Engineers* and Firemen's License Law Boiler Inspection Law Rules formulated by the Board of Boiler Rules BOSTON WRIGHT & POTTER PRINTING CO.. STATE PRINTERS 18 POST OFFICE SQUARE 1909 VVclS'S. . VfcW-S . sV«\v\\ft£ sAc THE COMMONWEALTH OF MASSACHUSETTS ENGINEERS' AND FIREMEN'S LICENSE LAW Boiler inspection Law Rules formulated by the Board of Boiler Rules BOSTON WRIGHT & POTTER PRINTING CO., STATE PRINTERS 18 POST OFFICE SQUARE 1909 D« OF D. JAN 25 1910. 'b ^ y \ fc / ^ 3 ft CONTENTS. Engineers' and Firemen's License Law, . Boiler Inspection Law, ...... Rules formulated by the Board of Boiler Rules, Recommendations made by the Board of Boiler Rules, Index to Rules, ....... PAGE v-viii . 1X-XT1 . 1-52 . 53, 54 . 55-67 ©f)e Comtnontoealit) of fflaBmttyimttz. ENGINEERS' AND FIREMEN'S LICENSE LAW. Sections 78 to 86 inclusive of Chapter 102 of the Eevised Laws and Amendments relative to the Licensing of Engineers and Firemen. Section 78. (As amended ly chapter 373, Acts of 1907, talcing effect September 1, 1907.) ~No person shall have charge of or operate a steam boiler or engine in this commonwealth, except boilers and License re- engines upon locomotives, motor road vehicles, boilers and quire engines in private residences, boilers in apartment houses of less than five flats, boilers and engines under the jurisdiction of the United States, boilers and engines used for agricultural purposes exclu- certain sively, boilers and engines of less than eight horse power, e ngines a ex- and boilers used for heating purposes exclusively which are emp ' provided with a device approved by the chief of the district police limit- ing the pressure carried to fifteen pounds to the square inch, unless he holds a license as hereinafter provided. The owner or user Owner or of a steam boiler or engine, other than boilers or engines user allowed one week, above excepted, shall not operate or cause to be operated a steam boiler or engine for a period of more than one week, unless the person in charge of and operating it is duly licensed. Section 79. If such steam engine or boiler is found to be in charge of or operated by a person who is not a duly licensed engineer or fire- man and, after a lapse of one week from such time, it is Evidence of again found to be operated by a person who is not duly v ° a 10n " licensed, it shall be deemed prima facie evidence of a violation of the provisions of the preceding section. Section 80. The words " have charge " or " in charge", in the two preceding sections, shall designate the person under whose supervision a boiler or engine is operated. The person operating shall v, A j. 1 f* a n i 4- 11 Designation. be understood to mean any and all persons who are actually engaged in generating steam in a power boiler. vi Revised Laws, Chap. 102. — Sects. 81, 82. Section 81. (As amended by chapter 310, Acts of 1905.) Whoever Application desires to act as engineer or fireman shall apply for a license o e ma e. therefor to the examiner of engineers for the city or town in which he resides or is employed, upon blanks to be furnished by the Application examiner. The application shall be accompanied by a fee of one dollar and shall show his total experience. Wilful a si ca on. f a i s ifi ca ti n in the matter of statements contained in the application shall be deemed sufficient cause for the revocation of said Practical ex- license at any time. The applicant shall be given a practi- amma ion. cg j exam j na ti n and, if found competent and trustworthy, he shall receive, within six days after the examination, a license graded according to the merits of his examination, irrespective of the grade of license for which he applies. The applicant shall have the privilege of having one person present during his examination, who shall take no Ninety days part in the same, but who may take notes if he so desires. tween P exam- No person shall be entitled to receive more than one exami- ma ions. nation within ninety days, except in the case of an appeal as hereinafter provided. A license shall continue in force for three years, or until it is revoked for the incompetence or untrustworthiness of the licensee ; and a license shall remain revoked until a new license Renewal of is granted. A license, unless revoked, shall be renewed by license. an exam j ner f engineers upon application and without ex- amination, if the application for renewal is made within six months after its expiration. If a new license of a different grade is issued, the old license shall be destroyed in the presence of the exam- iner- If a license is lost by fire or other means, a new license shall be issued in its place, without re-examination of the licensee, upon satisfactory proof of such loss to an examiner. Section 82. (As amended by chapter 373, Acts of 1907, taking effect September 1, 1907.) Licenses shall be granted according to the com- ciassmcation petence of the applicant and shall be distributed in the fol- of licenses. lowing classes: — Engineers' licenses: — First class, to have charge of and operate any steam plant. Second class, to have charge of and operate a boiler or boilers, and to have charge of and operate engines, no one of which , shall exceed one hundred and fifty horse power, or to operate a first class plant under the engineer in direct charge of the plant. Third class, to have charge of and operate a boiler or boilers not exceeding in the aggregate one hundred and fifty horse power, and an engine not exceeding fifty horse power, or to oper- ate a second class plant under the engineer in direct charge of the plant. Fourth class, to have charge of and operate hoisting and por- table engines and boilers. Firemen's licenses: — Extra first class, to have charge of and operate any boiler or boilers. First class, to have Revised Laws, Chap. 102. — Sects. 83-85. vii charge of and operate any boiler or boilers where the pressure carried does not exceed twenty-five pounds to the square inch, or to operate high pressure boilers under the engineer or fireman in direct charge thereof. Second class, to operate any boiler or boilers under the engi- neer or fireman in direct charge thereof. Any person holding a first class or second class fireman's license at the time of the passage of this act shall receive a first class fireman's license under this act. A person holding an extra first or first class fireman's license may operate a third class plant under the engineer in direct charge of the plant. A person holding an engineer's or fireman's license who desires to special have charge of or to operate a particular steam plant or lcense# type of plant may, providing he holds an engineer's or fireman's license, if he files with his application a written request signed by the owner or user of said plant for such examination, be examined as to his compe- tence for such service and no other, and if found competent and trust- worthy shall be granted a license for such service and no . . . Limitation. other. No special license shall be granted to give any per- son charge of a plant over one hundred and fifty horse power. Section 83. The horse power of a boiler shall be ascertained upon the basis of three horse power for each square foot of grate surface, for a power boiler, and on the basis of one and one-half horse Boiler horse power for each square foot of grate surface, if the boiler is power ratm e- used for heating purposes exclusively. The engine power shall be reck- oned upon a basis of a mean effective pressure of forty pounds Engine horse per square inch of piston for a simple engine ; fifty pounds power ratin e- for a condensing engine ; and seventy pounds for a compound engine, reckoned upon area of high pressure piston. Section 84. (As amended by chapter 373, Acts of 1907, taking effect September 1, 1907.) A person who is aggrieved by the action of an ex- aminer in refusing or revoking a license may appeal there- Appeal may from to the remaining examiners, three or more of whom be made - shall together act as a board of appeal, and shall have the power to hear the parties and pass upon the subjects of appeal. If appeal is taken it must be within one month after the decision of the examiner. The applicant may have the privilege of having one first class engineer present during the hearing of his appeal, but he shall take no part therein. The decision of the majority of such examiners so acting as a board of appeal shall be final if approved by the chief of the district police. Section 85. (As amended by chapter 373, Acts of 1907, taking effect September 1, 1907.) An engineer's or fireman's license, granted under the provisions of the seven preceding sections or the corre- License to be sponding provisions of earlier laws, shall be placed so as to posted - viii Revised Laws, Chap. 102. — Sect. 86. be easily read in a conspicuous place in the engine room or boiler room of the plant operated by the holder of such license. The person in Daily record charge of a stationary steam boiler upon which the safety e ep ' valve is set to blow off at more than twenty-five pounds pressure to the square inch, except boilers upon locomotives, motor road vehicles, boilers in private residences, boilers in apartment houses of less than five flats, boilers under the jurisdiction of the United States, boilers used for agricultural purposes exclusively, and boilers of less than eight horse power, shall keep a daily record of the boiler, its Records to be condition when under steam and all repairs made and work done on it, upon forms to be obtained upon application from the boiler inspection department. These records shall be kept on file and shall be accessible at all times to the members of the boiler inspec- tion department. Section 86. (As amended by chapter 310, Acts of 1905.) The boiler inspection department of the district police shall act as exam- Enforcement iners and enforce the provisions of the eight preceding an pena y. sec ^ ongj anc [ whoever violates any of the provisions of said sections shall be punished by a fine of not less than ten nor more than three hundred dollars or by imprisonment for not more than three months. A trial justice shall have jurisdiction of complaints for violations of the provisions of the eight preceding sections, and in such cases may impose a fine of not more than fifty dollars. All Authority of J * . . / ■ . state boiler members oi the boiler inspection department oi the district enter prem- police shall have authority in the pursuance of their duty to enter any premises on which a boiler or engine is situated, and any person who hinders or prevents or attempts to prevent any state boiler inspector from so entering shall be so liable to the penalty as specified in this section. Acts of 1907, Chap. 465. — Sect. 1. ix ^\)t Ccmtncntoealtl) of JttaBBacfyitBette, [Acts of 1907, Chapter 465.] ^N" ACT RELATIVE TO THE OPERATION AND INSPECTION OF STEAM BOILEES. Be it enacted, etc., as folloivs: Section 1 (as amended by chapter 563, Acts of -1908, and chapter 393, Acts of 1909). All steam boilers and their appurtenances, except boilers of railroad locomotives, motor road vehicles, boilers Boilers to be in private residences, boilers in public buildings and in inspected - apartment houses used solely for heating, and carrying pressures not exceeding fifteen pounds per square inch, and having less c rt { than four square feet of grate surface, boilers of not more DOil ers than three horse power, boilers used for horticultural and agricultural purposes exclusively, and boilers under the jurisdiction of the United States, shall be thoroughly inspected internally internal and externally at intervals of not over one year, and shall Ins P ectlon - not be operated at pressures in excess of the safe working pressure stated in the certificate of inspection hereinafter mentioned, which pressure is to be ascertained by rules established by the board of boiler rules, to be appointed as hereinafter provided; and shall be equipped with such appliances to insure safety of operation as shall be prescribed by said board. All such boilers installed after January first, nineteen hundred and eight, shall be so inspected when installed. A boiler in this commonwealth at the time of the passage of ftat^on'May this act, which does not conform to the rules of construe- be' ^stalled. 