve of any description shall be placed between the safety valve and the boiler nor on the escape pipe (if used) between the safety valve and the atmosphere. When an escape pipe is used, it shall be full size and fitted with an open drain to prevent water lodging in the upper part of the safety valve or escape pipe. When an elbow is placed on a safety valve escape pipe, it shall be located close to the safety valve outlet of the escape pipe, shall be securely anchored and supported. All safety valve discharges shall be so located or piped as to be carried clear from walkways or platforms used to control the main stop valves or boilers or steam headers. The safety valve capacity of each boiler shall be such that the safety valve or valves will discharge all the steam that can be generated in the boiler without allowing the pressure to rise more than six percent above the highest pressure to which any valve is set and in no case to more than six percent above the maximum allowable working pressure. One or more safety valves on every boiler shall be set at or below the maximum allowable working pressure. The remaining valves may be set within a range of three percent above the maximum allowable working pressure, but the range of setting of all of the safety valves on a boiler shall not exceed ten percent of the highest pressure to which any valve is set. When two or more boilers operating at different pressures and safety valve settings are interconnected, the lower pressure boilers or interconnected piping shall be equipped with safety valves of sufficient capacity to prevent over pressure considering the generating capacity of all boilers. In those cases where the boiler is supplied with feed water directly from pressure mains without the use of feeding apparatus (not to include return traps), no safety valve shall be set at a pressure greater than 94 percent of the lowest pressure obtained in the supply main feeding the boiler. The relieving capacity of the safety valves on any boiler may be checked by one of the three following methods and, if found to be insufficient, additional valves shall be provided: 1. By making the accumulation test, which consist of shutting off all other steam-discharge outlets from the boiler and forcing the fires to the maximum. The safety valve capacity shall be sufficient to prevent a pressure in excess of six percent above the maximum allowable working pressure; 2. By measuring the maximum amount of fuel that can be burned and computing the corresponding evaporative capacity (steam generating capacity) upon the basis of the heating valve of this fuel. These computations shall be made as outlined in the appendix of the A.S.M.E. Boiler Construction Code for Power Boilers; 3. By determining the maximum evaporative capacity by measuring the feed water. When either of the methods outlined in subsection (D)(2) or (3) of this section is employed, the sum of the safety valve capacities shall be equal to or greater than the maximum evaporative capacity (maximum steam generating capacity) of the boiler. E. Boiler feeding and feed piping. All boilers shall have a feed supply which will permit the boilers being fed at any time while under pressure. A boiler having more than 500 square feet of water heating surface shall have at least two means of feeding, one of which shall be an approved feed pump, injector or inspirator. Where a source of feed directly from pressure mains is available at sufficient pressure to feed the boiler against a pressure six percent greater than the release pressure of the safety valve with the highest release setting, this may be considered one of the means. The feed water shall be introduced into the boiler in such manner that it will not be discharged close to riveted joints of shell or furnace sheets or directly against surfaces exposed to gases at high temperature or direct radiation from the fire. The feed piping to the boiler shall be provided with a check valve near the boiler and a valve or cock between the check valve and the boiler. When two or more boilers are fed from a common source, there shall also be a valve on the branch to each boiler between the check valve and source of supply. Whenever a globe valve is used on feed piping, the inlet shall be under the disc of the valve. In all cases where returns are fed back to the boiler by gravity, there shall be a check valve and stop valve on each return line, the stop valve to be placed between the boiler and the check valve and both shall be located as close to the boiler as is practicable. Where deaerating heaters are not employed, it is recommended that the temperature of the feed water be not less than 120 degrees Fahrenheit to avoid the possibility of setting up localized stress. Where deaerating heaters are employed, it is recommended that the minimum feed water temperature be not less than 215 degrees Fahrenheit so that dissolved gases may be thoroughly released. F. Fusible plugs. Fire-actuated fusible plugs if used shall con form to the requirements of the A.S.M.E. Boiler Construction Code for Power Boilers. G. Water columns, gauge glasses and gauge cocks. No outlet connections (except for damper regulator, low water fuel cutout, drains, steam gauges or such apparatus that does not permit the escape of an appreciable amount of steam or water therefrom) shall be placed on the piping that connects the water column to the boiler. The water column shall be provided with a valved drain of at least three-fourths-inch pipe size, the drain to be piped to a safe location. Each boiler shall have three or more gauge cocks, located within the range of the visible length of the water glass, except when such boiler has two water glasses with independent connections to the boiler, located on the same horizontal line and not less than two feet apart. For all installations where the water gauge glass or glasses are more than 30 feet from the boiler operating floor, it is recommended that water level indicating or recording gauges be installed at eye height from the operating floor. H. Steam gauges. Each steam boiler shall have a steam gauge, with dial range not less than 1½ times the maximum allowable working pressure, connected to the steam space or to the steam connection to the water column. The steam gauge shall be connected to a siphon or equivalent device of sufficient capacity to keep the gauge tube filled with water and so arranged that the gauge cannot be shut off from the boiler except by a cock placed near the gauge and provided with a tee or lever handle arranged to be parallel to the pipe in which it is located when the cock is open. When a steam gauge connection longer than eight feet becomes necessary, a shut-off valve may be used near the boiler provided the valve is of the outside screw and yoke type and is locked open. The line shall be ample size, with provision for free blowing. Each boiler shall be provided with a one-quarter-inch nipple and globe valve connected to the steam space for the exclusive purpose of attaching a test gauge when the boiler is in service so that the accuracy of the boiler steam gauge may be ascertained. I. Stop valves. Each steam outlet from a boiler (except safety valve connections) shall be fitted with a stop valve located as close as practicable to the boiler. When a stop valve is so located that water can accumulate, ample drains shall be provided. The drainage shall be piped to a safe location and shall not be discharged on the top of the boiler or its setting. When boilers provided with manholes are connected to a common steam main, the steam connection from each boiler shall be fitted with two stop valves having an ample free flow drain between them. The discharge of this drain shall be visible to the operator while manipulating the valves and shall be piped clear of the boiler setting. The stop valves shall consist preferably of one automatic nonreturn valve (set next to the boiler) and a second valve to the outside-screw and yoke type. J. Blow-off piping. The construction of the setting around each blow-off pipe shall permit free expansion and contraction. Careful attention shall be given to the problem of sealing these setting openings without restricting the movement of the blow-off piping. All blow-off piping, when exposed to furnace heat, shall be protected by fire brick or other heat resisting material so constructed that the piping may be readily inspected. Each boiler shall have a blow-off pipe fitted with a valve or cock, in direct conflection with the lowest water space. Cocks shall be of the gland or guard type and suitable for the pressure allowed. The use of lobe valves shall not be permitted. When the maximum allowable working pressure exceeds 100 pounds per square inch gauge, each blow-off pipe shall be provided with two valves or a valve and cock, such valves and cocks to be not less than extra heavy type. When the maximum allowable working pressure exceeds 100 pounds per square inch gauge, blow-off piping shall be not less than extra heavy from the boiler to the valve or valves and shall be run full size without use of reducers or bushings. The piping shall be wrought iron or steel and shall not be galvanized. All fittings between the boiler and blow-off valve shall be steel. In case of renewal of blow-off pipe or fittings, they shall be installed in accordance with the rules and regulations for new installations. K. Repairs and renewals of boiler fittings and appliances. Whenever repairs are made to fittings or appliances or it becomes necessary to replace them, the work shall comply with the provisions of this chapter for new installations. L. Stamping of existing boilers. Each boiler shall be stamped with a serial number of the city followed by the letters "MFS," such letters and figures to be not less than 5/16 inch in height. The stamping shall not be concealed by lagging or paint and shall be exposed at all times. M. Suggested operating practices. It is recommended that the suggested rules of the A.S.M.E. Boiler Construction Code covering the care of power boilers and pressure vessels be used as a guide for proper and safe operating practices. (Code 1967, § 45-82; Code 1985, § 42-87; Ord. No. 1427, § 1, 8-29-1972)

