(a) Repairs and alterations shall conform to the current edition of the National Board Inspection Code (NBIC) and shall be acceptable to the inspector, except that repairs and alterations may be performed by the following, provided the intended work is within the scope of the issued certificate of authorization:      
        (1) holders of a certificate of authorization from the National Board of Boiler and Pressure Vessel Inspectors for use of the R repair symbol stamp; or       
        (2) owner/operators of boilers who have been issued a certificate of authorization by the department.                  (A) Issuance of the certificate of authorization will be made upon submission of an application, on forms provided by the department.                   (B) Review of the applicant's program and facilities initially and at subsequent three-year intervals will be done.                      (i) The review will determine the applicant has a documented program to control repairs and/or alterations conforming to minimum requirements established by the department.                       (ii) The review will require demonstration of the applicant's ability to perform repairs and/or alterations by implementing on representative work the requirements of the written program.                       (iii) The guidelines of the NBIC for the quality control system are a minimum, except that an Authorized Inspection Agency is not required and the Repair and Alteration forms are issued by the department. The National Board's forms shall not be used by these certificate holders.           
      (b) Derating a boiler's MAWP and/or allowable temperature (in accordance with the NBIC), shall be approved by the department prior to commencement of the alteration. If the derating is approved, the MAWP and/or allowable temperature shall not be increased without prior approval from the department.     
      (c) Non-welded repairs.      
        (1) Replacement parts made of plate material used for pressure retaining shall require material test reports (MTR). Traceability to the MTR must be maintained at all times.       
        (2) Replacement parts fabricated by welding shall be certified, stamped with the appropriate ASME Code symbol and inspected by an authorized inspector as required by the ASME Code.       
        (3) When a non-welded repair involves the replacement of cast or forged parts that are identified with the ASME Code symbol at the time of casting or forging, these parts shall be replaced with cast or forged parts that are identified with the ASME Code symbol or so certified by the manufacturer to be in accordance with the original code of construction.       
        (4) All other materials shall not require MTR's, provided the material is identified with the material specification, grade, lot and rating as required by the material or product specification and the ASME Code.       
        (5) When used parts are utilized for non-welded repairs, it is the repair organization's responsibility to ensure the parts are identified as required above.       
        (6) Boiler tubes shall be replaced with tubes of the allowed material and in accordance with the original code of construction.       
      (d) Lap seam cracks. The shell or drum of a boiler in which a typical lap seam crack is discovered along a longitudinal riveted lap-type joint shall be immediately and permanently discontinued for use under pressure. A lap seam crack is the typical crack frequently found in lap seams, which extends parallel to the longitudinal joint and is located either between or adjacent to rivet holes.     
      (e) Plugging of boiler tubes (excluding tubes in headers of economizers, evaporators, superheaters, or reheaters).      
        (1) Tube plugs shall be made of a material which is compatible with the material of the boiler tube being plugged and shall be welded into place, or manufactured to be expanded into the tube sheet or drum.       
        (2) Plugging boiler tubes on Fire Tube Boilers fabricated in accordance with ASME Section I or IV. Best practice is not to plug a boiler tube in a Fire Tube Boiler. If a Fire Tube Boiler tube is plugged, the following criteria shall apply.                  (A) Plugging boiler tubes that are adjacent to another plugged boiler tube is prohibited.                   (B) No more than 10% of the total number of boiler tubes shall be plugged.                   (C) All non-expanded boiler tube plugs shall be welded into place.                   (D) All plugged boiler tubes shall be replaced prior to the next required Certificate Inspection.         
        (3) Plugging boiler tubes on Water Tube Boilers, Unfired Boilers, or Process Steam Generators.                  (A) No more than 10% of the boiler generating tubes may be plugged. Additional tubes may be plugged after approval is obtained from the Original Equipment Manufacturer or an Engineer experienced in boiler design. The scope of the approval is limited to the plugging of the tubes and shall consider the operational effect on the water side pressure boundary or membrane and the effect on the combustion process throughout the boiler.                   (B) No Water Wall tubes may be plugged, where the tube forms a separation wall between products of combustion and the outside atmosphere or a separation of the gas passes in a multiple (gas) pass boiler.         
     Source Note:        The provisions of this §65.612 adopted to be effective June 15, 2015, 40 TexReg 3121; amended to be effective February 15, 2016, 41 TexReg 795; amended to be effective February 15, 2019, 44 TexReg 583