CCLME.ORG - DIVISION 1. DEPARTMENT OF INDUSTRIAL RELATIONS CHAPTERS 1 through 6

(continued)
The term five (5) years used in this section shall mean five (5) years under steam, but in no case shall the time of service be taken as less than six (6) months per calendar year; a hydrostatic test of one and one-half (1 1/2) times the allowed pressure on the boiler shall be made in the presence of a qualified inspector at least every five (5) calendar years. Each boiler shall be subject to any additional requirements found necessary by the qualified inspector.
(b) Secondhand lap seam horizontal return tubular boilers exceeding thirty-six inches (36 ") diameter shall not be permitted a maximum allowable working pressure in excess of fifty (50) psi.
(c) The shell or drum of a boiler in which a typical lap seam crack is discovered along a longitudinal riveted seam for either butt-strap or lap-riveted construction shall be permanently discontinued for use under pressure. 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.

s 777. Boiler and Fired Pressure Vessel Inspection Fees.
See the Division of Industrial Safety's regulations contained in Chapter 3.2, Group 2, Title 8, California Administrative Code. The shop inspection fees, permit fees, and inspection fees for boilers and fired pressure vessels are reprinted in Appendix 2 of these orders.

Note: Authority cited: Section 142.3, Labor Code.

s 778. Field Inspection Fees.

s 779. Certification of Inspectors.
(a) Upon the written request of his employer, a certificate of competency may be issued to a person who is employed as provided in subsection (c) following and who obtains a passing grade in the examination prescribed by the division. The prescribed examination may be that of the National Board and shall determine the fitness and competency of any candidate for this certificate. An average of at least seventy percent (70%) shall be required for a passing grade.
(b) An applicant for a certificate of competency shall be at least three (3) years experience in boiler or unfired pressure vessel construction or repair or as an operating engineer in charge of high-pressure boilers or as inspector of steam boilers or unfired pressure vessels.
(1) bachelor of science degree in engineering from an accredited school plus one year experience in design, construction, operation or inspection of high pressure boilers and pressure vessels.
(2) An associate degree in mechanical technology plus two years experience in design, construction, operation or inspection of high pressure boiler and pressure vessels.
(3) A high school education or the equivalent plus three years experience:
(A) in high pressure boiler and high pressure vessel construction or repair, or
(B) in charge of high pressure boiler and pressure vessel operations, or
(C) in the inspection of high pressure boilers and pressure vessels.
(c) A certificate of competency may be issued only to a person employed as an inspector of steam boilers or pressure vessels by any county, city, insurance company, or by the division, or to an inspector continuously employed by a corporation or company to inspect only boilers and pressure vessels to be used by such company and not for resale. The certificate of competency shall be automatically revoked after a period of eighteen (18) months if the inspector does not make any boiler or pressure vessel inspections as evidenced by reports submitted to the division; provided, however, that this provision does not apply to supervising engineers whose regular duties include the supervision and review of the work of qualified inspectors. A written examination is required to revalidate such certificate. The employer shall notify the division when the employment of a certified inspector is terminated.
(d) Any applicant, who has previously obtained and continues to hold a commission as a boiler inspector issued by the National Board of Boiler and Pressure Vessel Inspectors, may be exempted from the written portion of the prescribed examination provided such applicant appears for an interview to determine his physical fitness and to prove his knowledge of the applicable Safety Orders of the Division. He shall have been actively engaged as a boiler inspector within eighteen (18) months prior to his application for the California certificate of competency.
(e) As near as practicable, the examination for certificate of competency shall be conducted on the first Wednesday in March, June, September, and December of each year.
(f) The Division reserves the right to decline to examine any candidate who has not had at least ninety (90) days' practical field boiler inspection experience under the supervision of a qualified inspector.
(g) Upon good cause being shown therefor, and after notice and an opportunity to be heard, the Division may revoke any certificate of competency.

Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.

s 780. Permit to Operate.
(a) Except during the time that a request for a permit remains unacted upon, no boiler subject to annual inspection by these orders shall be placed in operation until a permit to operate has been issued and posted on or near the boiler.
(b) Upon the form supplied by the division, a permit to operate shall be issued by the qualified inspector making the inspection. The permit to operate shall indicate the date of inspection, state serial number of the boiler, the pressure allowed at the time of the internal inspection, the name of the inspector, and the name of the inspection agency. No permit shall be issued until the boiler is in compliance with these Safety Orders and satisfactory notice of compliance has been transmitted to the division.
Exception: The division may issue and renew temporary permits not to exceed thirty (30) days each, to permit replacements or repairs to be made.
(c) Each permit shall be posted under glass in a conspicuous place on or near the boiler. The permit shall be available to any safety engineer employed by the division. The permit to operate shall expire when a boiler changes both ownership and location.

s 781. Attendance on Boilers.
(a) All boilers subject to these orders shall be under the direct supervision of a responsible person. Such person shall be responsible for:
(1) Safe operation of the boiler by a competent attendant.
(2) Proper maintenance of the boiler and its appurtenances.
(b) While in operation, no fired boiler subject to these orders [except those boilers exempted from annual inspection by Order 771 that are automatically controlled and oil field recovery heaters complying with subsection (d)] shall be left unattended for a period of time longer than it will take the water level to drop from the normal operating level to the lowest permissible water level in the water gage glass -or indicated by indicating devices or recorders -when the feedwater is shut off and the boilers are forced to their maximum capacity unless all of the following are complied with:
(1) The boiler is equipped with an audible alarm that will operate when the water reaches the highest and lowest permissible operating level, or, for boilers having no fixed steam or water line, when the highest permissible operating temperature is reached.
(2) The audible alarm shall be sufficiently loud that it can be plainly heard by the attendant, without the use of an auxiliary paging system, at any point in any area that the attendant is required to work. He must be close enough to the boiler room so that he can safely respond to the alarm. The response time is that period of time that it takes the water level to go from the level at which the low level alarm sounds down to the lowest permissible water level of the boiler. The high water level alarm must be set so that the attendant will have time to respond before there will be carryover from the boiler.