7 tion formulated by the board of boiler rules may be installed after a thorough internal and external inspection and hydrostatic pres- sure test by a member of the boiler inspection department of the dis- trict police, or by an inspector holding a certificate of competency as an inspector of steam boilers, as provided by section six of chapter four x Acts of 1907, Chap. 465. — Sects. 2-6. hundred and sixty-five of the acts of the year nineteen hundred and seven, and employed by the company insuring the boiler. The pres- sure allowed on such boilers is to be ascertained by rules formulated by the board of boiler rules. No certificate of inspection shall be granted on any boiler installed after May first, nineteen hundred and eight, which does not conform to the rules formulated by the board of boiler rules. [Approved May 14, 1909. Section 2. Whoever owns, or uses or causes to be used, any such Owner or user D °il er > unless the same is under the periodically guaranteed musTreport inspection of insurance companies authorized to insure boil- location. erg j n ^g commonwealth, shall annually report to the chief of the district police the location of such boiler. Section 3. All such boilers shall also be inspected externally at least once each year when in operation, and it shall be the duty of the inspector to observe the pressure of steam carried, and inspection the general condition of each boiler, and to ascertain if the safety valve, and the appliances for indicating the pressure of steam and level of water in the boiler, are in proper working order. No person shall remove or tamper with any safety appliance prescribed by the board of boiler rules, and no person shall in any manner load the safety valve to a greater pressure than that allowed by the certificate of inspection. Section 4. The inspection of boilers and appurtenances shall be made by the boiler inspection department of the district police, under the supervision of the chief inspector of boilers, or by in- by whom spectors of such insurance companies as have complied with made. the laws of the commonwealth and are authorized to insure steam boilers. Inspectors of boilers in the boiler inspection depart- ment hereafter appointed shall not be subject to the rules of the civil service commission requiring members of the district police to be of a certain height and weight, but shall be appointed solely on the basis of their ability and competency properly and thoroughly to inspect steam boilers. Section 5. No person shall act as an inspector of boilers which are insurance under the periodicallv guaranteed inspection of companies inspector to hold certm- that have complied with the laws of this commonwealth, petency. unless he holds a certificate of competency as hereinafter provided. Section 6. Whoever desires to act as an inspector of boilers, as specified in section five, shall make application upon blanks to be fur- nished by the chief of the district police. Three members Insurance inspector to of the boiler inspection department shall act as a board of examiners. The application shall show the total experi- Acts of 1907, Chap. 465. — Sects. 7-9. xi ence of the applicant and shall be accompanied by a letter of request for his examination from the boiler insurance company by whom he is or is to be employed. Wilful falsification in the matter of . . Certificate any statement contained in the application shall be deemed may be re- sufficient cause for the revocation of said certificate at any time. The applicant shall be examined as to his knowledge of the construction, installation, maintenance and repair of steam subjects of boilers and their appendages, and, if found competent, he examinatl0n - shall receive a certificate of competency to inspect steam boilers for the boiler insurance company by whom he is or is to be employed, and the certificate shall continue in force during his employment by said com- pany, unless revoked for incompetency or untrustworthiness. When a person ceases to be employed as an inspector by a boiler insurance com- pany the insurance company shall notify the chief of the district police of the matter, giving the reasons therefor. A period of ninety days shall elapse between the dates of examinations, except in the case of an appeal as hereinafter provided. The certificate of competency shall be revoked for the incompetence or untrustworthiness of the holder thereof, and shall remain revoked until a new certificate is issued. If a certifi- cate is lost by fire or other cause a new certificate shall be issued in its place, upon satisfactory proof of such loss, without re-examination. Section 7. A person who is refused a certificate of competency, or whose certificate is revoked, may appeal from such decision to the chief of the district police, who shall grant a rehearing of the Appeal may case by a board of five examiners, no one of whom shall bemade * have acted as an examiner in the former instance, whose decision shall be final if approved by the chief of the district police. The applicant shall have the privilege of having one representative of the boiler insur- ance company by whom he is or is to be employed present during an examination or the hearing of an appeal. Section 8. Any steam boiler insurance company which issues a certificate of inspection signed by an inspector who does not hold a certificate of competency may have its authority to insure Authority to steam boilers revoked by the commissioner of insurance for m l^ r De l)0ilers the commonwealth. Any person in the employ of a steam revoked - boiler insurance company who applies for a certificate of competency as an inspector of boilers before this act takes effect shall be authorized to inspect boilers until his application is passed upon by the proper authority. Section 9. The inspectors of the boiler inspection department of the district police shall make reports of all inspections and Reports of shall make such recommendations to the chief inspector of ors. boilers as they may deem expedient. xii Acts of 1907, Chap. 465. — Sects. 10-15. Section" 10. Every insurance company authorized to insure steam boilers within the commonwealth shall forward to the chief inspector Reports of °^ boilers, within fourteen days after each internal and ex- commnies ternal inspection of boilers herein required to be inspected, sector in ~ reports of all boilers so inspected by it. Such reports shall be made on blanks furnished by the chief inspector of boil- ers, and shall contain all orders made by the company regarding the boilers so inspected. Section 11. Every boiler insurance company shall report imme- insurance diately to the chief inspector of boilers the name of the to report can- owner or user and the location of every boiler herein re- fused boners, quired to be inspected, upon which they have cancelled or refused insurance, giving the reasons for so doing. Section 12. Boilers and their appurtenances used exclusively for heating purposes, but which are not herein required to be boilers may inspected, shall be provided with such appliances to insure be inspected. x ' x - 1 r safety as shall be prescribed by the board of boiler rules, and it shall be the duty of the boiler inspection department to inspect such boilers upon application of the owner. Section 13. The owner or user of a boiler herein required to be inspected which is not insured by a boiler insurance company, shall, uninsured after due notice, prepare the boiler for internal and ex- preifare^for ternal inspection, at the appointed time, by drawing the inspection. wa ter from the boiler and removing the manhole and hand- hole plates. The boiler inspection department shall give the owner at least fourteen days' notice to prepare boilers for this inspection, but shall not be required to give notice of external inspection. Section 14. The owner or user of a boiler inspected by the boiler inspection department shall pay to the inspector five dollars for each Fees for boiler internally and externally inspected, and two dollars inspection. ^ or eac ] 1 Y i s it f or external inspection. The inspector shall give receipts for the same, and shall pay all sums so received to the chief inspector of boilers, who shall pay the same to the treasurer of the commonwealth. Section 15. If, upon inspection the inspector finds the boiler to be in safe working order, with the fittings necessary to safety, and properly Certificate of set up, he shall issue to the owner or user thereof a certifi- imffsured ° n cate of inspection stating the maximum pressure at which boilers. ^ e ^ n er mav ^ e operated, as ascertained by the rules es- tablished by the board of boiler rules, and thereupon such owner or certificate user ma y operate the boiler mentioned in the certificate. wVen^ith- 11 ' If the inspector finds that the boiler is not in safe work- ing condition, or is not provided with fittings necessary to Acts of 1907, Chap. 465. — Sects. 