Memphis Code of Ordinances § 14-12-53 Boiler runway or platform.

Sec. 14-12-53. - Boiler runway or platform. A. Runway or platform. Where necessary for safety, there shall be a steel runway or platform of standard construction installed across the tops of adjacent boilers or at some other convenient level for the purpose of affording safe access. The inspector shall notify the chief inspector of owners or users who must provide for these requirements and the chief inspector shall give written notice to the owner or user that the installation be made. The owner or user shall be allowed one year from the date of the chief inspector's notification in which to complete the work. All runways shall have at least two means of exit, each to be remotely located from the other. B. Exits from boiler rooms. To lessen the hazard of being trapped within the boiler room, ash pit aisles or other locations, there shall be at least two means of exit as may be considered necessary by the chief inspector or the board of boiler rules. Each elevation shall be provided with at least two means of egress, each to be remotely located from the other. All authorized inspectors shall notify the chief inspector of owners or users who must provide for these requirements. The chief inspector then shall give written notice to the owner or user that the necessary work must be completed within six months from the date of notification. C. Conditions not covered by section. All cases not specifically covered by this section shall be treated as new installations, or may be referred to the chief inspector for instructions concerning the requirements. (Code 1967, § 45-83; Code 1985, § 42-88)

Memphis Code of Ordinances § 14-12-54 Miniature boilers—New installations.