(3) The boiler is equipped with a low water safety device that will shut off the fuel to the burner or burners when the water reaches the lowest permissible operating level, or, for boilers having no fixed steam or water line, when the highest permissible operating temperature is reached. This device shall require manual resetting unless the pilot is equipped with a full safety pilot control.
(4) The attendant shall personally check the operation of the boiler, the necessary auxiliaries and the water level in the boiler at such intervals as are necessary to insure the safe operation of the boiler; provided, however, that the maximum interval the boiler and its auxiliaries can be left without checking shall not exceed 60 minutes. The operation of the automatic controls shall be checked at the beginning of each shift. It is the intent of this Section to prohibit the use of time clocks to control the operation of fired boilers covered under this subsection 781(b).
(5) All float chambers of automatic controls shall be dismantled for inspection at the annual boiler inspection.
(c) The competent attendant shall be a person who is familiar with the boiler and who has been properly instructed in its safe operation.
The recommended minimum standards to be used by the employer to determine the competency of an attendant are:
(1) He shall be able to explain the function and operation of all controls on the boiler or boilers.
(2) He shall be able to light off the boiler or boilers in a safe manner.
(3) He shall know all possible methods of feeding water to the boiler or boilers.
(4) He shall know how to blow down the boiler or boilers in a safe manner.
(5) He shall know what would happen if the water was permitted to drop below the lowest permissible operating level.
(6) He shall know what would happen if the water in the boiler was carried too high.
(7) He shall know how to shut down the boiler or boilers.
(d) An oil field recovery heater designed for automatic operation shall be checked by a competent attendant at least once every 24 hours while in operation to determine that the heater is operating safely within the set operating conditions and provided that each of the following are complied with:
(1) The heater is equipped with automatic safety shutdown devices for each of the following conditions:
(A) Excessive tube skin or steam temperature
(B) Excessive steam pressure
(C) Flame failure
(D) Inadequate combustion air
(2) Within intervals not to exceed every 60 days of operation of the heater, the following inspection checks shall be performed by a person familiar with the equipment and who has been properly instructed in making such checks:

(A) Each safety shutdown device shall be tested for proper operation.
(B) All external piping and wiring shall be visually checked for obvious defects.
(C) All indicating gages shall be checked for proper calibration.
Equipment defects found in (A), (B), or (C) above shall be corrected before continuing the boiler in service.
(3) At the time of the annual inspection of the heater and its accessory equipment, all automatic operating controls and automatic safety shutdown devices which are not failsafe shall be serviced as necessary to assure their continued reliability to include:
(A) Replace vacuum tubes and check sensing devices in the flame-failure system and replace if not operating properly.
(B) Test all coils, diaphragms, and other operating parts of all safety shutdown and operating control valves. Such servicing shall be done by a person familiar with such controls and devices and who has been properly instructed in their servicing.
(4) A record shall be kept of the inspection and maintenance operations required by (2) and (3) above and this record shall be available to the certified inspector at the time of the annual inspection.

Note: Authority cited: Sections 6312, 6500 and 6502, Labor Code.

s 782. Safe Practices.
(a) The following Safety Orders from Title 8, California Administrative Code are hereby made a part of these orders:
(1) General Industry Safety Order 3228(i): Number of Exits, Boilers Furnace and Incinerator Rooms. See Appendix 1.
(2) General Industry Safety Order 3274: Valves and Controls. See Appendix 1.

(3) General Industry Safety Order 3311: Flarebacks. See Appendix 1.
(4) General Industry Safety Order 3312: Entering Combustion Chambers, Flues, Boilers or Unfired Steam Pressure Vessels. See Appendix 1.
(5) General Industry Safety Order 3310: discharge Location. See Appendix 1.
(6) General Industry Safety Order 3514: Tubular Gage Guard. See Appendix 1.
(7) General Industry Safety order 3515: Try Cock Discharge Resceptable. See Appendix 1.
(8) General Industry Safety Order 3516: Steam Gage and Water Gage Glass Location. See Appendix 1.
(b) All fired boilers, not included in Sections 763 and 771, equipped with controls to permit the burners to be ignited automatically shall be equipped with a full safety pilot or other device that will provide equivalent safety. Such safety pilot or other device shall be of a type that will de -energize the electrical circuit and/or cause the main burner fuel valve to close within the following burner input and time limits.

400,000 BTU/HR and under.......... 90 seconds
400,001 to 2,500,000 BTU/HR....... 9 seconds
Over 2,500,000 BTU/HR............. 5 seconds

(c) All dampers used in smokestacks of boilers which use natural draft shall have suitable openings to vent the furnace.
(d) When portable electric lights are used inside any boiler or pressure vessel they shall be equipped with a vaportight globe, substantial guard, rugged nonconducting lamp holder and handle, and shall have type S cord or equivalent sufficiently long to reach to a plug-in or junction box outside the vessel.

s 783. Renewals and Replacements.
All renewals or replacement boiler drums, shells, headers, tubes or appurtenances shall comply with the requirements of the code for new construction.

s 784. Approval and Reporting of Repair.
(a) No repairs to drums, shells, stayed or unstayed surface of a boiler shall be made until the contemplated repairs have been approved by a qualified inspector. (This order shall not prohibit the replacement of tubes, staybolts and/or appurtenances without inspection where replacement is necessitated by normal usage and wear.)
(b) No repairs shall be made to any boiler which has moved from its setting or foundation due to the failure of the boiler or any part thereof until approved by the division.
(c) All repairs by fusion welding or riveting to a damaged boiler or boiler support, where the safety of the boiler is concerned, shall immediately be reported to the division by the qualified inspector who authorized the repair. Complete details with sketches of all repairs, including the identification number of the welder, if welding is used, shall be submitted to the division by the qualified inspector.

s 785. Permissible Welded Patches and Welded Repair of Cracked Plates in Material of Known Weldable Quality.
The following welded repairs are permissible:
(a) Cracks in unstayed shells, drums, or headers of boilers or fired pressure vessels may be repaired by welding provided:
(1) The cracks do not extend between rivet holes in a riveted longitudinal seam.