16-20. xiii safety, or if the fittings are improperly arranged, he shall withhold his certificate nntil the boiler and its fittings are put in a condition to insure safety of operation, and the owner or user shall not operate the boiler, or cause it to be operated, until such certificate has been granted. Section" 16. Every boiler which has been inspected by the boiler inspection department shall be numbered either by stamping the number upon the boiler or by attaching a numbered boilers to be metal tag by a seal or otherwise to the boiler or its fittings. No person except a member of the boiler inspection department shall deface or remove any such number or tag. Section" 17. Insurance companies engaged in the business of in- specting and insuring steam boilers shall, after each internal and ex- ternal inspection, if they deem the boiler to be in safe work- certificate of ing condition, issue a certificate of inspection stating the iSsured° n ° n maximum pressure at which the boiler may be operated. oi ers * This maximum pressure shall be determined under the rules established by the board of boiler rules. Section" 18 (as amended by chapter 563, Acts of 1908). No insur- ance company shall issue a policy of insurance on a steam boiler for a longer period than three years. If a boiler is insured which . . . Insurance has not previously been inspected externally and internally companies ,. n „. i. • t n . shall inspect and a certificate oi inspection issued, the company so msur- within one ing shall forthwith notify the chief of the boiler inspection de- partment of the district police to that effect, and shall inspect such boiler internally and externally within one month after the insur- no insurance ance is effected. No insurance shall be effected on any boiler C n certain 6 installed after May first, nineteen hundred and eight, which 01 ers * does not conform to the rules formulated by the board of boiler rules. Section 19. The certificate of inspection issued by the boiler in- spection department, or by an insurance company, shall state the name of the owner or user, the location, size and number of the Form of cer- boiler, the date of inspection and the maximum pressure at ca e ' which the boiler may be operated, under the signature of the person who made the inspection, and shall also contain such quotations from the statutes as shall be deemed necessary by the board of certificate to boiler rules, and shall so be placed as to be easily read in e pos e ' the engine room or boiler room of the plant where the boiler is located, except that the certificate of inspection for a portable boiler shall be kept on the premises and shall be accessible at all times. Section 20. No person shall use, or cause to be used, a steam boiler, excepting boilers upon motor road vehicles, steam fire engines, boilers in private residences, or boilers under the jurisdiction of the Fusible United States, unless it is provided with a fusible safety plugs - xiv Acts of 1907, Chap. 465. — Sects. 21-25. plug made of lead or some other equally fusible material^ as specified by the rules to be established by the board of boiler rules. Section 21. The owner or user of any boiler herein required to be owner or inspected shall immediately notify the boiler inspection de- defective P ° r partment, if the boiler is being operated under the inspec- boiier. ^ on Q £ ^ a |. d e p ar t m ent, or the insurance company, if it is being operated under its inspection, in case a defect affecting the safety of the boiler is discovered. Section 22. If the insurance on any boiler herein required to be Owner or inspected expires, or is cancelled because the insurers deem operate boSer it unsafe to continue the operation of the boiler, the owner exp?re1s r or C fs or user shall cease to operate it until it has been put in a canceiie . ga ^ e conc [ition, satisfactory to the insurers, or has been in- spected by the boiler inspection department and a certificate of inspec- tion has been issued. Section 23. If, in the judgment of the inspector or of the insurance Hydrostatic company, it is advisable to apply a hydrostatic pressure test pressure test. ^ Q a j^i^ ^he owner or user shall prepare the boiler for such test, as directed by the inspector or by the insurance company. Section 24. The governor, within thirty days after the passage of Board of this act, with the consent of the council, shall appoint a board of five persons, to be known as the Board of Boiler Eules, of whom the last four shall be appointed to serve as follows : — Appoint- Two for a term of two years each and two for a term of three years each. At the expiration of their terms of office their successors shall be appointed for terms of three years each. The members of the board, other than the chairman hereinafter designated, shall receive for their services the first year in office the sum of five hundred dollars each. Thereafter they shall receive as compensation for their services and reimbursement for their expenses such amount as the governor and council shall order, not exceeding in the aggregate in any one year the sum of one thousand dollars. The board shall be con- stituted as follows : — The chief inspector of the boiler inspection de- partment of the district police, who shall be its chairman ; one member representing the boiler using interests; one member representing the boiler manufacturing interests; one member representing the boiler in- surance interests ; and one member who is an operating engineer. Section 25. The chief inspector of boilers of the boiler inspection department of the district police shall appoint a clerk, who shall be a cierk, ap- stenographer, and who shall also act as secretary of the ]j° c intment ' board of boiler rules, and whose salary shall be twelve hun- dred dollars a year. The necessary expenses of the board, including those of the secretary of the board, incurred in the discharge Acts of 1907, Chap. 465. — Sects. 26, 27. xv of their duty during the first year, shall be paid out of the treasury of the commonwealth, but shall not exceed the sum of fifteen hundred dollars for that year. The attorney-general of the commonwealth shall furnish all needed assistance to the board in the framing of the rules hereinafter provided for. Sectiox 26 (as amended by chapter 393, Acts of 1909). It shall be the duty of the board of boiler rules to formulate rules for the con- struction, installation and inspection of steam boilers, and D .. for ascertaining the safe working pressure to be carried on |JJ5Y d of i , said boilers, to prescribe tests, if they deem it necessary, to ascertain the qualities of materials used in the construction of boilers; to formulate rules regulating the construction and sizes of safety valves for boilers of different sizes and pressures, the construction, use and location of fusible safety plugs, appliances for indicating the pressure of steam and the level of water in the boiler, and such other appliances as the board may deem necessary to safety in operating steam boilers ; and to make a standard form of certificate of inspection. The board of boiler rules shall hold public hearings on the first Thurs- Board of day in May and November of each year, and at such other toH2id U pub- times as the board may determine, on petitions for changes bearings, in the rules formulated by said board. If the board, after any such hearing, shall deem it advisable to make changes in said rules, it shall appoint a day for a further hearing, and shall give notice thereof and of the changes proposed by advertising in at least one newspaper in each of the cities of Boston, Worcester, Springfield, Fall Eiver, Lowell and Lynn, at least ten days before said hearing. If the board on its own initiative contemplates changes in said rules, like notice and a hearing shall be given and held before the adoption thereof. Changes made in the rules which affect the construction of new boilers shall take effect six months after the approval of rules, when the same by the governor: provided, hoivever, that the board may, upon request, permit the application of such change in, or additions to, rules, to boilers manufactured or installed during said six months. When a person desires to manufacture a special type of boiler the design of which is not covered by the rules formulated by the board of boiler rules, he shall submit of boilers may drawings and specifications of such boiler to said board, which, if it approves, shall permit the construction of the same. [Ap- proved May 14, 1909. Section 27. The rules so formulated shall be submitted to the governor for his approval, and when approved shall have i • -. i 1 ii i • tip -in Rules t0 De the force of law, and shall be printed and furnished to approved by ,-i i i n •! • i- i the governor. those requesting them by the boiler inspection department. xvi Acts of 1907, Chap. 465. — Sects. 28-30. Section 28 (as amended by chapter 393, Acts of 1909). The boiler inspection department of the district police shall enforce the provisions of the preceding sections and such rules as shall be promulgated by the board of boiler rules with the approval of the governor. "Whoever violates any provision of this act or of the said rules shall be punished by a fine of not less than twenty nor more than five hundred dollars or by imprisonment for not more than six months, or by both such fine and imprisonment. A trial justice shall have jurisdiction of complaints for violation of the provisions of this act, and in such cases may impose a fine of not more than fifty dollars. All members of the boiler inspection Authority of . state boiler department ol the district police shall have authority in inspectors to . . enter prem- the pursuance of their duty to enter any premises on which a boiler is situated, and any person who hinders or prevents or attempts to prevent any member of the boiler inspection department from so entering shall be liable to the penalty specified in this section. The provisions of this act relative to the inspection and exempt in operation of boilers within the commonwealth shall not be held to apply to steam fire engines brought into the com- monwealth for temporary use in times of emergency, for the purpose of checking conflagrations. [Approved May 14, 1909. Acts incon- Section 29. All acts and parts of acts inconsistent here- sistentre- in i n pealed. with are hereby repealed. Sectiok 30. The last sentence of section four, and sections twenty- four to twenty-seven, inclusive, shall take effect upon the passage of When to take this act. In all other respects the act shall take effect on effect. ^ e g rg £ ^ a y o | Q c -t; 0Der j n the vear nineteen hundred and seven. But inspectors employed by boiler insurance companies may be examined, and certificates of competency as provided in sections six and seven may be granted at any time after the . passage of this act. [Approved May 29, 1907. She tJLotmnontoealtt} of ittasBcufyiisettB. Board of Boiler Rules, State House, Boston. Joseph H. McNeill, Cliief Inspector Boiler Inspection Department, Chairman. John A. Stevens, M.E., Representing Boiler-using Interests. Frederick H. Ketes, M.E., Representing Boiler-manufacturing Interests. Eobert J. Dunkle, Representing Boiler-insurance Interests. William M. Beck, Representing Operating Engineers. RULES FORMULATED BY THE BOARD OF BOILER RULES. [In accordance with the provisions of section 26, chapter 465, Acts of 1907, as amended hy chapter 393, Acts of 1909, " An Act relative to the operation and inspection of steam boilers."] The Rules previously issued and additions made thereto are arranged as follows : — Part I. These Rules, in addition to the Rules contained in Part II., apply to boilers installed on or before May 1, 1908. Part II. These Rules apply to all boilers now or hereafter in- stalled. Part III. These Rules, in addition to the Rules contained in Part II., apply to boilers installed after May 1, 1908. Part I. — Section 1. PAET I. These Rules, in addition to the Rules contained in Part II., apply to boilers installed on or before May 1, 1908. Section 1. 