Sec. 14-12-54. - Miniature boilers—New installations. A. No miniature boiler, except reinstalled boilers and those exempted by these rules and regulations, shall hereafter be installed in this city unless it has been constructed, inspected and stamped in conformity with section 5 of the A.S.M.E. Boiler Construction Code and is approved, registered and inspected in accordance with these rules and regulations. B. A miniature boiler having the standard stamping of a state that has adopted a standard of construction equivalent to the standard of construction of this state may be accepted by the chief inspector; provided however, that the person desiring to install the same shall make application for the manufacturer's data report covering the construction of the boiler in question. C. All new installations of miniature boilers, including reinstalled boilers must be installed in accordance with the requirements of the latest revision of the A.S.M.E. Boiler Construction Code and these rules and regulations. D. Upon completion of the installation, all miniature boilers shall be inspected by the chief inspector, a deputy inspector or a special inspector. At the time of this inspection, all miniature boilers must be stamped with the serial number of the city, followed by the letters "MFS," such letters and figures to be not less than 5/16 inch in height. (Code 1967, § 45-84; Code 1985, § 42-89)

Memphis Code of Ordinances § 14-12-55 Miniature boilers—Existing installations.

Sec. 14-12-55. - Miniature boilers—Existing installations. A. Application of section. This section shall apply to existing miniature boilers. B. Maximum allowable working pressure. Rules and regulations, as adopted for power boilers applying to strength of materials and calculations to determine maximum allowable working pressure, shall be used for miniature boilers unless a special rule is stated herein. The maximum allowable working pressure on the shell of a boiler or drum shall be determined by the provisions of section 14-12-52. C. Construction. The construction of miniature boilers, including factors of safety, except where otherwise specified, shall conform to that required for power boilers. D. Safety valves. Each miniature boiler shall be equipped with a sealed, spring-loaded, pop type safety valve not less than one-half-inch pipe size, connected directly to the boiler. The safety valve shall be plainly marked by the manufacturer showing name or identifying trademark, nominal diameter and pressure at which it is set to release. The safety valve relieving capacity of each boiler shall be such that it will discharge all the steam that can be generated by the boiler without allowing the pressure to rise more than six percent above the maximum allowable working pressure. In those cases where the boiler is supplied with feed water directly from a pressure main or system without the use of a mechanical feeding device, the safety valve shall be set to release at a pressure not in excess of 94 percent of the lowest pressure obtained in the supply main or system feeding the boiler. Return traps shall not be considered mechanical feeding devices. E. Gauge glass and water level indicator. Each miniature boiler shall be equipped with a water gauge glass for determination of the water level. The lowest permissible water level shall be at a point one-third of the height of the shell, except where the boiler is equipped with an internal furnace, in which case it shall be not less than one-third of the tube length above the top of the furnace. For small boilers where there is insufficient space for the usual type of gauge glass, water level indicators of the glass, bull's eye type may be used. F. Feeding and feed water piping. Every miniature boiler shall be provided with at least one feed pump or other mechanical feeding device except where the following conditions exist: 1. Where the boiler is connected to a water main or system having sufficient pressure to feed the boiler at any time while under pressure; 2. Where the fuel burned is such that all heat input can be discontinued instantaneously by the operation of a valve, cock or switch, thereby permitting the boiler pressure to be quickly lowered to a point where water can be introduced from the connection to the water main; 3. Where the boiler is operated without extraction of steam (closed system) in which case the boiler is filled, when cold, through the connection or opening provided in accordance with the following rule. Each miniature boiler shall be fitted with a feed water connection which shall not be less than one-half-inch iron pipe size. The feed piping shall be provided with a check valve near the boiler and a valve or check between the check valve and the boiler. Feed water may be introduced through the blow-off connection where the boiler is operated without extraction of steam (closed system). Feed water shall not be introduced through the water column or gauge glass connections while the boiler is under pressure. G. Blow-off pipe. Each miniature boiler shall be provided with a blow-off connection, not less than one-half-inch iron pipe size, directly connected with the lowest water space. Blow-off piping shall not be galvanized and shall be provided with a valve or cock. H. Steam gauges. Each miniature boiler shall be equipped with a steam gauge having a dial range not less than 1½ times the maximum allowable working pressure. The gauge shall be connected to the steam space or to the steam connection to the gauge glass by a brass or bronze composition siphon tube or equivalent device that will keep the gauge tube filled with water. I. Stop valves. The steam piping from a miniature boiler shall be provided with a stop valve located as close to the boiler shell or drum as is practicable, except in those classes where the boiler and steam receiver are operated as a closed system. J. Gas burners. For installations which are gas-fired, the burners used shall conform to the requirements of the American Gas Association, as stated in the appendix of the A.S.M.E. Boiler Construction Code, section V. K. Flue connection. Each gas-fired boiler shall be equipped with at least four-inch vent pipe or flue, in no case less than the vent outlet from the boiler extended to and approved location outside the building or connected to a chimney flue. Where the horizontal run is more than ten feet the vent shall be increased to six inches. A draft hood of approved design shall be provided on each boiler. L. Stamping of boilers. Each boiler shall be stamped with a serial number of the city, followed by the letters "MFS," such letters and figures to be not less than 5/16 inch in height The stamping shall not be concealed by lagging or paint and shall be exposed at all times. (Code 1967, § 45-85; Code 1985, § 42-90)