(2) The crack is not located within six inches (6 ") of the calking edge of any longitudinal riveted seam.
(3) The total length of any one crack shall not exceed sixteen (16) times the plate thickness or eight inches (8 ") unless the completed repair is radiographed and stress-relieved.
(b) Cracks or patches in stayed surfaces may be welded provided:
(1) The crack or patch seam is located between two (2) rows of staybolts.
(2) The crack or patch seam if located in a flange or knuckle runs in a direction transverse to the flange or knuckle.
(3) The patch is set flush with adjacent plate and the welds are located between two (2) rows of staybolts.
(c) Cracks between tube holes in water-tube boiler drums or heads may be welded, provided there are not more than two (2) such cracks in any one row in any direction, nor more than a total of four (4) such cracks in any one drum or header and providing the diameter of the drum is not more than one percent (1%) out of round.
(d) Fire cracks extending from rivet hole to rivet hole in girth seams may be welded, provided there are not more than three (3) consecutive cracked ligaments nor more than a total of six (6) cracked ligaments in any one girth seam.
(e) Cracks between tube holes in fire-tube boilers not exceeding three (3) consecutive cracked ligaments may be welded.
(f) Cracks not to exceed two inches (2 ") in length in wrought or cast steel (not cast iron) sectional headers of water-tube boilers may be welded except that not more than four (4) such cracks in any one header may be welded.
(g) Circumferential cracks in the knuckle or turn of a flange of a furnace or flue opening or adjacent to manhole opening of unstayed heads shall not be repaired by welding. When such cracks occur in an ogee flange, the affected material including the flange shall be removed and replaced by a flush patch of similar shape. The abutting edges shall be welded and the flange shall be riveted to the shell. Scotch marine and similar boilers shall have one (1) flange riveted to the shell or furnace and the other flange shall be attached by rivets or patch bolts.
(h) All welded patches installed in unstayed drums, shells or heads and exceeding the size of an unreinforced opening in paragraph PG-32 of the Code shall be flush-welded patches and shall be radiographed and post weld heat treated. The corner radius of such patches shall be rounded to a radius of at least twice the plate thickness. A joint efficiency of 90 percent (or more if allowed by the Code to which the boiler was built) shall be used in calculating the maximum allowable working pressure of such patches.
(i) Lap welded patches may be used to close openings in unstayed shells, drums, or heads providing:
(1) The maximum dimension of the opening does not exceed the size of an unreinforced opening in paragraph PG-32 of the Code.
(2) Two or more of such openings are not so located that they form a ligament in the longitudinal direction of the shell or drum.
(3) The patch plate is installed on the pressure side of the plate and has a lap of at least one inch (1 ").

(4) The patch plate is not exposed to the products of combustion.
(j) Any portion of the tube sheet of a horizontal tubular boiler may be repaired by a flush welded patch providing:
(1) No welded repair shall be permitted in the knuckle in a circumferential direction.
(2) The patch shall be held in place by stays, tubes, or both.
(3) Where the patch extends to the outer row of tubes, it shall include the flanged portion of the head and be secured to the shell in the same manner as the original construction.
(k) The top tube sheet of a vertical tubular boiler may be replaced by a flush welded patch, provided the welded seam is not located nearer than one inch (1 ") to the knuckle or curved part of the original head. The bottom tube sheet of a vertical tubular boiler shall not be so repaired.
( l) Pipe connections up to three-inch (3 ") pipe size may be installed by welding without stress-relieving, provided the coupling used has a flange on the pressure side of the sheet and the welding is for tightness only. This type of repair shall not be used for blowoff connections or openings exposed to the products of combustion.
(m) Post weld heat treatment of a repaired part by heating, when necessary, shall be done in accordance with paragraph PW-39 of the Code. Care should be exercised in applying heat in the vicinity of riveted joints to avoid loosening of rivets. Peening may be used in lieu of post weld heat treatment at the discretion of the Division.
(n) Radiography of welded repairs, when required, shall be done in accordance with paragraph PW-51 of the Code.
(o) The thickness of any patch shall be equal to but not more than one-eighth inch (1/8 ") thicker than the plate being patched.
(p) All flush welded patches in unstayed surfaces shall be butt-doubled-welded or equivalent. Patch material shall conform to the requirements of Order 794(g) and (h).

s 786. Preparation for Welding.
(a) All cracks permitted to be repaired by welding shall be chipped or ground to form a clean welding groove with an included angle of not less than sixty degrees (60) and extending to a depth equal to at least the plate thickness less one-sixteenth inch (1/16 "). The welding groove shall be extended until the crack has been removed for its entire length. Whenever possible the root of the weld shall be chipped out to clean metal and welded.
(b) Prior to repairing cracks by welding, all tubes, rivets, and threaded staybolts within 6 inches of the crack shall be removed. After welding is completed, such tube, rivet and/or staybolt holes shall be reamed before installing new tubes, rivets, or staybolts. For threaded staybolts the holes shall be tapped and new threaded staybolts installed. If a crack originates or terminates at a welded staybolt, the staybolt shall be removed prior to repairing the crack. After welding is completed, the hole shall be properly prepared for installation of the new staybolt in accordance with paragraph PW-19 of the Code.

s 788. Repair of Corroded Surfaces.
The following corroded surfaces may be built up by fusion welding:
(a) Corroded surfaces in stayed sheets including tube sheets of fire-tube boilers, provided the remaining thickness is at least fifty percent (50%) of the original thickness and further provided the affected areas are not sufficiently extensive to seriously impair the safety of the object; the qualified inspector shall decide when such areas shall be repaired by other means.
(b) Corroded surfaces in plate around handholes or manholes in unstayed sheets within three inches (6 ") of the opening, provided the remaining thickness is not less than fifty percent (50%) of the original thickness.
(c) Calking edges of girth seams, provided the metal remaining between the rivet and calking edge to be built up is at least fifty percent (50%) of the original thickness and also provided the length of calking edge to be built up does not exceed a length equal to the diameter of the boiler. Before any welding is done, all rivets in the affected area and six inches (6 ") beyond each portion to be built up shall be removed. After the welded repair has been completed the rivet holes shall be reamed and new rivets driven.
(d) The building up or repair by welding of rivet heads, staybolts, braces, or attachments to braces, or grooved areas is not permitted.
(e) Scattered pits and corrosion in unstayed shells may be built up by welding, provided the largest dimension of such corroded area does not exceed the diameter of an unreinforced opening in paragraph PG-32 of the Code and providing such areas are not so located that they form a ligament in the longitudinal direction.