1. The maximum pressure to he allowed on a steel or mine wrought-iron shell or drum of a hoiler shall he determined allowable from the minimum thickness of the shell plates, the lowest tensile strength of the plates, the efficiency of the longi- tudinal joint, the inside diameter of the outside course and the lowest factor of safety allowed "by these rules, the formula "being : — m o \/ \\/ Of — — — — '° = maximum allowable working pressure per square inch, in * ' ' pounds. T.S. = tensile strength of shell plates, in pounds, t = minimum thickness of shell plates, in inches. % = efficiency of longitudinal joint, method of determining which is given in section 7, Part II. of these Rules. R = radius = one-half (J) the inside diameter of the outside course of the shell or drum. F.S. = lowest factor of safety allowed by these Rules. 2. When the tensile strength of steel or wrought-iron shell strength, plates is not known, it shall be taken as fifty-five thousand (55,000) pounds for steel and forty-five thousand (45,000) pounds for wrought iron. . . 3. The lowest factor of safety to be used for boilers, the Sfety. ° f longitudinal joints of which are of butt and double-strap con- struction, shall be four and five-tenths (4.5). Note. — Factors of safety which also apply to boilers installed before May 1, 1908, are specified in paragraph 7, section 1, Part II. of these Rules. 4. "When the diameter of the rivet holes in the longitudinal Rivets. . . ° joints of a boiler is not known, the diameter and cross-sec- tional area of rivets, after driving, shall be taken as follows : — Part I. — Section 1 . Thickness of plate, . y 4 // .25" % 2 " .28125" 5 /i«" .3125" .34375" %" .375" %" .375" 1 %2 // .40625" Diameter of rivet after driving. w Hie" %" %" %"up to and in- cluding 2" pitch. 13 /ie"over 2" pitch. 13 /l6" Cross-sectional areaof rivet after driving. .3712sq.in. .3712 sq.in. .4418 sq.in. .4418 sq.in. .4418 sq.in. .5185 sq.in. .5185 sq.in. Thickness of plate, 7 /i«" .4375" .4375" 15 / 32 " .46875" y 2 " .5" % 8 " .5625" %" .625" Diameter of rivet after driving. %"up to and including 2Vi"pitch. 15 /ie" over m" pitch. 15 /ic" 15 Ao" W ltte" Cross-sectional area of rivet after driving. .6013 sq. in. .6903 sq. in. .6903 sq.in. .6903 sq. in. .8866 sq. in. .8866 sq. in. 5. The minimum size of a safety valve (other than a direct spring-loaded safety valve) shall be governed by the pressure safety allowed, as stated in the certificate of inspection, and by the not spring- grate area of the boiler, subject to the following conditions and as shown by the table in paragraph 6 of this section. Condition A. — A single boiler, or two or more boilers connected to a common steam main and allowed the same pressure: the minimum size of safety valve for each boiler shall be governed by the pressure allowed, as stated in the certificate of inspection, and by the grate area of the boiler. Condition B. — When two or more boilers, which are allowed different pressures, are connected to a common steam main, the minimum size of each safety valve shall be governed by the pressure allowed, as stated in the certificate of inspection, and by the grate area of the boiler ; and all safety valves shall be set at a pressure not exceeding the lowest pressure allowed. The aggregate valve area shall not be less than that required for the aggregate grate area, based on the lowest pressure allowed, as shown by the table. Condition C. — When two or more boilers, which are allowed differ- ent pressures, are connected to a common steam main, and all safety valves are not set at a pressure not exceeding the lowest pressure allowed, the boiler or boilers allowed the lower pressures shall each be protected by a safety valve or valves placed on the connecting pipe to the steam main; the area or combined area of the safety valve or valves placed Single boilers, and boilers con- nected and allowed same pres- sure. Boilers connected and allowed different pressures. 4 Part I. — Section 1. on the connecting pipe to the steam main shall not be less than the area of the connecting pipe, except when the steam main is smaller than the connecting pipe, when the area or combined area of safety- valve or valves placed on the connecting pipe shall not be less than the area of the steam main. Each safety valve placed on the connecting pipe shall be set at a pressure not exceeding the pressure allowed on the boiler it protects. 6. A table of areas of grate surfaces, in square feet, for other than direct spring-loaded safety valves, follows : — Maximum Pressure allowed per Square Inch on the Boiler. Zero to 25 Pounds. Over 25 to 50 Pounds. Over 50 to 100 Pounds. Diameter of Valve, in Inches. Area of Valve, in Square Inches. Area of Grate, in Square Feet. 1 1V4 1% 2 2y 2 3 3% 4 4y a 5 .7854 1.2272 1.7671 3.1416 4.9087 7.0686 9.6211 12.5660 15.9040 19.6350 1.50 2.25 3.00 5.50 8.25 11.75 16.00 21.00 26.75 32.75 1.75 2.50 3.75 6.50 10.00 14.25 19.50 25.50 32.50 40.00 2.00 3.00 4.00 7.25 11.00 16.00 21.75 28.25 36.00 44.00 Bottom blow-ofl. 7. Each boiler shall have a bottom blow-off pipe, fitted with a valve or cock, in direct connection with the lowest water space practicable. Part II. — Section 1. PAKT II. These rules apply to all boilers now or hereafter installed. Section 1. 1. The pressure allowed on a boiler constructed wholly of cast iron shall not exceed twenty-five (25) pounds per square JJlfgJJJ.^ 111 inch. 2. The pressure allowed on a boiler, the tubes of which are secured to cast-iron headers, shall not exceed one hundred and sixty (160) pounds per square inch. 3. The pressure allowed on a boiler fitted with a district police lock-pop safety valve shall not exceed fifteen (15) pounds per square inch. This special type of safety valve is provided for by section 78, chapter 102 of the Revised Laws (Engineers' and Firemen's License Law), and applies to boilers used for heating purposes exclusively. 4. The resistance to crushing of mild steel shall be taken Crusning at ninety-five thousand (95,000) pounds per square inch of jSfdlteei° f cross-sectional area. 5. The maximum shearing strength of rivets per square shearing inch of cross-sectional area shall be taken as follows : — o/rSfets. Iron rivets in single shear, Iron rivets in double shear, Steel rivets in single shear, Steel rivets in double shear, Pounds. 38,000 70,000 42,000 78,000 6. The following table gives the allowable shearing strength of rivets from eleven-sixteenths (fj-) inch to one and one-sixteenth (1 T ^) inches in diameter, in pounds : — Diameter of rivet after driving, Hie" .6875" %" .75" 18 ,V .8125" V8 .875" 15 ,i«" .9375" Ui«" 1.0625" Cross-sectional area of rivet after driving. .3712 ?q. in. .4418 sq. in. .5185 sq. in. .6013 sq. in. .6903 sq. in. .8866 sq. in. Allowable Shearing Strength, in Pounds. Iron, single Bhear, Iron, double shear, Steel, single shear, Steel, double shear, 14,106 16,788 19,703 22,849 26,231 25,984 30,926 36,295 42,091 48,321 15,590 18,556 21,777 25,255 28,993 28,954 34,460 40,443 46,901 53,843 33,691 62,062 37,237 69,155 6 Part II. — Section 2. 7. The lowest factors of safety used for boilers, the shells safety." ° f or drums °f which are exposed to the products of combustion and the longitudinal joints of which are of lap-riveted con- struction, shall be as follows : — (a) Five (5) for boilers not over ten years old. (b) Five and five-tenths (5.5) for boilers over ten and not over fifteen years old. (c) Five and seventy-five hundredths (5.75) for boilers over fifteen and not over twenty years old. (d) Six (6) for boilers over twenty years old. (e) Five (5) for boilers, the longitudinal joints of which are of lap- riveted construction and the shells or drums of which are not exposed to the products of combustion. Section 2. safety valves. 1. Each boiler shall have one (1) or more safety valves. 2. The minimum size of a direct spring-loaded safety valve dXZG OI safety shall be governed by the pressure allowed, as stated in the spring- certificate of inspection, and by the grate area of the boiler, subject to the following conditions and as shown by the table in paragraph 3 of this section. Condition A. — A single boiler, or two or more boilers boners, and connected to a common steam main and allowed the same nected and pressure: the minimum size of safety valve for each boiler same pres- shall be governed by the pressure allowed, as stated in the certificate of inspection, and by the grate area of the boiler. Condition B. — When two or more boilers, which are connected allowed different pressures, are connected to a common steam different main, the minimum size of each safety valve shall be gov- erned by the pressure allowed, as stated in the certificate of inspection, and by the grate area of the boiler; and all safety valves shall be set at a pressure not exceeding the lowest pressure allowed. The aggregate valve area shall not be less than that required for the aggregate grate area, based on the lowest pressure allowed, as shown by the table. Condition C. — When two or more boilers, which are allowed different pressures, are connected to a common steam main, and all safety valves are not set at a pressure not exceeding the lowest pressure allowed, the boiler or boilers allowed the lower pressures shall each be protected by a safety valve or valves placed on the connecting pipe to the steam main; the area or combined area of the safety valve or valves placed on the connecting pipe to the steam main shall not be less than the area of the connecting pipe, except when the steam main is smaller than Part II. — Section 2. 7 the connecting pipe, when the area or combined area of safety valve or valves placed on the connecting pipe shall not be less than the area of the steam main. Each safety valve placed on the connecting pipe shall be set at a pressure not exceeding the pressure allowed on the boiler it protects. 3. A table of areas of grate surfaces, in square feet, for direct spring- loaded safety-valves, follows : — w __75_ w -ioo, w _ 160 W -160 W= 200. W=^°- 3600 3600 3600 3600 3600 3600 P= 40 P= 65 P= 115 P= 140 P= 190 P= 240 A=.401 A=.329 A=.297 A=.244 A=.224 A=.213 Maximum Pressure Zero to 25 Over 25 to Over 50 to Over 100 to Over 150 to Over 200 allowed per Square Pounds. 