{"operation":"document","citation":"68 FR 19258","title":"Hazardous Materials: Requirements for Cargo Tanks","source_type":"rulemaking","agency":"Research and Special Programs Administration","status":"historical","official":true,"published_on":"2003-04-18","effective_on":"2003-10-01","summary":"RSPA is adopting a number of revisions to the Hazardous Materials Regulations to update and clarify the regulations on the construction and maintenance of cargo tank motor vehicles. This final rule also addresses three National Transportation Safety Board (NTSB) recommendations and several petitions for rulemaking. These revisions will increase the safety of cargo tanks transporting hazardous materials, provide greater flexibility in design and construction of cargo tanks, and reduce operating burdens for owners, operators, and manufacturers of cargo tank motor vehicles.","machine_formats":{"json":"https://regulus.evalyn.ai/document/federal-register-03-9070.json","markdown":"https://regulus.evalyn.ai/document/federal-register-03-9070.md"},"app_url":"https://regulus.evalyn.ai/document/federal-register-03-9070","source_url":"https://www.federalregister.gov/documents/2003/04/18/03-9070/hazardous-materials-requirements-for-cargo-tanks","body":"Federal Register, Volume 68 Issue 75 (Friday, April 18, 2003) [Federal Register Volume 68, Number 75 (Friday, April 18, 2003)] [Rules and Regulations] [Pages 19258-19291] From the Federal Register Online via the Government Publishing Office [ www.gpo.gov ] [FR Doc No: 03-9070] [[Page 19257]] ----------------------------------------------------------------------- Part II Department of Transportation ----------------------------------------------------------------------- Research and Special Programs Administration ----------------------------------------------------------------------- 49 CFR Parts 107, 171, et al. Hazardous Materials: Requirements for Cargo Tanks; Final Rule Federal Register / Vol. 68, No. 75 / Friday, April 18, 2003 / Rules and Regulations [[Page 19258]] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Research and Special Programs Administration 49 CFR Parts 107, 171, 172, 173, 177, 178, and 180 [Docket No. RSPA-98-3554 (HM-213)] RIN 2137-AC90 Hazardous Materials: Requirements for Cargo Tanks AGENCY: Research and Special Programs Administration (RSPA), DOT. ACTION: Final rule. ----------------------------------------------------------------------- SUMMARY: RSPA is adopting a number of revisions to the Hazardous Materials Regulations to update and clarify the regulations on the construction and maintenance of cargo tank motor vehicles. This final rule also addresses three National Transportation Safety Board (NTSB) recommendations and several petitions for rulemaking. These revisions will increase the safety of cargo tanks transporting hazardous materials, provide greater flexibility in design and construction of cargo tanks, and reduce operating burdens for owners, operators, and manufacturers of cargo tank motor vehicles. DATES: Effective date: This final rule is effective October 1, 2003. Voluntary compliance date: Voluntary compliance is authorized 30 days following publication of this final rule. Incorporation by reference date: The incorporation by reference of publications listed in this final rule has been approved by the Director of the Federal Register as of October 1, 2003. FOR FURTHER INFORMATION CONTACT: Mr. Michael Johnsen, Hazardous Materials Division, Federal Motor Carrier Safety Administration (FMCSA), telephone (202) 366-6121; Mr. Philip Olson, Office of Hazardous Materials Technology, RSPA, telephone (202) 366-4504; Ms. Susan Gorsky, Hazardous Materials Standards, RSPA, telephone (202) 366- 8553; or Mr. Danny Shelton, Office of Enforcement and Program Delivery, Hazardous Materials Division, Federal Motor Carrier Safety Administration (FMCSA), telephone (202) 366-6121. SUPPLEMENTARY INFORMATION: I. Background II. Revisions Applicable to All Cargo Tanks A. Definitions B. Marking of Emergency Shutoff Devices C. Recertification to Original Specification D. Cargo Tank Qualification and Maintenance III. Revisions Applicable to DOT 400-Series Cargo Tanks A. Structural Integrity Requirements B. Manhole Marking C. Road Clearance D. MAWP Specification Plate Marking E. Leak Testing Using EPA Method 27 F. Weld Joints on DOT 407 Cargo Tanks IV. Revisions Applicable to MC 331 and MC 338 Cargo Tanks A. Consistency with DOT 400-series Specification B. Remote Shutoffs C. Inlet and Outlet Fittings on MC 331 Cargo Tanks D. Internal Visual Inspections of Insulated Tanks E. Leakage Tests for Cargo Tanks in Anhydrous Ammonia Service V. Section-by-Section Review VI. Rulemaking Analysis and Notices A. Executive Order 12866 and DOT Regulatory Policies