s 789. Permissible Repair by Seal Welding.
(a) The ends of all tubes, suspension tubes, and nipples of water-tube boilers and superheaters may be seal-welded in accordance with the provisions of paragraph PWT-11 of the Code.
(b) Seal-welding of circumferential joints is permissible, provided the seam is calked first and made tight under hydrostatic pressure equal to the working pressure.
(c) The ends of fire tubes may be seal-welded provided the thickness of the tube is at least seventy-five percent (75%) of its original thickness, and the tubes are first rolled and beaded and found tight under hydrostatic pressure at least equal to the working pressure. The throat of the weld shall not exceed three-sixteenths inch (3/16 ").

s 790. Permissible Tube Repair.
(a) All the tubes in a firetube boiler may be retipped, provided the tube wall thickness of the original tube is not less than ninety percent (90%) of the original thickness and the retipped ends are from new material. The new end shall be located in the tube sheet subject to the greatest heat. The circumferential welds in such tubes shall not exceed four (4) in number.
(b) Complete replacement of sections of tubes or pipe in water-tube boilers is permitted, providing the remaining tube is not less than the thickness required for the designed working pressure and the requirements of paragraph PW-41 of the Code are complied with.
(c) Bulges in tubes of water-tube boilers may be repaired when:
(1) The maximum dimension of the repaired area does not exceed the diameter of the tube or two inches (2 ") whichever is the least.
(2) There are not more than three (3) such repairs in any one (1) tube.
(3) The tube wall adjacent to the bulge is not less than the thickness required for the designed working pressure.
(4) The requirements of paragraph PW-41 of the Code are complied with.

s 793. Qualification of Welding Procedures and Operators.
No welded repair shall be made to any boiler or boiler appurtenance until the welding procedure and operator have been qualified in accordance with Section IX of the code in the overhead and horizontal positions. The certificate of competency number of the qualified inspector authorizing the repair shall be stamped adjacent to all welded repairs made to power boilers.
On welded repairs that are completely radiographed the operator qualification may be eliminated at the discretion of the division provided the welding procedure is properly qualified inspector indicates on his report the welding procedure used and the operator employed in making the repair.

s 794. Riveted Patches.
(a) Riveted patch seams exposed to the products of combustion may be double-riveted or constructed similar to the original seams of the boiler.
(b) Patches exceeding twenty-four inches (24 ") in length shall have the proper width as determined by these orders. Patches exceeding fifteen inches (15 ") to and including twenty-four inches (24 ") in length shall be triangular, crescent, diamond, or oval in shape and width, W, in the circumferential direction, shall be at least twice the length, L, in the longitudinal direction. Patches fifteen inches (15 ") or less in longitudinal direction may be circular in shape.
(c) If it is found that a patch will extend extremely high, and also to avoid calking in sharp corners, it may be shortened in width to the extent that not more than four (4) rivets will be in a longitudinal line, as shown in Figure 2.
(d) If it is found that a patch will have to be sixty inches (60 ") or more in length, consideration should be given to the use of a sheet having a width equivalent to five-eighths (5/8) of the circumference of the boiler, and the longitudinal seam shall be of a design similar to the design of the original seam of the boiler.
(e) In laying out new patches over twenty-four inches (24 ") long, it is recommended that they be triangular or diamond in shape as may be required for the particular job; with definite straight-line sides but with corners properly rounded to permit adequate caulking, as illustrated in Figures 1, 2, 3, and 4. The length designated as "L" and the width designated as "W" are also shown in Figures 1, 2, 3, and 4.
(f) Rivets shall be used in "riveted" patch seams unless their use is difficult or impossible, in which case, patch bolts may be used. Rivet holes may be countersunk in patches on shells that have the heads supported by tubes or braces, providing the angle of the chamfer with the center line of the rivet hole does not exceed forty-five degrees (45 degrees), and the depth does not exceed half the thickness of the plate.
(g) Patch material shall be of fire box or flange steel depending upon the plate it replaces. Tank steel shall not be used. The repair shop shall be required to produce a copy of the manufacturer's mill test report for the material to be used.
(h) The patch plate material shall contain the steelmaker's brand. If only a part of a plate is required and this part does not contain the brand, the brand shall be transferred to the patch plate in the presence of a qualified inspector or a representative of the plate manufacturer before the plate is cut. Replacement rivets, patch bolts, and staybolts shall be of material approved for new construction by the code.
(i) All patch plates except patch plates containing blowoff connections shall be placed inside of the boiler shell or drum if exposed to the products of combustion and if installed where there is a possibility that scale deposits may be pocketed. Patch plates containing blowoff connections shall be placed on the outside of the boiler shell.

s 795. Installation of Riveted Patches.
(a) The following procedure shall be followed when installing riveted patches:
(1) Distorted sheets which require patching shall first be set back straight as nearly as possible before proceeding with the cutting out of the plate so that the patch may be kept as small as possible.
(2) All defective or deteriorated material shall be removed and properly trimmed to provide for caulking and neat workmanship in attaching the patch.

(3) The edges of a patch shall be beveled for calking by planing, chipping, or gas cutting before applying it to the boiler. Rivets should be driven by gun, if at all possible.
(4) All rivet holes shall be drilled full size or the holes may be punched not to exceed one-fourth inch (1/4 ") less than full size for plates over five-sixteenths inch (5/16 "), and one-eighth inch (1/8 ") less than full size for plates five-sixteenths inch (5/16 ") or less in thickness, and then reamed to full size with patch in place. Rivet holes shall be not more than one-sixteenth inch (1/16 ") greater in diameter than the nominal diameter of the rivet.
(5) Seal welding of the patch plate is permissible if a single bead is used with a throat thickness not more than three-sixteenths inch (3/16 "). The patch shall be tight under a hydrostatic test pressure equal to the operating pressure before seal welding. Rivets and patch bolts shall not be seal welded.
(6) When three (3) plates are lapped at the corners of a patch, the middle plate shall be scarfed carefully to a feather edge the entire width of the lap as shown in Figure 1.