50 Pounds. 100 Pounds. 150 Pounds. 200 Pounds. Pounds. Inch on the Boiler. Diameter of Valve, in Inches. Area of Valve, in Square Inches. J .rea of Grate, in Square Feet. 1 .7854 2.00 2.50 2.75 3.25 3.5 3.75 m 1.2272 3.25 4.00 4.25 5.00 5.5 5.75 iy 2 1.7671 4.50 5.50 6.00 7.25 8.0 8.50 2 3.1416 8.00 9.75 10.75 13.00 14.0 15.00 Vk 4.9087 12.50 15.00 16.50 20.00 22.0 23.00 3 7.0686 17.75 21.50 24.00 29.00 31.5 33.25 3y 2 9.6211 24.00 29.50 32.50 39.50 43.0 45.25 4 12.5660 31.50 38.25 42.50 51.50 56.0 59.00 *y 2 15.9040 40.00 48.50 53.50 65.00 71.0 74.25 5 19.6350 49.00 60.00 66.00 80.00 88.0 92.25 4. When the conditions exceed those on which the table (paragraph 3) is based, the following formula shall be used: — A = ^7°X11. A = area of direct spring-loaded safety valve in square inches per square foot of grate surface. "W = weight of water in pounds evaporated per square foot of grate surface per second. P = pressure (absolute) at which the safety valve is set to blow. 5. A table of areas of grate surface, in square feet, for safety valves not direct spring-loaded, is given in paragraph 6, section 1, Part I. of these Rules. 6. If more than one (1) safety valve is used, the minimum combined area shall be in accordance with the table. 7. Each safety valve shall have full-sized direct connection Safety valve to the boiler, and when an escape pipe is used it shall be full- connections. sized and fitted with an open drain, to prevent water lodging in the upper part of safety valve or escape pipe. When a boiler is fitted with 8 Part II. — Section 2. two (2) safety valves on one (1) connection, this connection to the boiler shall have a cross-sectional area equal to or greater than the combined area of the two (2) safety valves. No valve of any description shall be placed between the safety valve and the boiler, nor on the escape pipe between the safety valve and the atmosphere. When an elbow is placed on a safety valve escape pipe it shall be located close to the safety valve outlet, or the escape pipe shall be securely anchored and supported. 8. Safety valves having either the seat or disc of cast iron shall not be used. 9. Safety valves hereafter installed on boilers shall not valves here- exceed five (5) inches in diameter, and shall be the direct installed. spring-loaded type, with seat and bearing surface of the disc inclined at an angle of about forty-five (45) degrees to the center line of the spindle ; designed with a substantial lifting device so that the disc can be lifted from its seat with the spindle, not less than one-eighth (^) the diameter of the valve, when the pressure on the boiler is seventy-five (75) per cent, of that at which the safety valve is set to blow. Fusible ^ Fusible plugs, as required by section 20, chapter 465, plugs. A c t s of 1907, shall be filled with pure tin. 11. The least diameter of fusible metal shall not be less than one-half (£) inch, except for working pressures of over one hundred and seventy- five (175) pounds, or when it is necessary to place a fusible plug in a tube, in which cases the least diameter of fusible metal shall not be less than three-eighths (f ) inch. 12. Each boiler shall have one (1) or more fusible plugs, located as follows : — (a) In Horizontal Eeturn Tubular Boilers — in the rear head, not less than two (2) inches above the upper row of tubes, measurement to be taken from the line of the upper surface of tubes to the center of the plug, as shown in Figs. 12 and 13 of these Eules, and projecting through the sheet not less than one (1) inch. (b) In Horizontal Flue Boilers — in the rear head, on a line with the highest part of the boiler exposed to the products of combustion, and projecting through the sheet not less than one (1) inch. (c) In Locomotive Type or Star Water Tube Boilers — in the highest part of the crown sheet, and projecting through the sheet not less than one (1) inch. (d) In Vertical Fire-tube Boilers — in an outside tube, not less than one-third (^-) the length of the tube above the lower tube sheet. (e) In Vertical Fire-tube Boilers, Corliss Type — in a tube, not less than one-third (^) the length of the tube above the lower tube sheet. (/) In Vertical Submerged Tube Boilers — in the upper tube sheet. Part II. — Section 2. 9 (g) In Water-tube Boilers, Horizontal Drums, Babcock & Wilcox Type — in the upper drum, not less than six (6) inches above the bot- tom of the drum, over the first pass of the products of combustion, and projecting through the sheet not less than one (1) inch. (h) In Stirling Boilers, Standard Type — in the front side of the middle drum, not less than four (4) inches above the bottom of the drum, and projecting through the sheet not less than one (1) inch. (i) In Stirling Boilers, Superheater Type — in the front drum, not less than six (6) inches above the bottom of the drum, exposed to the products of combustion, and projecting through the sheet not less than one (1) inch. (j) In Water-tube Boilers, Heine Type — in the front course of the drum, not less than six (6) inches above the bottom of the drum, and projecting through the sheet not less than one (1) inch. (k) In Robb-Mumf ord Boilers, Standard Type — in the bottom of the steam and water drum, twenty -four (24) inches from the center of the rear neck, and projecting through the sheet not less than one (1) inch. (I) In Water-tube Boilers, Almy Type — in a tube or fitting exposed to the products of combustion. (m) In Vertical Boilers, Climax or Hazelton Type — in a tube or center drum not less than one-half (J) the height of the shell, measur- ing from the lowest circumferential seam. (n) In Cahall Vertical Water-tube Boilers — in the inner sheet of the top drum, not less than six (6) inches above the upper tube sheet, and projecting through the sheet not less than one (1) inch. (o) In Scotch Marine Type Boilers — in combustion chamber top, and projecting through the sheet not less than one (1) inch. (p) In Dry Back Scotch Type Boilers — in rear head, not less than two (2) inches above the upper row of tubes, and projecting through the sheet not less than one (1) inch. (q) In Economic Type Boilers — in the rear head, above the upper row of tubes. (r) In Cast-iron Sectional Heating Boilers — in a section over and in direct contact with the products of combustion in the primary combus- tion chamber. (s) In Water-tube Boilers, Worthington Type — in the front side of the steam and water drum, not less than four (4) inches above the bot- tom of the drum, and projecting through the sheet not less than one (1) inch. (t) For other types and new designs, fusible plugs shall be placed at the lowest permissible water level, in the direct path of the products of combustion, as near the primary combustion chamber as possible. 10 Part II. — Section 2. 13. Each boiler shall have a steam gage connected to the Steam gage. ., steam space of the boiler by a syphon, or equivalent device, sufficiently large to fill the gage tube with water, and in such manner that the steam gage cannot be shut of from the boiler except by a cock with T or lever handle, which shall be placed on the pipe near the steam gage. steam ^- The ^^ °^ the steam gage shall be graduated to not gage dial. ] esg than one and one-half (1 J) times the maximum pressure allowed on the boiler. 15. Each boiler shall be provided with a one-fourth (£) testfgage? ^ ncn PiP e s ^ ze connection for attaching inspector's test gage when boiler is in service, so that the accuracy of the boiler steam gage can be ascertained, as required by section 3, chapter 465, Acts of 1907. 16. Each boiler shall have at least one (1) water glass, Water class * the lowest visible part of which shall be above the fusible plug and lowest safe water line. 17. Each boiler shall have two (2) or more gage cocks, 25 a pounds S ' located within the range of the visible length of water glass, Sss S . sure ' ° r when the maximum pressure allowed does not exceed twenty- five (25) pounds per square inch, except when such boiler has two (2) water glasses, located not less than three (3) feet apart, on the same horizontal line. 18. Each boiler shall have three (3) or more gage cocks, ov£ e 25° CkS ' located within the range of the visible length of water glass, sure? dS preS " when the maximum pressure allowed exceeds twenty-five (25) pounds per square inch, except when such boiler has two (2) water glasses, located not less than three (3) feet apart, on the same horizontal line. 19. Each boiler shall have a feed pipe fitted with a check • valve, and also a stop valve or stop cock between the check valve and the boiler, the feed water to discharge below the lowest safe water line. Means must be provided for feeding a boiler with water against the maximum pressure allowed on the boiler. 20. Each steam outlet from a boiler (except safety valve connections) shall be fitted with a stop valve. 21. When a stop valve is so located that water can accumulate, ample drains shall be provided. 22. When a damper regulator is used, the boiler pressure regulator. pip e shall be fitted with a valve or cock, and shall be con- nected to the steam space of the boiler. 23. Each boiler fitted with a Lamphrey Boiler Furnace fronts. Mouth Protector, or similar appendage, having valves on Part II. — Sections 3-4. 11 the pipes connecting the same with the boiler, shall have these valves locked or sealed open, so that the locks or seals will require to be removed or broken to shut the valves. 24. The main return pipe to a heating boiler (Gravity VjlIvgs on Return System) shall have a check valve, and also a stop return valve between the check valve and the boiler. 25. When there are two connected boilers (Gravity Return System), one (1) check valve may be placed on the main return pipe and a stop valve on the branch pipe to each boiler, as shown in Fig. 1. A. Stop Valve. B. Bottom Blow-off. a. b. Check Valve. :r=D Boiler. a. b. A. Stop Valve. B. Bottom Blow-off. X.; Boiler. Fig. 1. Section 3. 1. A boiler having one square foot of grate surface shall & ^ & . Horse be rated at three (3) horse power when the safety valve is set power to blow at over twenty-five (25) pounds pressure per square inch. 2. A boiler having two square feet of grate surface shall be rated at three (3) horse power when the safety valve is set to blow at twenty-five (25) pounds pressure per square inch, or less. Section 4. 1. The owner or user of a boiler which requires annual inspection, internally and externally, by the boiler inspec- ^JJjJIJJj tion department or by an insurance company, as provided J;?oSs C " by section 1, chapter 465, Acts of 1907, shall prepare the boiler for inspection by cooling it down (blanking off connections to adjacent boilers, if necessary), removing all soot and ashes from tubes, 12 Part II. — Sections 5-6. heads, shell, furnace and combustion chamber; drawing off the water; removing the handhole and manhole plates; removing the grate bars from internally fired boilers ; and removing the steam gage for testing. 