Memphis Code of Ordinances § 14-12-56 Heating boilers—New installations.

Sec. 14-12-56. - Heating boilers—New installations. A. No heating boiler, except reinstalled boilers and those exempted by these rules and regulations, shall hereafter be installed in this city unless it has been constructed, inspected and stamped in conformity with section 4 of the A.S.M.E. Boiler Construction Code and is approved, registered and inspected in accordance with the requirements of these rules and regulations. B. All new heating boiler installations, including reinstalled boilers, must be installed in accordance with the requirements of the latest revision of the A.S.M.E. Boiler Construction Code and these rules and regulations. C. Upon completion of the installation, all boilers shall be inspected by the chief inspector, a deputy inspector or a special inspector. At the time of this inspection, all steel heating boilers must be stamped with the serial number of the city, followed by the letters "MFS," such letters and figures to be not less than 5/16 inch in height. All cast iron heating boilers shall have securely attached to the front of the boiler a metal tag not less than one inch in height, which shall have the serial number of the city stamped thereon. D. It is recommended that the return water connections to all low pressure steam heating boilers supplying a gravity return heating system be so arranged as to form what is known as the "water line return" so that the water cannot be forced out of the boiler below the safe water level. This connection is shown in Figure H-3, section 4, A.S.M.E. Boiler Construction Code. (Code 1967, § 45-86; Code 1985, § 42-91)

Memphis Code of Ordinances § 14-12-57 Existing installations.