(7) Upon the completion of repairs, a hydrostatic test of one hundred fifty percent (150%) of the maximum allowable operating pressure shall be applied. All seams shall be tight at this pressure.

s 796. Riveted Patch Seam Calculations.
(a) Riveted patch seams are calculated as follows:
(1) Determine the length, L, of the patch from the area of the defect to be repaired (Figures 1, 2, 3, and 4). The normal efficiency, e, of the single-riveted seam that is to be used in the patch should then be determined from Table 1. This is governed by the thickness of plate and diameter of rivet holes.
Table 1 EFFICIENCIES OF SINGLE -RIVETED SEAMS

Plate ............ Rivet Hole ......... Pitch of ........... Efficiency of
Thickness, t ..... Diameter, d ........ Rivet, p ........... Seam, e
1/4 .............. 11/16 .............. 1 7/8 .............. 63.6
9/32 ............. 3/4 ................ 1 7/8 .............. 60.3
5/16 ............. 3/4 ................ 1 7/8 .............. 60.0
11/32 ............ 13/16 .............. 1 15/16 ............ 58.0
3/8 .............. 13/16 .............. 1 15/16 ............ 57.0
13/32 ............ 7/8 ................ 2 1/16 ............. 57.5
7/16 ............. 15/16 .............. 2 1/4 .............. 56.0
15/32 ............ 15/16 .............. 2 1/8 .............. 55.5
1/2 .............. 1 .................. 2 1/4 .............. 55.7
9/16 ............. 1 1/16 ............. 2 3/8 .............. 53.0
19/32 ............ 1 1/16 ............. 2 1/4 .............. 52.8
5/8 .............. 1 1/16 ............. 2 1/4 .............. 50.5
21/32 ............ 1 1/8 .............. 2 5/16 ............. 51.4
11/16 ............ 1 1/8 .............. 2 5/16 ............. 51.4
Tensile strength assumed at 55,000 psi and shearing strength at 44,000 psi.

After determining the length, L, of a patch, determine its width girthwise, W. This is found by multiplying the length by the constant, C, as shown in Table 2 or 3, depending upon the type of boiler to be repaired. These tables give a constant, C, for a given efficiency, e, of patch and efficiency, E, of the longitudinal seam.
(2) To determine the longitudinal efficiency of an existing patch, the length, L, and width, W, the pitch, P, and the diameter, d, of rivet, should be measured. "W" divided by "L" will give the constant, C. Table 1 will give "e." Then under "e" in Table 2 or 3, depending upon the type of boiler to be repaired, find the constant, C. Whatever "E" is in the first column is the longitudinal or allowed efficiency of the patch seam.

s 797. Example of the Application and Explanation of Patch Tables and Charts.
(a) A patch is to be placed in the fire sheet of a horizontal return tubular boiler having a shell plate seven-sixteenths-inch (7/16 ") thick, a longitudinal seam efficiency of seventy-four percent (74%), and a length of patch of thirty-six inches (36 "). Find the width, W, of patch to be applied so that there will be no reduction in pressure, using a single-riveted seam of normal design.
Referring to Table 1, it is found that seven-sixteenths-inch (7/16 ") plate with fifteen-sixteenths-inch (15/16 ") diameter rivet holes, pitched two and one-fourth (2 1/4) gives a seam efficiency of fifty-six percent (56%).
Referring to Table 2, E = 0.74 and e = 0.56 gives a constant C = 1.75; then width W = L x C = 36 x 1.75 = sixty-three inches (63 ").
(b) Pressure Allowed on an Existing Patch.
A crescent-shaped patch has already been installed on a horizontal-tubular boiler. It is thirty inches (30 ") long and forty-eight inches (48 ") wide. The seam is single riveted with thirteen-sixteenths-inch (13/16 ") rivet holes pitched one and fifteen-sixteenths inches (1 15/16 "). The boiler shell plate is three-eighths-inch (3/8 ") thick. The longitudinal seam is of the double-riveted butt-strap type having an efficiency of eighty-two percent (82%). The safety valve is set for one hundred twenty-five pounds (125#) pressure. What maximum pressure should be allowed on the boiler? Reference to Table 1, shows that the normal efficiency of the patch seam is fifty-seven percent (57%). (If the efficiency is not found in the Table, refer to any other available table or determine it in the manner described in paragraphs A-1, A-2 and A-3 of the Appendix of the A.S.M.E. Boiler Code.)

Divide the width of the patch, W = forty-eight inches (48 ") by the length, L = thirty inches (30 ") to find the constant, C = 48/30 = 1.60. Follow down column 0.57 of Table 2 until 1.60 is found. It will be noted that this is somewhere between 1.56 and 1.62 representing E somewhere between 0.72 and 0.73. As the difference between 1.56 and 1.62 is 6, and the difference between 1.56 and 1.60 is 4, E will be 0.72 plus 4/6 of 0.01 which is 0.7266.
The maximum allowable working pressure varies directly as the seam efficiency. Accordingly, P = (0.7266/0.82) x 125 = 110#. If this pressure allowance interferes with the operation of the plant, the patch shall be replaced by a new one with the proper dimensions giving a diagonal efficiency of eighty-two percent (82%).
(c) Design of Patch for Water-tube Boiler.
Reference to Table 1 shows that a single-riveted lap seam with seven-sixteenths-inch (7/16 ") plate, fifteen-sixteenths-inch (15/16 ") diameter rivet holes, and two-and-one-half-inch (2 1/2 ") pitch has a normal efficiency of fifty-six percent (56%).
Reference to Table 3, shows E = 0.82 and e = 0.56, the constant C is 3.16.
Then width W = C x 1 / 2.
W = 3.16 x 36 / 2 = 56.88 or practically fifty-seven inches (57 ").