2. If a boiler has not been properly cooled down, or otherwise pre- pared for inspection, the boiler inspector shall decline to inspect it, and he shall not issue a certificate of inspection until efficient inspection has been made. 3. In making the annual internal and external inspection, as pro- vided by sections 1 and 4, chapter 465, Acts of 1907, the boiler in- spector shall apply the hammer test to all internal and external parts of a boiler that are accessible. 4. All proper measurements shall be taken by the boiler inspector, so that the maximum working pressure allowed on a boiler will conform to the rules relating to allowable pressures established by the Board of Boiler Eules; such measurements to be taken and calculations made before a hydrostatic pressure test is applied to a boiler. 5. The steam gage of a boiler shall be tested and its readings com- pared with an accurate test gage, and if, in the judgment of the boiler inspector, the gage is not reliable, he shall order it repaired or replaced. Section 5. 1. The annual external inspection of a boiler, as provided Annual by section 3, chapter 465, Acts of 1907, should be made at spections. " or about six (6) months after the annual internal inspection, except in the case of a boiler that is in service a portion of the year only, in which case the annual external inspection shall be made during such period of service. 2. The boiler inspector shall attach an accurate test gage to a boiler, to note the pressure shown by said test gage, and compare it with that shown by the boiler gage, ordering the boiler gage repaired or replaced if necessary. 3. The boiler inspector shall see that the water glass, gage cocks, water-column connections and water blow-offs are free and clear; also, that the safety valve raises freely from its seat. 4. Fire doors, tube doors and doors in settings shall be opened, to view as far as possible the fire surface, settings, tube ends, blow-off pipes and fusible plug; the boiler inspector to note conditions and order changes or repairs if necessary. Section 6. 1. When a boiler is tested by hydrostatic pressure, the static maximum pressure applied shall not exceed one and one-half pressure x x L tests. (1 J) times the maximum allowable working pressure ; except that twice the maximum allowable working pressure may be applied on Part II. — Section 7. 13 boilers permitted to carry not over twenty-five (25) pounds pressure per square inch, or on pipe boilers. 2. When making annual inspections on boilers constructed wholly of case-iron, or on pipe boilers, a hydrostatic pressure test of not less than one and one-half (1J) times and not more than twice the maximum allowable working pressure shall be applied. 3. The boiler inspector, after applying a hydrostatic pressure test, shall thoroughly examine every accessible part of the boiler, both in- ternal and external. Section 7. 1. The efficiency that a unit of length of a riveted joint Effici has to the same unit of length of solid plate shall be calcu- of joint. lated as shown by the following examples : — T. S. = tensile strength of plate, in pounds per square inch. t = thickness of plate, in inches. b = thickness of butt strap, in inches. P = pitch of rivets, in inches, on row having greatest pitch. d = diameter of rivet after driving, in inches. a = cross-sectional area of rivet after driving, in square inches. s = strength of rivet in single shear, as given in paragraph 5, section 1, Part II. of these Rules. S = strength of rivet in double shear, as given in paragraph 5, section 1, Part II. of these Rules. c = crushing strength of mild steel, as given in paragraph 4, sec- tion 1, Part II. of these Rules. [Note. — " c " applies only to boilers constructed after Feb. 5, 1910.] n = number of rivets in single shear in a unit of length of joint. N = number of rivets in double shear in a unit of length of joint. 2. Example. single-riveted. Lap joint, longitudinal or circumferential, Lap single- riveted. fig. 2. 14 Part II. — Section 7. A = Strength of solid plate = P X t X T. S. B = Strength of plate between rivet holes = (P — d) t X T. S. C = Shearing strength of one rivet in single shear = n X s X a. D = Crushing strength of plate in front of one (1) rivet = d X t X c. Divide B, C or D (whichever is the least) by A, and the quotient will be the efficiency of a single-riveted lap joint, as shown in Fig. 2. T. S. = 55,000 pounds. t = i" = .25". P = lg" = 1.625". d = -ii" =.6875". a= .3712 square inches. s = 42,000 pounds, c = 95,000 pounds. A = 1.625 X -25 X 55,000 = 22,343. B = (1.625— .6875) .25 X 55,000 = 12,890. C = 1 X 42,000 X • 3712 = 15,590. D = .6875 X .25 X 95,000 = 16,328. 12,890 (B) = >576 Efficiency of ,- oint 22,343 (A) J J Lap double- riveted. 3. Example. — Lap joint, longitudinal or circumferential, double-riveted. Fig. 3. A = Strength of solid plate = P X t X T. S. B = Strength of plate between rivet holes =(P — d) t X T. S. C = Shearing strength of two (2) rivets in single shear = n X s X a. D = Crushing strength of plate in front of two (2) rivets = nXdXtXc. Divide B, C or D (whichever is the least) by A, and the quotient will be the efficiency of a double-riveted lap joint, 'as shown in Fig. 3. Part II. — Section 7. 15 T. S. = 55,000 pounds. t= T y = .3i25". p = 2j" = 2.875". d = f = .75*. a= .4418 square inches. s = 42,000 pounds. c = 95,000 pounds. A = 2.875 X .3125 X 55,000 = 49,414. B = (2.875 — .75) .3125 X 55,000 = 36,523. C = 2 X 42,000 X .4418 = 37,111. D = 2 X -75 X .3125 X 95,000 = 44,531. 36,523 (B) = 73g Efficiency f ■ ^ t 49,414 (A) J J 4. Example. — Butt and double strap "joint, double-riveted. Butt double- riveted. Fig. 4. A = Strength of solid plate = P X t X T. S. B = Strength of plate between rivet holes in the outer row = (P — d) t XT.S. C = Shearing strength of two (2) rivets in double shear, plus the shearing strength of one (1) rivet in single shear =NxSXa + nXsXa. D = Strength of plate between rivet holes in the second row, plus the shearing strength of one (1) rivet in single shear in the outer row = (P — 2d) t X T. S. + n X s X a. E = Strength of plate between rivet holes in the second row, plus the crushing strength of butt strap in front of one (1) rivet in the outer row = (P — 2d) t X T. S. + d X b X c. 16 Part II. — Section 7. F = Crushing strength of plate in front of two (2) rivets, plus the crush- ing strength of butt strap in front of one (1) rivet = N X d X t X c + n X d X b X c. G= Crushing strength of plate in front of two (2) rivets, plus the shearing strength of one (1) rivet in single shear = N X d X t X c + nXsXa. Divide B, C, D, E, F or G (whichever is the least) by A, and the quotient will be the efficiency of a butt and double strap joint, double- riveted, as shown in Fig. 4. T. S. = 55,000 pounds. t = §" = .375*. b = T y , = .3125 // . P = 4£" = 4.875". d = J // =.875". a= .6013 square inches. s = 42,000 pounds. S = 78,000 pounds. c= 95,000 pounds. Number of rivets in single shear in a unit of length of joint = 1. Number of rivets in double shear in a unit of length of joint = 2. A = 4.875 X .375 X 55,000 = 100,547. B = (4.875 — .875) .375 X 55,000 = 82,500. C = 2 X 78,000 X .6013 + 1 X 42,000 X .6013 = 119,057. D = (4.875 — 2 X .875) .375 X 55,000 + 1 X 42,000 X .6013 = 89,708. E = (4.875 — 2 X .875) .375 X 55,000 + .875 X .3125 X 95,000 = 90,429. F = 2X. 875X. 375X95,000 + .875 X.3125X 95,000 = 88,320. G = 2 X .875 X .375 X 95,000 + 1 X 42,000 X .6013 = 87,599. fg^p .820, Efficiency of joint. Butt triple- riveted. 5. Example. — Butt and double strap joint, triple-riveted. Fig. 5. Part II. — Section 7. 17 A = Strength of solid plate = P X t X T. S. B = Strength of plate between rivet holes in the outer row = (P — d)t XT. S. C = Shearing strength of four (4) rivets in double shear, plus the shear- ing strength of one ( 1 ) rivet in single shear = NxSXa + nXsXa. D = Strength of plate between rivet holes in the second row, plus the shearing strength of one (1) rivet in single shear in the outer row = (P— 2 d) t X T. S. + n X s X a. E = Strength of plate between rivet holes in the second row, plus the crushing strength of butt strap in front of one (1) rivet in the outer row = (P — 2 d) t X T. S. + d X b X c. F = Crushing strength of plate in front of four (4) rivets, plus the crushing strength of butt strap in front of one (1) rivet = N X d X t X c f n X d X b X c. G- = Crushing strength of plate in front of four (4) rivets, plus the shearing strength of one (1) rivet in single shear = NXdXtXc -fnxsxa. Divide B, C, D, E, F or G (whichever is the least) by A, and the quotient will be the efficiency of a butt and double strap joint, triple- riveted, as shown in Fig. 5. T. S. = 55,000 pounds. a= .5185 square inches. t = f" = .375". s = 42,000 pounds, b = 5/16" = .3125". S = 78,000 pounds. P = 6| /r = 6.5". c = 95,000 pounds. d = ||" =.8125". Number of rivets in single shear in a unit of length of joint = 1. Number of rivets in double shear in a unit of length of joint = 4. A = 6.5 X -375 X 55,000 = 134,062. B = (6.5 — .8125) .375 X 55,000 = 117,304. C = 4 X 78,000 X .5185 + 1 X 42,000 X .5185 = 183,549. D = (6.5—2 X • 8125) .375 X 55,000 + 1 X 42,000 X .5185 = 122,323. E = (6.5 — 2 X .8125) .375 X 55,000 + .8125 X .3125 X 95,000 = 124,667. F = 4 X .8125 X .375 X 95,000 + 1 X .8125 X .3125 X 95,000 = 139,902. G = 4 X -8125 X • 375X 95,000 + 1 X 42,000 X .5185 = 137,558. !o! ,8 ° 4 !^ = -875, Efficiency of joint. 134,062 (A) ' J J 18 Part II. — Section 7. Butt 6. Example. — Butt and double strap joint, quadruple- quadruple- • i j riveted. riveted. Fig. 6. A = Strength of solid plate = P X t X T. S. B = Strength of plate between rivet holes in the outer row = (P — d)t XT. S. C = Shearing strength of eight (8) rivets in double shear, plus the shearing strength of three (3) rivets in single shear = N X S X a + n X s X a. D = Strength of plate between rivet holes in the second row, plus the shearing strength of one (1) rivet in single shear in the outer row = (P— 2d) t X T. S. + n X s X a. E = Strength of plate between rivet holes in the third row, plus the shearing strength of two (2) rivets in the second row in single shear and one (1) rivet in single shear in the outer row = (P— 4d) t X T. S. + n X s X a. F = Strength of plate between rivet holes in the second row, plus the crushing strength of butt strap in front of one (1) rivet in the outer row = (P— 2d) t X T. S. + d X b X c G = Strength of plate between rivet holes in the third row, plus the crushing strength of butt strap in front of two (2) rivets in the second row and one (1) rivet in the outer row= (P — -4d)tX T. S. + n X d X b X c. H = Crushing strength of plate in front of eight (8) rivets, plus the crushing strength of butt strap in front of three (3) rivets = NXdXtXc-f-nXdXbXc. I = Crushing strength of plate in front of eight (8) rivets, plus the shearing strength of two (2) rivets in the second row and one (1) rivet in the outer row, in single shear = JSTXdXtXc + nXsXa. I Part II. — Section 8. 