and Procedures B. Executive Order 13132 C. Executive Order 13175 D. Regulatory Flexibility Act E. Paperwork Reduction Act F. Regulation Identifier Number (RIN) G. Unfunded Mandates Reform Act H. Environmental Assessment I. Background On June 12, 1989, the Research and Special Programs Administration (RSPA; we) published a final rule in the Federal Register (Docket HM- 183, 183A; 54 FR 24982) that revised the Hazardous Materials Regulations (HMR; 49 CFR Parts 171 through 180) pertaining to cargo tank motor vehicles. We further revised the regulations each year from 1990 through 1995 under dockets HM-183, HM-183A, and HM-183C. Several of these dockets made significant changes to the cargo tank regulations to improve safety; other revisions corrected mistakes and made minor changes. Dockets HM-183 and 183A established the DOT 400 series cargo tank specifications, as well as certification requirements for cargo tank manufacturers. Docket HM-183C contained a number of miscellaneous items that clarified and relaxed certain requirements for the manufacture, qualification, and maintenance of cargo tank motor vehicles. Under 49 CFR 1.73(d), the Federal Motor Carrier Safety Administration (FMCSA) is delegated authority to enforce the Hazardous Materials Requirements (HMR), with particular emphasis on highway transportation, including regulations for construction and maintenance of cargo tank motor vehicles (CTMVs). FMCSA and RSPA work closely with the regulated industry through educational assistance activities and FMCSA's compliance and enforcement program. As a result of these activities, we identified several areas in the current regulations that need updating or clarification. The Cargo Tank Technical Assistant Group, comprised of state enforcement officials along with members of FMCSA and RSPA, also identified areas where cargo tank regulations could be improved for safety or clarified to facilitate compliance. In addition, we received requests for clarification of the regulations and petitions for rulemaking. The National Transportation Safety Board (NTSB) has also made several safety recommendations concerning cargo tanks. On December 4, 2001, we published a Notice of Proposed Rulemaking (NPRM; 66 FR 63096), proposing revisions that would apply to all cargo tanks and revisions that would apply to certain specification cargo tanks or cargo tanks used to transport certain ladings. This final rule adopts changes proposed in the NPRM as explained in detail below. II. Revisions Applicable to All Cargo Tanks Under Docket HM-183, we adopted a number of definitions for DOT 400-series specification CTMVs. The definitions apply to all specification CTMVs used to transport hazardous materials. In the NPRM we proposed to combine the definitions currently in Sec. 178.345-1(c) with the definitions in Sec. 173.320 (a) and make them applicable to all specification CTMVs. We received comments on the following issues: A. Definitions Cargo Tank. In the NPRM, we proposed in Sec. 171.8 to add Intermediate Bulk Containers (IBCs) to the list of specifications that are not considered cargo tanks. The North American Transportation Consultants, Inc. (NATC) submitted comments expressing concern that the proposed definition would encourage the use of IBCs as vehicle delivery systems for bulk shipments. NATC asserts that the proposed revisions would permit IBCs to be loaded and unloaded without first being removed from the transport vehicle. NATC asks us to delay adding IBCs to the list of specifications that are not considered cargo tanks until after a safety review of IBC unloading operations permitted under exemption. NATC is not correct. Section 177.834(h) prohibits discharge of any contents of any container, other than a cargo tank or IM portable tank, prior to the removal from the motor vehicle. The proposed definition does not change this prohibition. Thus, unless authorized under exemption, IBCs may not be loaded or unloaded without first being removed from the transport vehicle. In this final rule, we are [[Page 19259]] adopting the revised definition, as proposed. Design Certifying Engineer and Registered Inspector. We proposed to change the requirements for Design Certifying Engineers (DCEs) or Registered Inspectors (RIs) to allow experienced persons to act as DCEs or RIs even if they had not registered by the grandfather clause date of December 31, 1995. DCEs and RIs must still meet the registration requirements in Subpart F of Part 107, which include familiarity with all current regulatory requirements and certification. In addition, the proposed definitions for both a DCE and an RI specify that a DCE and RI must have the knowledge and ability to determine whether a cargo tank design and construction meets the