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CONSTANT 'C' TRIANGLE OR CRESCENT SHAPE PATCHES
TABLE F-1 HEADS SUPPORTED DIAMOND OR OVAL SHAPEPATCHES
'6' EFFICIENCY OF PATCH SEAMS
.50 .. .51 .. .52 .. .53 .. .54 .. .55 .. .56 .. .57 .. .58 .. .59 ..
.65 . 1.68 . 1.60 . 1.51 . 1.43 . 1.26 . 1.36 . 1.20 . 1.13 . ____ . ____ .
.66 . 1.75 . 1.67 . 1.58 . 1.50 . 1.42 . 1.35 . 1.27 . 1.19 . ____ . ____ .

.67 . 1.82 . 1.73 . 1.65 . 1.57 . 1.49 . 1.41 . 1.33 . 1.26 . 1.18 . ____ .
.68 . 1.88 . 1.79 . 1.70 . 1.63 . 1.55 . 1.47 . 1.40 . 1.32 . 1.24 . 1.16 .
.69 . 1.94 . 1.86 . 1.77 . 1.69 . 1.61 . 1.53 . 1.43 . 1.38 . 1.30 . 1.23 .
.70 . 2.01 . 1.91 . 1.83 . 1.75 . 1.67 . 1.59 . 1.52 . 1.44 . 1.36 . 1.30 .
.71 . 2.06 . 1.97 . 1.89 . 1.81 . 1.73 . 1.65 . 1.57 . 1.50 . 1.43 . 1.35 .
.72 . 2.12 . 2.03 . 1.95 . 1.86 . 1.79 . 1.71 . 1.63 . 1.56 . 1.48 . 1.41 .
.73 . 2.17 . 2.09 . 2.00 . 1.93 . 1.85 . 1.77 . 1.69 . 1.62 . 1.54 . 1.47 .
.74 . 2.22 . 2.14 . 2.06 . 1.98 . 1.91 . 1.83 . 1.75 . 1.67 . 1.60 . 1.52 .
.75 . 2.28 . 2.20 . 2.12 . 2.04 . 1.96 . 1.89 . 1.81 . 1.73 . 1.66 . 1.58 .
.76 . 2.34 . 2.25 . 2.17 . 2.09 . 2.02 . 1.93 . 1.86 . 1.79 . 1.71 . 1.64 .
.77 . 2.39 . 2.31 . 2.22 . 2.15 . 2.07 . 2.00 . 1.92 . 1.84 . 1.76 . 1.69 .
.78 . 2.44 . 2.36 . 2.28 . 2.20 . 2.13 . 2.05 . 1.97 . 1.89 . 1.82 . 1.75 .
.79 . 2.50 . 2.42 . 2.33 . 2.25 . 2.18 . 2.10 . 2.03 . 1.95 . 1.87 . 1.81 .
.80 . 2.55 . 2.46 . 2.39 . 2.30 . 2.23 . 2.15 . 2.06 . 2.00 . 1.93 . 1.86 .
.81 . 2.60 . 2.51 . 2.43 . 2.36 . 2.28 . 2.20 . 2.13 . 2.05 . 1.98 . 1.91 .
.82 . 2.65 . 2.56 . 2.48 . 2.40 . 2.33 . 2.25 . 2.18 . 2.11 . 2.03 . 1.97 .
.83 . 2.70 . 2.62 . 2.53 . 2.45 . 2.38 . 2.30 . 2.22 . 2.15 . 2.08 . 2.01 .
.84 . 2.75 . 2.66 . 2.59 . 2.51 . 2.43 . 2.35 . 2.27 . 2.20 . 2.13 . 2.06 .
.85 . 2.80 . 2.71 . 2.63 . 2.56 . 2.48 . 2.40 . 2.32 . 2.25 . 2.18 . 2.11 .
.86 . 2.85 . 2.77 . 2.68 . 2.60 . 2.52 . 2.45 . 2.37 . 2.30 . 2.23 . 2.16 .
.87 . 2.90 . 2.82 . 2.74 . 2.65 . 2.57 . 2.49 . 2.42 . 2.34 . 2.28 . 2.21 .

.88 . 2.96 . 2.87 . 2.78 . 2.71 . 2.62 . 2.54 . 2.47 . 2.40 . 2.32 . 2.25 .
.89 . 3.01 . 2.92 . 2.83 . 2.75 . 2.68 . 2.59 . 2.52 . 2.44 . 2.37 . 2.30 .
.90 . ____ . 2.97 . 2.89 . 2.80 . 2.71 . 2.65 . 2.57 . 2.50 . 2.42 . 2.34 .
.91 . ____ . ____ . 2.94 . 2.86 . 2.77 . 2.69 . 2.62 . 2.54 . 2.47 . 2.39 .
.92 . ____ . ____ . 2.99 . 2.90 . 2.82 . 2.74 . 2.66 . 2.59 . 2.51 . 2.44 .
.93 . ____ . ____ . ____ . 2.95 . 2.87 . 2.78 . 2.70 . 2.63 . 2.56 . 2.48 .
.94 . ____ . ____ . ____ . ____ . 2.91 . 2.83 . 2.75 . 2.67 . 2.60 . 2.53 .
.95 . ____ . ____ . ____ . ____ . ____ . 2.87 . 2.79 . 2.72 . 2.64 . 2.57 .
.65 . 2.20 . 2.06 . 1.93 . 1.80 . 1.69 . 1.56 . 1.45 . 1.35 . 1.24 . 1.14 .
.66 . 2.30 . 2.16 . 2.03 . 1.90 . 1.78 . 1.66 . 1.55 . 1.45 . 1.34 . 1.22 .
.67 . 2.40 . 2.26 . 2.13 . 2.00 . 1.86 . 1.75 . 1.64 . 1.52 . 1.43 . 1.32 .
.68 . 2.50 . 2.36 . 2.23 . 2.10 . 1.98 . 1.86 . 1.73 . 1.63 . 1.52 . 1.42 .
.69 . 2.62 . 2.46 . 2.33 . 2.20 . 2.07 . 1.95 . 1.84 . 1.71 . 1.61 . 1.50 .
.70 . 2.75 . 2.57 . 2.43 . 2.30 . 2.16 . 2.04 . 1.93 . 1.80 . 1.69 . 1.59 .
.71 . 2.87 . 2.70 . 2.53 . 2.40 . 2.26 . 2.14 . 2.02 . 1.90 . 1.79 . 1.67 .
.72 . 3.00 . 2.81 . 2.65 . 2.48 . 2.36 . 2.23 . 2.11 . 1.99 . 1.88 . 1.76 .
.73 . 3.14 . 2.93 . 2.76 . 2.60 . 2.46 . 2.33 . 2.20 . 2.09 . 1.97 . 1.87 .
.74 . 3.28 . 3.07 . 2.87 . 2.71 . 2.56 . 2.42 . 2.30 . 2.19 . 2.06 . 1.93 .
.75 . 3.38 . 3.19 . 3.00 . 2.83 . 2.66 . 2.52 . 2.40 . 2.27 . 2.15 . 2.05 .
.76 . 3.52 . 3.32 . 3.14 . 2.96 . 2.78 . 2.62 . 2.49 . 2.36 . 2.24 . 2.12 .
.77 . ____ . 3.46 . 3.28 . 3.07 . 2.90 . 2.74 . 2.58 . 2.45 . 2.32 . 2.22 .