Sec. 14-12-57. - Existing installations. A. Application of section. This section shall apply to existing heating boilers. B. Maximum allowable working pressure in A.S.M.E. Code boilers. The maximum allowable working pressure of a boiler built in accordance with the A.S.M.E. Code shall in no case exceed the pressure indicated by the manufacturer's identification stamped or cast upon the boiler or upon a place secured to it. C. Maximum allowable working pressure for non-code riveted boilers. The maximum allowable working pressure on the shell of a noncode riveted heating boiler shall be determined in accordance with the provisions of this article for covering existing installations power boilers, except that in no case shall the maximum allowable working pressure of a steam heating boiler exceed 15 pounds or a hot water boiler exceed 160 pounds at a temperature not exceeding 250 degrees Fahrenheit. D. Maximum allowable working pressure for non-code welded boilers. The maximum allowable working pressure of a noncode steel or wrought iron heating boiler of welded construction shall not exceed 15 pounds. For other than steam service the maximum allowable working pressure shall be calculated in accordance with section IV of the A.S.M.E. Code. E. Maximum allowable working pressure for noncode cast iron boilers. The maximum allowable working pressure of a noncode boiler composed principally of cast iron shall not exceed 15 pounds for steam service or 30 pounds for hot water service. The maximum allowable working pressure of a noncode boiler having cast iron shell or heads and steel or wrought iron tubes shall not exceed 15 pounds for steam service or 30 pounds for water service. F. Fired radiators. A radiator in which steam pressure is generated at a pressure of 15 pounds or less is considered a low pressure boiler. G. Procedure if operation unsafe at previously approved pressure. If in the judgment of the inspector a steam heating boiler is unsafe for operation at the pressure previously approved, the pressure shall be reduced, proper repair made or the boiler retired from service. H. Safety valves. Each steam heating boiler shall be provided with one or more officially rated safety valves of the spring-pop type adjusted and sealed to discharge at a pressure not to exceed 15 pounds per square inch. The installation, size and capacity of the safety valves shall conform to the requirements of the A.S.M.E. Heating Boiler Code. I. Water relief valves. Each hot water heating boiler shall have at least one officially rated pressure relief valve set to relieve at or below the maximum allowable working pressure of the boiler. Each hot water supply boiler shall have at least one officially rated pressure temperature relief valve of the automatic-reseating type set to relieve at or below the maximum allowable working pressure of the boiler. The installation, size and capacity of the relief valves shall conform to the requirements of the A.S.M.E. Heating Boiler Code. J. Steam gauge. Each steam boiler shall have a steam pressure gauge connected to the steam space of the boiler itself or on steam pipe near the boiler. The graduations of the steam gauge shall not be less than 15 pounds nor more than 30 pounds. K. Water gauge glass and gauge cocks. Each steam boiler shall have at least one water gauge glass with the lowest visible part above the heating surfaces in the primary combustion chamber. When, in the judgment of an inspector, the heating surfaces above the low water line may be injured by contact with gases or high temperature the water gauge glass shall be raised until the lowest visible part of the gauge glass is above such heating surface. Each steam boiler shall have two or more gauge cocks located within the visible length of the water gauge glass, except when such boiler is provided with two water gauge glasses. L. Stop valves and check valves. If a boiler may be closed off from the heating system by closing a steam stop valve, there shall be a check valve in the condensate return line between the boiler and the system. If any part of a heating system may be closed off from the remainder of the system by closing a steam stop valve, there shall be a check valve in the condensate return pipe between the boiler and the system. M. Feed water connections. Feed water connections shall be independent of any water gauge connections and be made to the condensate return pipe or reservoir of the condensate return pump. There should be a stop valve and a check valve in the feed water line at the boiler. N. Return pump. Each condensate return pump where practicable shall be provided with an automatic water level control set to maintain the water level within the limits of two gauge cocks. O. Repairs and renewals of fittings and appliances. Whenever repairs are made to fittings or appliances or it becomes necessary to replace them, the work must comply with the provisions of this chapter for new installations. P. Stamping of existing heating boilers. Each steel heating boiler shall be stamped with a serial number of the city, followed by the letters "MFS," such letters and figures to be not less than 5/16 inch in height. The stamping shall not be concealed by flagging or paint and shall be exposed at all times. Each cast iron heating boiler shall have securely attached to the front of the boiler a metal tag not less than one inch in height, which shall have the serial number of the city stamped thereon. (Code 1967, § 45-87; Code 1985, § 42-92; Ord. No. 1427, § 1(4), (5), 8-29-1972)

Memphis Code of Ordinances § 14-12-58 Unfired pressure vessels—New installations.

Sec. 14-12-58. - Unfired pressure vessels—New installations. A. No unfired pressure vessel, except reinstalled vessels and those exempt by these rules and regulations, shall hereafter be installed in this city unless it has been constructed, inspected and stamped in conformity with section 8 of the A.S.M.E. Boiler and Unfired Pressure Vessel Construction Code and is approved, registered and inspected in accordance with the requirements of these rules and regulations. B. All new installation unfired pressure vessels, including reinstalled unfired pressure vessels, shall be installed in accordance with the requirements of the latest revision of the A.S.M.E. Boiler and Unfired Pressure Vessel Construction Code, section 8, and these rules and regulations. C. An unfired pressure vessel having the standard stamping of a state that has adopted a standard of construction equivalent to the standard of these rules may be accepted by the chief inspector; provided, however, that, the person desiring to install the same shall make application for the installation and shall file with this application the manufacturer's data report covering the construction of the unfired pressure vessel in question. D. Upon completion of the installation, all unfired pressure vessels shall be inspected by the chief inspector, a deputy inspector or a special inspector. At the time of this inspection each unfired pressure vessel shall be stamped with a serial number of the city followed by the letters "MFS," such letters and figures to be not less than 5/16 of an inch in height. The stamping shall not be concealed by lagging or paint and shall be exposed at all times. E. Rupture discs or safety heads may be used for additional protection of pressure vessels. (Code 1967, § 45-88; Code 1985, § 42-93)

Memphis Code of Ordinances § 14-12-59 Unfired pressure vessels—Existing installations.