applicable specification. The National Tank Truck Carriers (NTTC) proposed relaxing the RI requirements even further and eliminating the three-year requirement. We disagree. The functions performed by an RI are sufficiently complex that three years' work experience is necessary to assure that an RI has acquired essential knowledge and experience. In this final rule, we are adopting the definitions as proposed, with the addition of language to specify that the work experience requirements refer to cargo tank testing and inspection. Corroded/abraded. Commenters generally support our proposal in the NPRM to clarify the term ``corroded or abraded.'' However, several commenters suggest that this definition does not provide sufficient clarification and could lead to enforcement problems. Baltimore Cargo Tank comments that enforcement personnel ``* * *will be compelled to deem any kind of surface mark on the cargo tank wall* * *'' as meeting the definition as proposed. The American Trucking Associations suggests citations may be issued as a result of paint scratches and other cosmetic blemishes. The use of the term ``corroded or abraded'' relates primarily to a requirement to perform an inspection or test, such as those requirements in Sec. 180.407(e) that require that, if a corroded or abraded area is observed by a visual inspection, it must be thickness tested. In this final rule, we are adopting a definition for ``corroded or abraded,'' to address commenters' concerns. Thus, in this final rule, ``corroded or abraded'' is defined to mean any visible reduction in the material thickness of the cargo tank wall or valve due to pitting, flaking, gouging, or chemical reaction to the material surface that affects the safety or serviceability of the cargo tank. The term does not include cosmetic or minor surface degradation that does not affect the safety or serviceability of the cargo tank. Corrosive to the tank/valve. We proposed to revise the definition of ``corrosive to the tank/valve'' because of the many requests for clarification that we have received. The regulations require additional and more frequent inspections (internal inspection, thickness testing, upper coupler removal and inspection) for CTMVs transporting a lading that may adversely affect tanks or valves, causing leaks and other safety hazards. The reference to Sec. 173.136 (definition of a Class 8 material) in the current definition has caused confusion. We did not intend that lading designated as ``corrosive to the tank/valve'' would be limited to Class 8 materials or to materials that cause corrosion at a rate of 6.25 mm or more per year. Our intent was to include any lading, not just Class 8 materials, that corrodes a tank or valve. Only two commenters addressed this proposal, and both supported the change. Thus, RSPA will adopt the proposed change to the definition of ``corrosive to the tank/valve'' to specify that test data and experience must be used to determine if a specific lading is corrosive to the cargo tank wall or valve. The removal of the reference to Sec. 173.136 is intended to clarify that ``corrosive to the tank/valve'' is not limited to materials with a corrosion rate of 6.25 mm or more per year. Any test data or experience that indicates any amount of corrosion is sufficient to meet the definition. Maximum allowable working pressure (MAWP). The Truck Trailer Manufacturers Association (TTMA) submitted a petition for rulemaking (P-1272) suggesting that a cargo tank's MAWP should be dependent on the physical characteristics of the cargo tank rather than the lading carried in the cargo tank or the method of loading or unloading the cargo tank. In its petition, TTMA notes that a cargo tank manufacturer will not always know the characteristics of the lading that will be transported in the cargo tank and that a manufacturer will not always know the pressure at which the tank will be loaded or unloaded. In its petition, TTMA also asserts that the current regulations have resulted in confusion in the regulated industry as to whether the static head of lading should be included in the MAWP. TTMA notes that Sec. 178.345-1(k) defines MAWP as the largest of: (1) The pressure prescribed for the lading in part 173; (2) the vapor pressure of the most volatile lading at 115[deg] F plus the maximum static pressure exerted by the lading at the maximum lading density plus any pressure exerted by a gas padding; or (3) the maximum pressure in the cargo tank during loading or unloading. TTMA states that it is not clear if the static head is included in the lading pressure prescribed in Part 173 or the loading/unloading pressure. We agree with TTMA that there should be no ambiguity in the HMR as to the meaning of MAWP. We agree that the