.78 . ____ . ____ . 3.40 . 3.19 . 3.03 . 2.85 . 2.69 . 2.55 . 2.42 . 2.30 .
.79 . ____ . ____ . ____ . 3.32 . 3.16 . 2.97 . 2.80 . 2.65 . 2.51 . 2.39 .
.80 . ____ . ____ . ____ . 3.46 . 3.28 . 3.10 . 2.92 . 2.75 . 2.61 . 2.48 .
.81 . ____ . ____ . ____ . ____ . 3.40 . 3.20 . 3.03 . 2.87 . 2.71 . 2.57 .
.82 . ____ . ____ . ____ . ____ . ____ . 3.34 . 3.16 . 2.97 . 2.82 . 2.67 .
.83 . ____ . ____ . ____ . ____ . ____ . 3.46 . 3.29 . 3.10 . 2.83 . 2.78 .
.84 . ____ . ____ . ____ . ____ . ____ . ____ . 3.39 . 3.22 . 3.05 . 2.87 .
.85 . ____ . ____ . ____ . ____ . ____ . ____ . ____ . 3.32 . 3.17 . 2.99 .
.86 . ____ . ____ . ____ . ____ . ____ . ____ . ____ . 3.45 . 3.29 . 3.13 .
.87 . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . 3.40 . 3.24 .
.88 . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . 3.32 .
.89 . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . 3.46 .
.90 . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ .
.91 . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ .
.92 . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ .
.93 . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ .
.93 . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ .
.93 . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ .
.94 . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ .
.95 . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ . ____ .
1...+...10....+...20....+...30....+...40....+...50....+...60....+...70....+.

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******* This is piece 2. -- It begins at character 77 of table line 1. ********
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C=W+L W=CxL L=W+C
C=2W+L W+CxL+2 L=2W+C
.60 .. .61 .. .62 .. .63 .. .64 .. .65
____ . ____ . ____ . ____ . ____ . ____
____ . ____ . ____ . ____ . ____ . ____
____ . ____ . ____ . ____ . ____ . ____
____ . ____ . ____ . ____ . ____ . ____
1.15 ........ ____ . ____ . ____ . ____
1.22 . 1.15 . ____ . ____ . ____ . ____
1.28 . 1.21 . 1.15 . ____ . ____ . ____
1.34 . 1.27 . 1.20 . 1.14 . ____ . ____
1.40 . 1.33 . 1.26 . 1.19 . 1.13 . ____
1.45 . 1.39 . 1.32 . 1.25 . 1.18 . ____
1.51 . 1.44 . 1.37 . 1.31 . 1.24 . 1.17
1.57 . 1.50 . 1.43 . 1.36 . 1.30 . 1.23

1.62 . 1.55 . 1.48 . 1.42 . 1.35 . 1.29
1.67 . 1.61 . 1.54 . 1.47 . 1.41 . 1.35
1.73 . 1.66 . 1.59 . 1.52 . 1.46 . 1.40
1.79 . 1.72 . 1.64 . 1.58 . 1.48 . 1.45
1.84 . 1.77 . 1.69 . 1.63 . 1.57 . 1.50
1.89 . 1.82 . 1.75 . 1.68 . 1.62 . 1.55
1.94 . 1.87 . 1.80 . 1.73 . 1.67 . 1.55
1.99 . 1.92 . 1.85 . 1.78 . 1.72 . 1.65
2.04 . 1.97 . 1.90 . 1.84 . 1.77 . 1.70
2.09 . 2.02 . 1.95 . 1.89 . 1.82 . 1.75
2.14 . 2.07 . 2.00 . 1.93 . 1.87 . 1.81
2.19 . 2.12 . 2.05 . 1.98 . 1.92 . 1.85
2.23 . 2.16 . 2.10 . 2.03 . 1.96 . 1.90
2.27 . 2.21 . 2.14 . 2.08 . 2.01 . 1.95
2.32 . 2.25 . 2.19 . 2.12 . 2.06 . 2.00
2.36 . 2.30 . 2.23 . 2.17 . 2.10 . 2.04
2.42 . 2.34 . 2.28 . 2.21 . 2.15 . 2.08
2.45 . 2.39 . 2.32 . 2.25 . 2.19 . 2.13
2.50 . 2.43 . 2.36 . 2.29 . 2.23 . 2.17
____ . ____ . ____ . ____ . ____ . ____
1.12 . ____ . ____ . ____ . ____ . ____