Sec. 14-12-59. - Unfired pressure vessels—Existing installations. A. Application of section. This section applies to existing unfired pressure vessel installations. B. Maximum allowable working pressure for standard unfired pressure vessels. The maximum allowable working pressure for standard unfired pressure vessels shall be determined in accordance with the applicable provisions of the edition of the A.S.M.E. Code under which they were construed and stamped. C. Maximum allowable working pressure for nonstandard unfired pressure vessels. 1. For internal pressure. The maximum allowable working pressure on the shell of a nonstandard pressure vessel shall be determined by the strength of the weakest course computed from the thickness of the plate, the tensile strength of the plate, the efficiency of the longitudinal joint, the inside radius of the course and the factor of safety allowed by these rules. TS × T × E = Maximum allowable working pressure. R × FS = Pounds per square inch. TS = Ultimate tensile strength of shell plate pounds per square inch. When the tensile strength is not known it shall be taken as 55,000 pounds per square inch for temperatures not exceeding 700 degrees Fahrenheit. T = Minimum thickness of shell plate of weakest course, inches. E = Efficiency of longitudinal joint depending upon construction. Use valves as follows: For Riveted Joints Calculated riveted efficiency. For Fusion Welded Joints Single lap weld | 40% Double lap weld | 60% Single butt weld | 50% Double butt weld | 70% Forge weld | 70% Brazed steel | 80% Brazed copper | 90% R = Inside radius of weakest course of shell, inches, provided the thickness does not exceed ten percent of the radius. If the thickness is over ten percent of the radius, the outer radius shall be used. FS = Factor of safety allowed by these rules. 2. For external pressure. The maximum allowable working pressure for cylindrical vessels subjected to external or collapsing pressure shall be determined by the rules in Paragraphs U-120 to U-138 inclusive of the A.S.M.E. Boiler and Unfired Pressure Vessel Construction Code, section 8. D. Factors of safety. The minimum factor of safety shall in no case be less than four for vessels up to and including 20 years of age and shall be not less than four and one-half where the age of the vessel is more than 20 years. These factors of safety may be increased when deemed necessary by the inspector to insure the operation of the vessel within safe limits. The condition of the vessel and the particular service it is being subjected to will be the determining factor. E. Inspection of inaccessible parts. Where, in the opinion of the inspector, as the result of conditions disclosed at an inspection, it is advisable to remove interior or exterior lining, covering or brick work to expose certain parts of the vessel not normally visible, the owner or user shall remove such material to permit proper inspection and the drilling of any part of the vessel where necessary to ascertain thickness. F. Safety appliances. Each unfired pressure vessel shall be protected by such safety and relief valves and indicating and controlling devices as will insure its safe operation. These valves and devices shall be so constructed, located and installed that they cannot readily be rendered inoperative. The relieving capacity of safety valves shall be such as to prevent a rise of pressure in the vessel of more than ten percent above the maximum allowable working pressure taking into account the effect of static head. Safety valve discharges shall be carried to a safe place. G. Rupture discs. Rupture discs or safety heads may be used for additional protection of unfired pressure vessels. H. Repairs and renewals of fittings and appliances. Whenever repairs are made to fittings and appliances or it becomes necessary to replace them, the work must comply with this chapter. I. Stamping of existing unfired pressure vessels. Each unfired pressure vessel shall be stamped with a serial number of the city followed by the letters "MFS," such letters and figures to be not less than 5/16 inch in height. The stamping shall not be concealed by lagging or paint and shall be exposed at all times. (Code 1967, § 45-89; Code 1985, § 42-94)

Memphis Code of Ordinances § 14-12-60 General requirements.