MAWP should be based on a cargo tank's physical characteristics, but we believe MAWP should also be linked to the requirements of Sec. 173.33 for use by shippers and carriers. The proper matching of the maximum lading pressure conditions defined in Sec. 173.33(c) with the MAWP of a cargo tank by shippers and carriers is critical to providing safety in cargo tank operations. The maximum lading pressure addresses many factors critical to matching a lading to a cargo tank MAWP, including the static head (pressure) generated by a specific lading or the maximum pressure in a tank during loading or unloading. For example, Sec. 173.33(c)(iv) requires the sum of the vapor pressure of the lading at 115[deg] F, plus the tank static head exerted by the lading, plus any pressure exerted by a gas padding, including air, in the tank to be less than or equal to the MAWP of the cargo tank. The pressure defined by this summation is the pressure exerted at the bottom of the tank. When a cargo tank is inverted in a rollover, this pressure is applied to the pressure relief devices installed on the top of the cargo tank. Particularly for large diameter tanks and high-density ladings, this resultant pressure could be sufficient to open the cargo tank's pressure relief devices and release the contents of the tank, even if the tank were undamaged. Thus, it is critical for shippers and carriers to determine that the MAWP of a cargo tank is greater than or equal to maximum lading pressure derived from the conditions specified in Sec. 173.33. Similarly, cargo tank manufacturers should be familiar with the requirements of Sec. 173.33 in order to provide a cargo tank with an MAWP sufficient to meet the needs of shippers and carriers. To strengthen the linkage between Sec. 173.33 and cargo tank MAWP, the NPRM proposed to revise the definition for MAWP to require the MAWP to be greater than or equal to the maximum lading pressure condition prescribed in Sec. 173.33 for each material. The proposal is adopted without change in this final rule. Minimum thickness. We proposed to add in Sec. 178.320 a definition for [[Page 19260]] ``minimum thickness'' to clarify how the minimum head and shell thickness for specification cargo tanks must be determined. The proposal defined ``minimum thickness'' to mean the least of: (1) The thickness required by the original specification; (2) the thickness required to satisfy the structural integrity and accident damage requirements; or (3) the thickness required to satisfy the requirements of the American Society of Mechanical Engineers (ASME) Code, if applicable. This proposal was intended to eliminate confusion as to whether the minimum thickness tables in Sec. 180.407(i) are the governing factor in determining minimum thickness. In consultation with members of the Cargo Tank Technical Assistance Group, coordinated through FMCSA, we determined that the proposed definition did not clearly correlate the minimum thickness of the tank with the tank specification requirements. Therefore, in this final rule, we further clarified the definition to read as follows: Minimum thickness means the minimum required shell and head (and baffle and bulkhead when used as tank reinforcement) thickness needed to meet the specification. The minimum thickness is the greatest of the following values: (1)(i) For MC 330, MC 331, and MC 338 cargo tanks, the specified minimum thickness found in the applicable specification(s) for construction; or (ii) For DOT 406, DOT 407 and DOT 412 cargo tanks, the specified minimum thickness found in Tables I and II of the applicable specification(s); or (iii) For MC 300, MC 301, MC 302, MC 303, MC 304, MC 305, MC 306, MC 307, MC 310, MC 311, and MC 312 cargo tanks, the in-service minimum thickness prescribed in Tables I and II of Sec. 180.407(i)(5), of this subchapter, for the minimum thickness specified by Tables I and II of the applicable specification(s); (2) The thickness necessary to meet with the structural integrity and accident damage requirements of the applicable specification(s); or (3) The thickness as computed per the ASME Code requirements (if applicable). In addition, adding minimum thickness determination criteria for MC 331 and 400 series cargo tanks to Sec. 180.407(i) will increase understanding of the requirements by placing all information concerning the thickness of any cargo tank in one section. Thus, new paragraphs (i)(9) and (i)(10) will be added as follows: (i)(9) For MC 331 cargo tanks constructed before the date of this final rule, minimum thickness shall be determined by the thickness indicated on the ASME form U1A minus any corrosion allowance. For tanks constructed after the date of this final rule, the minimum thickness will be that which is indicated