19 Divide B, C, D, E, F, G, H or I (whichever is the least) by A, and the quotient will be the efficiency of a butt and double strap joint quadruple-riveted, as shown in Fig. 6. T. S. = 55,000 pounds. t =!-"=. 5". b = T y'=.4375". P=15". ^ d= -if" =.9375". a= .6903 square inches. s = 42,000 pounds. S = 78,000 pounds, c = 95,000 pounds. Number of rivets in single shear in a unit of length of joint = 3. Number of rivets in double shear in a unit of length of joint = 8. A = 15 X -5 X 55,000 = 412,500. B = (15 — .9375). 5 X 55,000 = 386,718. C = 8 X 78,000 X .6903 + 3 X 42,000 X .6903 = 517,723. D = (15— 2X. 9375). 5X55, 000 + lX42,000X. 6903 = 389,930. E = (15— 4X- 9375). 5X55,000+3X42,000X- 6903 = 396, 353. F=(15 — 2X .9375) .5 X 55,000+ .9375 X .4375 X 95,000 = 399,902. G= (15— 4X .9375). 5 X 55,000+3 X .9375X .4375X95,000 = 426,269. H= 8 X .9375 X .5 X 95,000 + 3 X .9375 X .4375 X 95,000 = 473,145. I = 8 X .9375 X .5 X 95,000 + 3 X 42,000 X .6903 = 443,229. — -? i — i = .937, efficiency of joint. 412,500 (A) J J Section 8. 1. The standard size of the certificate of inspection, as authorized by section 26, chapter 465, Acts of 1907, shall of certifi- be eleven (11) inches in width and eight and one-half (8J) inches in length, and shall be made up and worded in accordance with the following copy, space having been provided for the insertion of the State Boiler Inspection Department or the name of the insurance company using the same : 20 Part II. — Section 8. JZLPW"** AMMITAI. rFnTTPirATP ANNUAL CERTinCATE OF STEAM BOILER INSPECTION At required by Chapter 485, Acta of 1907 i [Space for Company's Name ox State Boiler Inspection Department] Boiler N" Date of Imriwrinil 19 This is tO Certify that the herein-described steam boiler inspected by [Space for Company's Name or State Boiler Inspection Department! may be operated at a Pressure not to exceed pounds per square inch. Name of owner Type of boiler , . Location of boiler . Age in years : Built by , Length of shell or drum fr "»- Diameter of shell or drum in. Lowest tensile strength of shell plates lbs. per sq. in. Number and size of tubes Thickness of shell plates in. Thickness of heads in. Style of longitudinal joint in shell or drum Percentage of strength of longitudinal joint ' Location of fusible plug- [Company's Nam* Oft State Boiler Inspection Department] Signature . [Fac Sim. op Executive Oppicu's oi Cniip Inspector's Signature) altuprrtar at Suiurra. (Opfici) la accordance with Section 21, Chapter 465, Acta ol 1907. aatifr tkia %££%?* *' **" " **<' d *'* ct W *»*»w»* GT POST UNDER CLASS IN CONSPICUOUS PLACE IN ENGINE OR BOILER ROOM. tS Certifl- ^* r ^^ ie cer tificate of inspection shall be posted under glass to be'rS * n a cons pi cuous place in the engine or boiler room in which moved. foe boiler specified therein is located; and it shall not be removed therefrom except the boiler or its appendages become defect- ive, or a new certificate is issued, when it shall be removed by a mem- ber of the boiler inspection department of the district police, or an inspector holding a certificate of competency as an inspector of steam boilers, as provided by section 6, chapter 465, Acts of 1907. Pakt III. — Section 1. 21 PART III. These Rules, in addition to the Rules contained in Part II., apply to boilers installed after May 1, 1908. Section 1. Open-Hearth Boiler Plate and Rivet Steel. 1. Steel shall be made by the open-hearth process, and will be considered as manufactured by the basic method unless the report of test states that the acid method has been used. 2. All plates and rivets used in the construction of steel steel shells or drums of boilers shall be as specified by the Ameri- f^JJ and can Society for Testing Materials, adopted 1901. Process. Chemical Properties. 3. There shall be three classes of open-hearth boiler plate and rivet steel, namely, Flange or Boiler Steel, Fire-box Steel and Extra Soft Steel, which shall conform to the following limits in chemical composition : — Chemical properties. Flange or Boiler Steel (Per Cent.). Fire-Box Steel (Per Cent.). Extra Soft Steel (Per Cent.). Phosphorus shall not exceed . . J Sulphur shall not exceed Manganese, Acid, 0.06 Basic, 0.04 0.05 0.30 to 0.60 Acid, 0.04 Basic, 0.03 0.04 0.30 to 0.50 Acid, 0.04 Basic, 0.04 0.04 0.30 to 0.50 4. Steel for boiler rivets shall be of the Extra Soft class, Boiler rlvet as specified in paragraphs Nos. 3 and 5 of this section. steel - Physical Properties. 5. The three classes of open-hearth boiler plate and rivet steel — namely, Flange or Boiler Steel, Fire-box Steel and ™K£j5e S Extra Soft Steel — shall conform to the following physical qualities : — Flange or Boiler Steel. Fire-Box Steel. Extra Soft Steel. Tensile strength, pounds per square Yield point, in pounds per square inch, shall not be less than Elongation per cent, in 8 inches shall 55,000 to 65,000 y a t. s. 25 52,000 to 62,000 % T. S. 26 45,000 to 55,000 y 2 t. s. 28 22 Part III. — Section 1. Modifica- 6. For material less than five-sixteenths ( T 5 -g-) inch and eiongaSon more than three-fourths (f ) inch in thickness the following in^tbick niodifications shall be made in the requirements for elonga- material. t ion : — (a) For each increase of one-eighth (J) inch in thickness above three- fourths (f ) inch a deduction of one (1) per cent, shall be made from the specified elongation. (b) For each decrease of one-sixteenth (J-g-) inch in thickness below five-sixteenths ( T 5 g-) inch a deduction of two and one-half (2J) per cent, shall be made from the specified elongation. Bending 7. The three classes of open-hearth boiler plate and rivet tests. steel shall conform to the following bending tests ; and for this purpose the test specimen shall be one and one-half (1J) inches wide, if possible, and for all material three-fourths (f ) inch or less in thickness the test specimen shall be of the same thickness as that of the finished material from which it is cut, but for material more than three-fourths (f ) inch thick the bending test specimen may be one-half (J) inch thick. Eivet rounds shall be tested of full size as rolled. (c) Test specimens cut from the rolled material, as specified above, shall be subjected to a cold bending test and also to a quenched bend- ing test. The cold bending test shall be made on the material in the condition in which it is to be used, and prior to the quenched bending test the specimen shall be heated to a light cherry red, as seen in the dark, and quenched in water, the temperature of which is between 80° and 90° Fahrenheit. (d) Flange or boiler steel, fire-box steel and rivet steel, both before and after quenching, shall bend cold one hundred and eighty (180) degrees flat on itself without fracture on the outside of the bent por- tion. Homoge- 8. For fire-box steel a sample taken from a broken tensile neity tests. ^^ S p ec i men ghall not show any single seam or cavity more than one-fourth (J) inch long in either of the three fractures obtained on the test for homogeneity, as described in paragraph No. 13 of this section. Test Pieces and Methods of Testing. Test sped- 9. The standard test specimen of eight (8) inch gaged tensile 01 * length shall be used to determine the physical properties test * specified in paragraphs Kos. 5 and 6 of this section. The standard shape of the test specimen for sheared plates shall be as shown in Fig. 7. For other material the test specimen may be the same as for sheared plates, or it may be planed or turned parallel throughout its entire Part III. — Section 1. 23 length; and in all cases, where possible, two opposite sides of the test specimens shall be the rolled surfaces. Eivet rounds and small rolled bars shall be tested of full size as rolled. 10. One tensile test specimen will be furnished from each plate as it is rolled, and two tensile test specimens will be of tensile furnished from each melt of rivet rounds. In case any of these develops flaws or breaks outside of the middle third of its gaged length, it may be discarded and another test specimen substituted therefor. 11. For material three-fourths (f) inch or less in thickness Test the bending test specimen shall have the natural rolled surface specimens on two opposite sides. The bending test specimens cut from bending. plates shall be one and one-half (1 J) inches wide, and for material more than three-fourths ( j) inch thick the bending test specimen may be one- s' h PARA LLEL SECT! ON 3 * ~ N0T L£SS THAN @ i i 1A rs 1 — " — 3" U |8- >» Standard Test Specimen of 8" Gaged Length, Piece to be of Same Thickness as Plate. Fig. 7. half (J-) inch thick. The sheared edges of bending test specimens may be milled or planed. The bending test specimens for rivet rounds shall be of full size as rolled. The bending tests may be made by pressure or by blows. 12. One cold bending specimen and one quenched bending specimen will be furnished from each plate as it is rolled, of bending tests Two cold bending specimens and two quenched bending specimens will be furnished from each melt of rivet rounds. The homogeneity test for fire-box steel shall be made on one of the broken tensile test specimens. 13. The homogeneity test for fire-box steel is made as „ follows : A portion of the broken tensile test specimen is neit I t f sts either nicked with a chisel or grooved on a machine, trans- box steel. versely about one sixteenth ( T ^) of an inch deep, in three places about two (2) inches apart. The first groove should be made on one side two (2) inches from the square end cf the specimen ; the second, two (2) 24 Part III. — Section 1. inches from it on the opposite side; the third, two (2) inches from the last, and on the opposite side from it. The test specimen is then pnt in a vise, with the first groove abont one-f onrth (J) of an inch above the jaws, care being taken to hold it firmly. The projecting end of the test specimen is then broken off by means of a hammer, a nnmber of light blows being nsed, and the bending being away from the groove. The specimen is broken at the other two grooves in the same way. The object of this treatment is to open and render visible to the eye any seams due- to failure to weld np, or to foreign interposed matter or cavities due to gas bubbles in the ingot. After rupture, one side of each fracture is examined, a pocket lens being used, if necessary, and the length of the seams and cavities is determined. 14. For the purposes of this specification the yield point point. shall be determined by the careful observation of the drop of the beam or halt in the gage of the testing machine.' 