Sec. 14-12-60. - General requirements. A. Inspections generally. All boilers and unfired pressure vessels, unless otherwise exempt by these rules and regulations and which are subject to regular inspection as provided for in section 14-12-24, shall be prepared for such inspection, or hydrostatic tests whenever necessary or by the owner or user when notified by the chief inspector, deputy inspector or special inspector. The owner or user shall prepare each boiler or unfired pressure vessel for internal inspection and shall prepare for and apply the hydrostatic test whenever necessary, on the date specified by the chief inspector, deputy inspector or special inspector, which date shall not be less than seven days after the date of notification. B. Preparation for internal inspection. The owner or user shall prepare a boiler for internal inspection in the following manner: 1. Water shall be drawn off and the boiler thoroughly washed. 2. All manhole and handhole plates, wash-out plugs and plugs in water column connection shall be removed, the furnace and combustion chambers thoroughly cooled and cleansed. 3. All grates of internally fired boilers shall be removed. 4. At each annual inspection, brick work shall be removed as required by the inspector in order to determine the condition of the boiler, headers, furnace, supports or other parts. 5. The steam gauge shall be removed for testing. 6. Any leakage of steam or hot water into the boiler shall be cut off by disconnecting the pipe or valve at the most convenient point. Unfired pressure vessels shall be prepared for inspection to the extent deemed necessary by the inspector. C. Improper preparation for inspection. If a boiler or unfired pressure vessel has not been properly prepared for an internal inspection or the owner or user fails to comply with the requirements for hydrostatic tests as set forth in these rules, the inspector may decline to make the inspection or test and the certificate of inspection shall be withheld until the owner or user complies with the requirements. D. Removal of covering to permit inspection. If the boiler or unfired pressure vessel is jacketed so that the longitudinal seams of shells, drums or domes cannot be seen, enough of the jacketing, setting wall or other form of casing or housing shall be removed so that the size of the rivets, pitch of the rivets and other data necessary to determine the safety of the boiler or unfired pressure vessel may be obtained, provided such information cannot be determined by other means. E. Lap seam cracks. The shell or drum of a boiler in which a lap seam crack is discovered along a longitudinal riveted joint shall be immediately discontinued from use. If the boiler is not more than 15 years of age, a complete new course of the original thickness may be installed at the discretion of the inspector (and after approval by the chief inspector). Patching is prohibited. (By "lap seam crack" is meant the typical crack frequently found in lap seams, extending parallel to the longitudinal joint and located either between or adjacent to rivet holes.) F. Hydrostatic pressure tests. A hydrostatic pressure test, when applied to boilers or unfired pressure vessels of riveted or welded construction, except locomotive boilers, shall not exceed 1½ times the maximum allowable working pressure. Hydrostatic pressure applied to locomotive boilers shall not exceed 1¼ times the maximum allowable working pressure. During the hydrostatic pressure test, the safety valve or valves shall be removed or each valve disc shall be held down by means of a testing clamp and not by applying additional load to the spring with the compression screw. It is suggested that the minimum temperature of the water used to apply a hydrostatic test be not less than 70 degrees Fahrenheit but the maximum temperature shall not exceed 160 degrees Fahrenheit. Note: When a hydrostatic test is to be applied to existing installations, the pressure shall be as follows: 1. For all cases involving the question of tightness, the pressures shall be equal to the release pressure of the safety valve or valves having the lowest release setting. 2. For all cases involving the question of safety, the pressure shall be equal to 1½ times the maximum allowable working pressure, except for locomotive boilers, in which case it shall be 1¼ times the maximum allowable working pressure. G. Low water fuel cut-offs. All automatically-fired steam or vapor boilers shall be equipped with an automatic low-water fuel cut-off and water feeding device so constructed that the water inlet valve cannot feed water into the boiler through the float chamber, and so located as to automatically cut off the fuel supply and/or supply requisite feedwater when the surface of the water falls to the lowest safe water line. This point should be not lower than the bottom of the water glass. Such a fuel or feedwater control device may be attached direct to a boiler or to the tapped openings provided for attaching a water glass direct to a boiler, provided that such connections from the boiler are nonferrous tees or Ys not less than one-half-inch pipe size between the boiler and the water glass so that the water glass is attached direct and as close as possible to the boilers; the straightway tapping of the Y or tee to take the water glass fittings, the side outlet of the Y or the tee to take the fuel cut-off or waterfeeding device. The ends of all nipples shall be reamed to full size diameter. Designs embodying a float and float bowl shall have a vertical straightway drainpipe at the lowest point in the water equalizing pipe connections by which the bowl and the equalizing pipe can be flushed and the device tested. H. Safety appliances. No person shall remove or tamper with any safety appliances prescribed by these rules except for the purpose of making repairs. The resetting of safety appliances shall be done in the presence of an authorized inspector. I. Blow-off tanks. Blow-off piping from a power boiler or a miniature boiler shall not discharge directly into a sewer. A blow-off tank shall be used where conditions do not provide an adequate and safe open discharge. Blow-off tanks hereafter installed, if of metal, shall have a plate thickness of not less than 5/16 inch and shall be designed for a minimum working pressure of 50 pounds per square inch gauge. The outlet from the blow-off tank shall be twice the area of the inlet pipe and made to extend internally within eight inches from the bottom of the tank. A vent pipe at least four times the area of the inlet pipe shall lead to the outer atmosphere. Vents shall be as direct as possible to the outer air