on the specification plate. If no corrosion allowance is indicated on the ASME form U1A, then the thickness of the cargo tank shall be the thickness of the material of construction indicated on the form, with no corrosion allowance. (i)(10) For 400-series cargo tanks, minimum thickness is calculated according to tables in each applicable section for that specification: Sec. 178.346-2 for DOT 406 cargo tanks, Sec. 178.347-2 for DOT 407 cargo tanks, and Sec. 178.348-2 for DOT 412 cargo tanks. Cargo tank design includes calculations using the thickness of the tank shell and heads to determine if the tank would meet the minimum structural design requirements less any corrosion allowance. These calculations include a safety factor of 4 that must be maintained throughout the life of the tank. If corrosion is discovered on the tank and the ASME form U1A of the ASME code indicates the shell is .225 inches thick with no corrosion allowance indicated on the ASME form U1A, then any areas on the tank below that thickness must be repaired prior to placing the tank back in service. Clarifying this will provide test and inspection facilities a specific number to determine the thickness of the tank and should simplify calculating corrosion allowances (if any allowance is indicated). We had also proposed to make a separate paragraph (d) for the definition of ``minimum thickness.'' We determined that this is not necessary; in this final rule, the definition appears after the term as it is listed in the section. In addition, the wording in Sec. 178.337- 3(e) should note that the minimum metal thickness of 0.187 inches for steel and 0.270 inches for aluminum is for tanks with a design pressure of 100 psig. This section outlines regulations for minimum thickness on MC 331 cargo tanks, which are primarily used for the transportation of compressed gasses. Further, we are clarifying that the minimum thickness of the tank shell and heads must be determined using structural design requirements in Section VIII of the ASME Code, or 25% of the tensile strength of the material. B. Marking of Emergency Shutoff Devices In response to NTSB recommendation H-93-34, we proposed to amend the HMR in Sec. 172.328 to require all manually activated on-truck remote shutoff devices for closure of the internal valve to be marked ``Emergency Shutoff.'' The requirement would be effective two years after the publication date of a final rule. Several commenters suggest that we reconsider the size requirement for the marking. TTMA and NTTC recommended that the minimum lettering size should be 0.75'' instead of the proposed 1.5'' height due to the size the overall marking would assume if each letter were 1.5'' high. We agree that the 0.75'' minimum letter height is adequate to communicate the presence of the emergency shutoff. Therefore, this final rule requires the emergency shutoff device marking to be a minimum 0.75'' height. C. Recertification to Original Specification There appears to be confusion in the regulated industry as to whether cargo tanks that have been modified for specialized or non- hazardous materials service may be re-certified for hazardous materials service. In the NPRM, we proposed to allow for the re-certification of a cargo tank to its original specification, provided specific requirements are met. These requirements include documentation to verify that the cargo tank was originally manufactured to a DOT specification, verification by a Registered Inspector that the cargo tank is in compliance with the requirements of the specification, and certification that the cargo tank successfully passed all required tests and inspections. In addition, any repairs performed on MC 306, MC 307, or MC 312 cargo tanks after June 30, 1992, must have been performed in accordance with requirements in Sec. 180.413. An example is an MC 306 cargo tank that has had its internal self- closing stop valve removed so that the cargo tank can be used to transport asphalt. As proposed in the NPRM, Sec. 180.405(b), the cargo tank may be re-certified to its original specification provided an internal shutoff valve is reinstalled, the CTMV meets all other requirements of the specification, and the cargo tank motor vehicle has successfully passed the inspections and tests required in Sec. 180.407(c). NATC, whose comments are supported by several other commenters, opposes allowing the recertification of cargo tanks. NATC suggests that the proposed change could result in an increase in unsafe cargo tanks and confusion on the part of enforcement personnel who would be unable to verify the cargo tank certifications. In addition, NATC expressed concern that the proposal is unfair to companies that requalified cargo tanks prior to August 31, 1995. We