1.21 . ____ . ____ . ____ . ____ . ____
1.31 . 1.19 . ____ . ____ . ____ . ____
1.40 . 1.30 . 1.17 . ____ . ____ . ____
1.49 . 1.37 . 1.28 . 1.16 . ____ . ____
1.57 . 1.47 . 1.37 . 1.26 . 1.15 . ____
1.66 . 1.56 . 1.45 . 1.36 . 1.26 . 1.14
1.75 . 1.64 . 1.54 . 1.44 . 1.35 . 1.24
1.83 . 1.73 . 1.62 . 1.52 . 1.43 . 1.34
1.92 . 1.81 . 1.71 . 1.61 . 1.51 . 1.42
2.01 . 1.90 . 1.79 . 1.69 . 1.60 . 1.50
2.10 . 1.98 . 1.88 . 1.77 . 1.67 . 1.58
2.19 . 2.07 . 1.96 . 1.86 . 1.75 . 1.66
2.27 . 2.16 . 2.05 . 1.94 . 1.84 . 1.74
2.36 . 2.24 . 2.14 . 2.03 . 1.92 . 1.83
2.45 . 2.33 . 2.21 . 2.11 . 2.00 . 1.90
2.53 . 2.42 . 2.30 . 2.19 . 2.09 . 1.98
2.63 . 2.50 . 2.39 . 2.27 . 2.17 . 2.06
2.75 . 2.59 . 2.47 . 2.37 . 2.25 . 2.15
2.83 . 2.69 . 2.55 . 2.44 . 2.34 . 2.23
2.96 . 2.78 . 2.65 . 2.54 . 2.42 . 2.32
3.07 . 2.90 . 2.76 . 2.62 . 2.50 . 2.40

3.17 . 3.00 . 2.86 . 2.71 . 2.59 . 2.47
3.29 . 3.14 . 2.97 . 2.81 . 2.68 . 2.56
3.40 . 3.24 . 3.07 . 2.83 . 2.78 . 2.65
____ . 3.35 . 3.19 . 3.03 . 2.87 . 2.75
____ . 3.45 . 3.29 . 3.14 . 2.97 . 2.83
____ . ____ . 3.39 . 3.24 . 3.09 . 2.93
____ . ____ . ____ . 3.32 . 3.19 . 3.03
____ . ____ . ____ . 3.43 . 3.28 . 3.14
____ . ____ . ____ . 3.32 . 3.19 . 3.03
____ . ____ . ____ . 3.63 . 3.28 . 3.14
77......+...90....+....0....+...10....+..

Appendix 1.
3228. (i) [FN1] Boiler, Furnace and Incinerator Rooms.
Any room containing a boiler, furnace, incinerator, or other fuel-fired equipment must be provided with two means of egress when both of the following conditions exist:
(1) The area of the room exceeds 500 square feet, or

(2) The largest single piece of fuel-fired equipment exceeds 1,000,000 B.t.u. per hour input capacity.
Exception: Rooms housing high-pressure boilers (greater than 15 lbs. psi) where either of the conditions listed in (1) or (2) exist shall be provided with 2 exits.
If two means of egress must be provided, one may be a fixed ladder. The means of egress must be separated by a horizontal distance not less than half the greatest horizontal dimension of the room. All openings shall be protected with a self-closing fire assembly having a minimum one-hour fire-protection rating. Where oil-fired boilers are used, a 6-inch noncombustible sill (dike) shall be provided. There shall be no interior openings between any occupancy where flammable or explosive concentrations may be expected to accumulate.
[FN1] Reprint of General Industry Safety Order, Section 3228(i), Exits, Boiler, Furnace and Incinerator Rooms, of the California Administrative Code, Title 8, Subchapter 7 (Register 72, No. 23).
3274. [FN2] Valves and Controls.

(a) Where pipe valves require daily manipulation and are so located that they cannot be reached or operated from the floor, a permanent platform or other safe means of operation shall be provided.
(b) Valves or other controls shall not be so located that their manipulation exposes the employee to hazards of dangerous moving parts of prime movers, machines, or transmission equipment. (Title 24, T8-3274)
[FN2] Reprint of General Industry Safety Order, Section 3274, Valves and Controls, of the California Administrative Code, Title 8, Subchapter 7 (Register 76, No. 29).
3311. [FN3] Flarebacks.
(a) To provide greater safety in lighting and relighting fixed fired equipment, the employer shall designate one or more employees who shall be trained in the safe lighting and relighting of the equipment. It shall be the responsibility of the employer to limit lighting and relighting of the equipment to employees so designated. It shall be the responsibility of the employees to follow the instructions given them. Copies of the instructions shall be prominently displayed at a location near the equipment.

(b) In addition to the above fire boxes or combustion chambers shall be purged or allowed sufficient time to vent themselves before a source of ignition is introduced into them.
(c) Provision shall be made, for the furnishing of extension lighting rods, where their use is indicated. Valves and other controls shall be so located as to avoid placing the employee in an unsafe position if a flareback occurs.
[FN3] Reprint of General Industry Safety Order, Section 3311, Flarebacks, of the California Administrative Code, Title 8, Subchapter 7 (Register 72, No. 23).
3312. [FN4] Entering Combustion Chambers, Flues, Boilers or Unfired Steam Pressure Vessels.
(a) Before employees are allowed to enter, through a manhole, the shell or drum of a steam boiler or an unfired steam pressure vessel for maintenance or repair, where such a boiler or pressure vessel is one of a battery of two or more boilers or vessels or is connected to another source of steam, the valves connecting to the steam header or other source of steam shall be closed and effectively blinded or two valves shall be installed with a bleeder between them and the valves shall be closed and bleeder open. Blow down valves and other valves on lines through which harmful material might accidentally flow back to the boiler or vessel shall be either sealed or closed and locked and the key retained by the em ployee or his supervisor while the employee is in the boiler or vessel. When lines are effectively blinded the valves need not be locked or sealed.
(b) Employees shall not enter or be required to enter the fire boxes, flues or combustion chambers of fired apparatus until:
(1) The pilot light, fuel and steam lines to burners entering the fire box or combustion chamber have been blinded, disconnected or effectively closed by the use of two block valves with an open bleeder between them.
(2) All probability of ignition of any solid combustibles in the fire box or combustion chamber has been removed.
[FN4] Reprint ofGeneral Industry Safety Order, Section 3312, Entering Combustion Chambers, Flues, Boilers or Unfired Steam Pressure Vessels, of the California Administrative Code, Title 8, Subchapter 7 (Register 72, No. 23). (continued)