and discharge at a safe location. There shall be no valve or other possible obstructions, such as water pockets, between the tank and the discharge end of the vent pipe. All pipe connections between the tank and the boiler shall be as direct as possible and shall conform to Paragraph P-229, A.S.M.E. Boiler Construction Code. For convenience in cleaning the tank, a manhole or an access opening shall be provided. Where a blow-off tank is not vented as specified above, it shall be constructed for a pressure equal to that allowed on the boiler to which it is attached or shall be equipped with a safety valve or valves of sufficient capacity to prevent the pressure from exceeding the safe working pressure of the tank. As an alternate to the above, blow-off facilities may conform to the provisions set forth in the pamphlet titled, "Boiler Blow-Off Equipment," published by the National Board of Boiler and Pressure Vessel Inspectors, whose address is 1155 N. High St., Columbus, Ohio. J. Location of blow-offs. The discharge of safety valves, blow-off pipes and other outlets shall be located so as to prevent injury to personnel. K. Pressure reducing values. Where pressure reducing valves are used, one or more relief or safety valves shall be provided on the low pressure side of the reducing valve in case the piping or equipment on the low pressure side does not meet the requirements for the full initial pressure. The relief or safety valves shall be located adjoining to or as close as possible to the reducing valve. Proper protection shall be provided to prevent injury or damage caused by the escaping steam from the discharge or relief or safety valves if vented to the atmosphere. The combined discharge capacity of the relief valves shall be such that the pressure rating of the lower pressure piping or equipment shall not be exceeded in case the reducing valve sticks open. The use of hand-controlled by-passes around reducing valves is permissible. The by-pass, if used around a reducing valve, shall not be greater in capacity than the reducing valve unless the piping or equipment is adequately protected by relief valves or meets the requirements of the high pressure system. It is mandatory that a pressure gauge be installed on the low pressure side of a reducing valve. L. Electric steam generators. All electric steam generators shall be grounded in accordance with the city electrical code. A suitable screen or guard shall be provided around high tension bushings and a sign posted warning of high voltage. This screen or guard shall be so located that it will be impossible for anyone working around the generator to accidentally come in contact with the high tension circuits. When adjusting safety valves, the power circuit to the generator shall be open. The generator may be under steam pressure, but the power line shall be open while the operator is making the necessary adjustments. Each kw of electrical energy consumed by an electric steam generator operating at maximum rating shall be considered the equivalent of one square foot of heating surface of a fire tube boiler when determining the required amount of safety valve capacity. M. Major repairs. Where a major repair is necessary, an inspector shall be called for consultation and advice as to the best method of making such repair. After such repair is made it shall be subject to the approval of the inspector. Repairs to all boilers and unfired pressure vessels and their appurtenances, shall conform as nearly as practicable to the requirements of the National Board of Boiler and Pressure Vessel Inspectors. N. Repairs by fusion welding. When repairs are to be made wherein fusion welding is to be used, permission shall be obtained from the chief inspector, a deputy inspector or a special inspector and the welding shall be done in accordance with the rules recommended by the National Board of Boiler and Pressure Vessel Inspectors. O. Riveted patches. In applying riveted patches, the design of the patch and method of installation shall be in accordance with the rules for riveted patches recommended by the National Board of Boiler and Pressure Vessel Inspectors. P. Boiler room and clearance. When boilers are replaced or new boilers installed in either existing or new buildings, a minimum height of at least three feet shall be provided between the top of the boiler proper and the ceiling. All boilers shall be so located that two feet clearance around the boiler shall be provided for the proper operations of the boiler and its appurtenances, for the inspection of all surfaces, tubes, water walls, economizer, piping, valves and other equipment and for their necessary maintenance and repair. Every boiler hereafter installed in a building other than an industrial building, shall be located in a separate room or compartment and when not otherwise provided, shall be enclosed by fire walls or partitions as approved with floor and ceiling of fire resistant construction. Boiler and machinery rooms shall have proper ventilation, natural or mechanical, to insure adequate supply of fresh air to the boilers for proper combustion. When machinery emptying poisonous or noxious gases is located or operated in such rooms special precautions shall be provided for the safety of the attendants and occupants of the building. Q. Shop inspections. Any new power boiler being constructed for installation in the city shall be shop inspected in accordance with the provisions of the applicable section of the A.S.M.E. Boiler Code and shall be stamped A.S.M.E. and National Board. This shall not apply to low pressure heating boilers where shop inspection is not required by the A.S.M.E. Boiler Construction Code. Inspections made at the request of a boiler or tank manufacturer by the chief inspector or any deputy inspector shall be charged for at the rate of $25.00 for one-half day and $55.00 for one day plus all expenses, to include traveling, hotel and incidentals. This charge shall not void the regular charge or fee for inspection or certificate when the boiler is installed. R. Inspection of secondhand equipment. Charges for inspection of secondhand equipment shall be at the rate provided for in subsection Q of this section for shop inspections. S. Conditions not covered by rules. In any condition not covered by these rules, the A.S.M.E. Code for new installations shall apply. (Code 1967, § 45-90; Code 1985, § 42-95)

Source: City of Memphis, Code of Ordinances and Charter and Related Laws (Municode Library, library.municode.com)URL: https://library.municode.com/tn/memphis/codes/code_of_ordinances?nodeId=TIT14BUCO_CH14-12BOUNPRVECO_ART4RURERECOININMAUSFetched: 10/28/2026