do not agree that permitting cargo tanks to be re-certified to their original specifications would lead to an increase in unsafe cargo tanks. However, in this final rule we are adding additional language to clarify and ensure a DCE or [[Page 19261]] RI verifies that the cargo tank conforms to all applicable requirements of the specification in effect at the time the tank was originally constructed and the additional requirements proposed in Sec. 180.405(b)(2). Neither do we agree that enforcement personnel will be unable to verify the cargo tank certification. A cargo tank that is re-certified to the original specification will have records of the work performed on the tank, certifications from appropriate inspectors, and specification plates on the cargo tank that would reflect the same testing and certification data that a newly constructed cargo tank would have. The August 31, 1995 date was placed in the regulations in Sec. 180.405 during the rulemaking process under docket HM-183. This was the cut-off date for the manufacture of MC 307, MC 312, MC 331, and MC 338 specification cargo tanks. This date had been extended several times in the rulemaking process in response to petitions and requests by a number of cargo tank industry representatives who stated that the extra years were needed to complete the transition from the older MC specification cargo tanks to the 400 series specifications HM-183 required. None of the companies that commented on the HM-183 time line suggested that removing this date requirement presented an unfair situation. These companies were in the process of manufacturing new cargo tank motor vehicles, and through the HM-183 rulemaking process, we addressed their concerns by extending the compliance date. Removing this date extension in this rule addresses a different concern and does not create an unfair situation. NATC recommends that RSPA include a provision in Sec. 180.405 to allow a cargo tank to be removed from hazmat service without requiring the de-certification of the cargo tank. A specification cargo tank may be used for non-specification service and remain a specification cargo tank. The plate must be covered or removed only if tests or inspections expire. We do not see a need to further clarify the use of specification cargo tanks outside hazardous materials service. D. Cargo Tank Qualification and Maintenance To reduce confusion in the regulated industry, we proposed a number of clarifications to the requirements in Part 180 for cargo tank qualification and maintenance. We have reviewed the comments that we received concerning the variety of proposals under this topic below. Test and inspection criteria. We proposed to clarify in Sec. 180.407(b) the tests and inspections that must be performed when a cargo tank shows evidence of dents, corroded or abraded areas, or leakage; has sustained damage to an extent that may adversely affect its lading retention capability; or has any other condition that could render it unsafe for the transportation of hazardous materials. Several commenters suggested that this language was too ambiguous and could lead to excessive or unnecessary enforcement. In this final rule, we addressed many of these concerns by further modifying the definition of ``corroded or abraded'' (see discussion under ``Definitions'' above). The proposed language in Sec. 180.407, in conjunction with our revised definition of ``corroded or abraded,'' adds more clarity than the previous language in these sections. This final rule adopts the proposed language for test and inspection criteria. Thickness testing of ring stiffeners and appurtenances. Consistent with an NTSB recommendation (H-95-14), we proposed to revise Sec. 180.407(d)(1) to require thickness testing of ring stiffeners and appurtenances on cargo tanks that are constructed of mild steel, high- strength, low-alloy steel, or aluminum, when the ring stiffeners and appurtenances are installed in a manner that precludes an external visual inspection. NTSB investigated two catastrophic cargo tank failures where thickness testing of the cargo tanks' ring stiffeners might have detected the corrosion that caused the failures. In this final rule, we are adopting this proposal without modification. NATC and the commenters that supported NATC's comments, asked us to clarify how an RI should determine minimum thickness of the ring stiffener since there is no ready reference. The regulatory text describes this procedure. Testing normal vents. We proposed changes to the testing of pressure relief devices in Sec. 180.407(g)(1)(ii) to require self- closing pressure relief valves first to open at the required set pressure and, second, to close and seat to a leak-tight condition when the pressure has dropped