15. In order to determine if the material conforms to the Sample for chemical chemical limitations prescribed in paragraph No. 3 of this analysis. . . ... section, analysis shall be made of drillings taken from a small test ingot. An additional check analysis may be made from a tensile specimen of each melt used on an order, other than in locomotive fire-box steel. In the case of locomotive fire-box steel a check analysis may be made from the tensile specimen from each plate as rolled. Variation in Weight. Variation 16. The variation in cross section of weight of more than in weight. %i p er cen t. from that specified will be sufficient cause for rejection, except in the case of sheared plates, which will be covered by the following permissible variations : — (e) Plates 12J pounds per square foot or heavier, up to 100 inches wide, when ordered to weight, shall not average more than 2J per cent, variation above or 2^ per cent, below the theoretical weight ; when 100 inches wide and over, 5 per cent, above or 5 per cent, below the theoretical weight. (/) Plates under 12^ pounds per square foot, when ordered to weight, shall not average a greater variation than the following : — Up to 75 inches wide, 2| per cent, below the theoretical weight ; 75 inches wide up to 100 inches wide, 5 per cent, below the theoretical weight; when 100 inches wide and over, 10 per cent, above or 3 per cent, below the theoretical weight. (g) For all plates ordered to gage there will be permitted an average excess of weight over that corresponding to the dimensions on the order equal in amount to that specified in the following table : — Part III. — Section 2. 25 Table of Allowances for Overweight for Rectangular Plates when ordered to Gage. [Plates Tvill be considered up to gage if measuring not over 1-100 inch less than the ordered gage. The weight of 1 cubic inch of rolled steel is assumed to be .2833 pound.] Plates 1-4 Inch and Over in Thickness. Width of Plate. Thickness of Plate (Inch). Up to 75 Inches 75 to 100 Inches Over 100 Inches (Per Cent.). (Per Cent.). (Per Cent.). v 4 10 14 18 Ha 8 12 16 % 7 10 13 7 Ae 6 8 10 y 2 5 7 9 %6 4V 2 6% sy 2 - 5 /8 4 6 8 Over % 3% 5 6*/ 2 Finish. 17. All finished material shall be free from injurious surface defects and laminations, and must have a workman- like finish. Finish. Plate Manufacturer to stamii Plates and Heads. 18. Each plate shall be distinctly stamped by the manu- Plates t0 be facturer with the heat number. stamped. 19. Each plate shall be distinctly stamped by the manufacturer in at least five places in the following manner : At the four corners, at a distance of about twelve (12) inches from the edges, and at or near the center of the plate, with the name of the manufacturer, place where manufactured, brand and lowest tensile strength. 20. Each head shall be distinctly stamped by the manu- Heads t0 be facturer on each side with the name of the manufacturer, stamped, place where manufactured, brand and lowest tensile strength ; stamps to be so located as to be plainly visible when the head is finished. Section 2. Material to be used. 1. Shells, drums and butt straps shall be of Open- shell Hearth Fire-box Steel, as specified in paragraphs Xos. 3 and 5, section 1, Part III. of these Rules. 2. Heads, combustion chambers, furnaces, or any plates that require staying or flanging, shall be of Open-hearth plates. Heads. 26 Part III. — Section 3. Flange, Fire-box or Extra Soft Steel, as specified in paragraphs Nos. 3 and 5, section 1, Part III. of these Eules. 3. Eivets shall be of Open-hearth Extra Soft Steel, as Rivets specified in paragraphs Nos. 3 and 5, section 1, Part III. of these Eules. 4. Cast steel for use in boiler and steam superheater mountings, manhole frames, steam pipe, fittings, side lugs, or any other parts of boilers or superheaters where cast steel is used, shall not have less than fifty thousand (50,000) pounds tensile strength. 5. Cast iron for use in boiler mountings, steam pipe fittings, side lugs, or any other parts of boilers where cast iron is permitted to be used, shall not have less than eighteen thousand (18,000) pounds tensile strength. 6. Cross pipes connecting the steam and water drums of pipes and water-tube boilers, and cross boxes, shall be of wrought or cast steel when the working pressure exceeds one hundred and sixty (160) pounds per square inch. Mud 7. Mud drums of water-tube boilers shall be of wrought drums. or cas t steel when the working pressure exceeds one hundred and sixty (160) pounds per square inch. 8. Pressure parts of superheaters, attached to boilers or heaters. separately fired, shall be of wrought or cast steel when the working pressure exceeds fifty (50) pounds per square inch. 9. Boiler and superheater mountings, such as nozzles, cross pipes, steam pipes, fittings, valves and their bonnets shall be of wrought or cast steel when exposed to steam which is superheated over 80° Fah- renheit. 10. "Waterleg and door frame rings of vertical fire-tube Le°" and door frame boilers thirty-six (36) inches or over in diameter, shall be of wrought or cast steel, or wrought iron. 11. Waterleg and door frame rings of locomotive type boilers shall be wrought or cast steel, or wrought iron. Section 3. 1. In laying out shell plates, furnace sheets and heads in be a vMWe ^ ne toiler shop, care shall be taken to leave at least one of the stamps, specified in paragraphs 19 and 20, section 1, Part III. of these Eules, so located as to be plainly visible when the boiler is completed; except that the tube sheets of a vertical fire-tube boiler shall have a portion, at least, of such stamps visible sufficient for identification when the boiler is completed. Boiler to toe ^' -^ acn b°il er shall conform in every detail with the Eules stamped. formulated by this Board, and shall be distinctly stamped Part III. — Section 3. 27 with the words MASSACHUSETTS STANDARD, abbreviated to read MASS. STD., by a member of the boiler inspection department of the district police, or an inspector holding a certificate of com- petency as an inspector of steam boilers, as provided by section 6, chapter 465, Acts of 1907, anYl who is not, directly or indirectly, interested in the manufacture or sale of steam boilers, but in the employ of an insurance company authorized to insure boilers in this Commonwealth. Each boiler shall be stamped by the builder, in the presence of the inspector, with a serial number and with the name of the builder either in full or abbreviated, and the builder shall sub- mit a fac-simile of his proposed style of stamping to this Board for approval. The height of letters and figures used in stamping shall not be less than one-fourth (J) inch. 3. In numbering serially, each builder shall commence with the number one (1) and continue numbering in con- |^J{, ers secutive order. 4. A data report, on forms to be furnished by the boiler inspection department of the district police, shall be for- Jjjjj^g warded by the builder to the chief inspector of such depart- ment for each boiler stamped MASS. STD., before the boiler is shipped from the boiler shop. 5. Location of stamps to be as follows: — Location of _ . stamps. (a) On Horizontal Eeturn Tubular Boilers — on the front head, above the central rows of tubes. (b) On Horizontal Flue Boilers — on the front head, above the flues. (c) On Locomotive Type or Star Water-tube Boilers — on the furnace end, above the handhole. (d) On Vertical Fire and Vertical Submerged Tube Boilers — on the shell, above the furnace door. (e) On Water-tube Boilers, Babcox & Wilcox, Stirling, Heine and Robb-Mumf ord Standard Types — on a head above the manhole opening, preferably on the flanging of the manhole opening. (/) On Vertical Boilers, Climax or Hazelton Type — on the top head. (g) On Cahall Vertical Water Tube Boilers — on the upper drum, above the manhole opening. (h) On Scotch Marine Boilers — on the front head, above the centre or right-hand furnace. (i) On Economic Boilers — on the rear head, above the central rows of tubes. (j) For other types and new designs — in a location to be approved by this Board. 28 Part III. — Section 4. stamps 6. The boiler builder's stamp shall not be covered by insu- covered? 6 lating or other material. 7. All boiler shops in which boilers are constructed for in- tion inspec- stallation in this Commonwealth shall be open to the mem- tion. ... bers of the boiler inspection department of the district police and inspectors holding certificates of competency as inspectors of steam boilers, as provided by section 6, chapter 465, Acts of 1907, at all reason- able hours, for inspection of material, methods of manufacture, work- manship and testing. Section 4. 1. The maximum pressure to be allowed on a steel or mine maxi- wrought-iron shell or drum of a boiler shall be determined allowable from the minimum thickness of the shell plates, the lowest tensile strength stamped on the plates by the plate manu- facturer, the efficiency of the longitudinal joint or ligament between the tube holes, whichever is the least, the inside diameter of the out- side course, and a factor of safety of not less than five (5), the formula being : — A — /wo _ max imum allowable working pressure per square inch, R XF.S. in pounds. T.S. = tensile strength of shell plates, in pounds. t = minimum thickness of shell plates, in inches. % = efficiency of longitudinal joint or ligament between tube holes, whichever is the least. E = radius = one-half (J) the inside diameter of the outside course of the shell or drum. F.S. = 5, the lowest factor of safety allowed on boilers installed after May 1, 1908. When it is desired to construct a boiler of special material, the case shall be submitted to this Board for approval. Note. — The method of determining the efficiency of longitudinal joint is given in section 7 Part II., and of determining the efficiency of ligament between tube holes in the following paragraphs. 2. Efficiency of ligament : when a shell or drum is drilled be * w 1 f e 1 n for tube holes in a line parallel to the axis of the shell or tube holes, drum, the efficiency of the ligament between the tube holes shall be determined as follows : — (a) When the pitch of tube holes on every row is equal, the formula is:— d i- = efficiency of ligament. P . . p = pitch of tube holes, in inches. d = diameter of tube holes, in inches. Part III. — Section 4. 29 Example. e- e cb cb cb /C-i X-l f'" JT'" r'" *-'" r'" e^e-e-^e-e^e-e Longitudinal Line. > Fig. 8. Pitch of tube holes in the drum of a water-tube boiler=5j"=5.25". Diameter of tube holes=3j"=3.25". p-d _^ 5. 25-3.25 p 5.25 .38, Efficiency of ligament. (Z>) When the pitch of tube holes on any one row is unequal, the formula is : — p n( j = efficiency of ligament. P = unit length of ligament, in inches. n= number of tube holes in length, P. d = diameter of tube holes, in inches. Example. (bd) cbcb (b&) cbd) 1" *3 ^-> -/ t &r.'4g,*-/g^< v/ jdeffe'^bj&pe. ^%5 S* es 7* To < A \ 7 fi"\ 7* — -*\ 44 '£-