to 90 percent of the set-to-discharge pressure or the pressure prescribed for the applicable cargo tank specification. Several comments asked us to better define the test requirements for a normal vent that is a self-closing pressure relief device, but is not an emergency relief device that would be tested at the above criteria. In response, we have clarified that normal vents must be tested accordance with the testing criteria established by the valve manufacturer. This assures testing accuracy because the valves will be tested to the specification to which they were built. Repair, modification, stretching, and rebarrelling. The NPRM proposed to clarify Sec. 180.413 requirements for repair, modification, stretching, or rebarrelling of cargo tanks. We proposed to require facilities to perform repairs, modifications, stretching, or rebarrelling of cargo tanks in conformance with the National Board Inspection Code (NBIC). The NBIC establishes procedures for repairing or modifying pressure vessels. Prior to 1995, the NBIC applied only to tanks with a maximum allowable working pressure (MAWP) of 15 psi or greater. However, in 1995 the applicability of the NBIC was extended to all pressure vessels. In this final rule, we are adopting the clarifications as proposed. Adopting the NBIC requirements for all cargo tank repairs, modifications, stretching, and rebarrelling will provide clarity, consistency, and a greater level of safety. Note, however, that we did not propose and are not adopting requirements for certification by an NBIC Authorized Inspector, completion of the R-1 form, and stamping tanks with the ``R'' stamp for non-ASME cargo tanks. In the NPRM, we proposed to clarify that modification, stretching, or rebarrelling must be inspected and certified by a DCE. We proposed to change the requirements in Sec. 180.413(d)(1) to require the design of the modified, stretched, or rebarrelled cargo tank motor vehicle be certified in writing by a DCE as meeting the structural integrity and accident damage protection requirements of the applicable specification. Baltimore Cargo Tank comments that the proposal may be too restrictive because it appears that a DCE would be required to sign off on small changes. However, the definition of ``modification'' includes only those changes that affect a cargo tank or cargo tank motor vehicle's structural integrity or lading retention capability. Such modifications should be approved by a DCE. Supplemental specification plate. We proposed to revise specification plate requirements to reflect the modification, stretching, or rebarrelling of a cargo tank. We proposed to require a supplemental specification plate to be installed adjacent to the original specification plate. Changes to the original specification plate would not be allowed. The information on the original specification plate should be permanent and not altered, even if modifications are performed by the [[Page 19262]] original manufacturer. This final rule adopts the revisions as proposed. Hose testing. We proposed, in Sec. 180.413(c)(1), to require leak testing when any pipe, valve, hose, or fitting on a cargo tank is repaired or replaced in a process that does not involve welding. We proposed that the test must be done in accordance with Sec. 180.407(g)(1). As noted by the National Propane Gas Association (NPGA), the proposal did not take into account existing exceptions from hose maintenance requirements for cargo tanks in dedicated compressed gas (except for carbon dioxide) service. In this final rule, we revised the proposal to include exceptions for cargo tanks in dedicated compressed gas (except for carbon dioxide) service, requiring them to be tested in accordance with the new or repaired delivery hose assemblies requirements in Sec. 180.416(f), since any repair or replacement falling under Sec. 180.413(c)(1) would also fall under this section. Cleaning and purging before repairs. Because persons have suffered severe injuries or death while performing repairs to cargo tanks that were not properly cleaned and purged, we also proposed in Sec. 180.413(a)(2) to clarify and emphasize that the entire CTMV, including void spaces, piping, and vapor recovery systems, must be cleaned and purged before doing repairs, modifications, stretchings, rebarrellings, or mountings on cargo tanks that transport toxic or flammable lading. NPGA suggests that we specify such cleaning and purging would apply only for welded repairs, not for repairs such as replacement of a valve or fitting located downstream of the primary valves or fittings. Replacing a fitting that does not require welding is not a repair as defined in Sec. 180.403 and therefore would not, under this section, require cleaning and purging of the cargo tank. We are adopting our proposal without changes. NTTC asks us to clarify the terms ``cleaned'' and Apurged.'' This terminology is taken from Sec. 173.29(b)(2)(ii) which discusses conditions that may make a packaging ``empty.'' In this final rule, we added the wording from this paragraph to Sec. 180.413(a)(2) to clarify that all hazardous material must be removed from the cargo tank before repairs are performed. III. Revisions Applicable to DOT 400-Series Cargo Tanks In the NPRM, we proposed several revisions to the specifications applicable to the DOT 400-series cargo tanks. These proposals included revisions to: (1) Structural integrity requirements; (2) manhole marking requirements; (3) road clearance allowances; (4) bottom accident protection; (5) specification plate marking; (6) leak testing alternatives; and (7) weld joints. In addition to these changes, which are described below, we also proposed revisions to the DOT 400-series specifications to make the requirements easier to understand and follow. A. Structural Integrity Requirements In the NPRM, we proposed to add structural support members to the list of attachments to which the structural integrity requirements apply for new construction of DOT-400-series CTMVs in Sec. 178.345- 3(f). In addition, the proposal included requiring mounting pads for the installation of structural members, attachments and appurtenances. We received a number of comments on this proposal, with most commenters suggesting that the proposal would impose significant costs on the industry without significantly enhancing safety. Additionally, several commenters note that excessive welding could damage the tank wall, and that there is no indication that lightweight appurtenances account for accident situations that breach the cargo tank wall. TTMA states that there is no data showing lightweight attachments to be a concern for shell damage, and that ``* * * a typical aluminum DOT 406 cargo tank trailer would require over 5,000 inches of additional welding * * *'' and would increase vehicle weight ``* * * by approximately 350 lbs.'' In addition, TTMA cites several safety issues that could result from excessive welding, including creating cavities that could trap hazardous ladings, creating more heat-affected zones, and possible distortion of the cargo tank wall. We have considered the commenters concerns and are not adding structural support members to the list of attachments to which the structural integrity requirements apply. However, this final rule does include minor editorial clarifications that otherwise do not change the requirements in this section. B. Manhole Marking Under Sec. 178.345-5, the HMR currently require manhole covers to be permanently marked with the manufacturer's name, the test pressure, and a certification that the manhole cover meets HMR requirements. This marking enables cargo tank owners, RIs, and enforcement personnel to verify that the manhole conforms to applicable regulatory requirements. In the NPRM, we proposed to require manhole assemblies to be marked on the outside, where the marking can be seen without opening the manhole cover or fill opening and exposing persons to hazardous materials inside the cargo tank. Two commenters addressed the topic, the Fertilizer Institute and Farmland Industries, Inc. Both supported the proposal. This final rule adopts the proposal as presented in the NPRM. This requirement will become effective one year after the effective date of this final rule. The revised marking requirements apply to newly manufactured cargo tanks and to replacement manhole assemblies on existing cargo tanks. C. Road Clearance In a petition for rulemaking (P-1325), TTMA requested that we lower the minimum road clearance requirements in Sec. 178.345-8 to permit greater flexibility in the design of landing gear, tire carriers, cabinets, and other components near axles. TTMA suggested that such a revision would permit lowering the center of gravity for some CTMVs, which would improve dynamic stability. TTMA stated that it is aware of no situations in which a landing gear failure has punctured a cargo tank. We agreed with TTMA that reducing the center of gravity for CTMVs would be beneficial. Thus, in the NPRM, we proposed to revise the requirements for minimum road clearance for landing gear within 10 feet of an axle to be no less than 10 inches. We proposed to maintain the current clearance requirements for the middle area between axles. The proposed revision would allow landing gear to be lowered by two inches, but would not compromise clearances in the area of a CTMV most vulnerable to contact with the ground--that is, the area midway between a tractor's rear axle and the CTMV rear suspension. In its comments on this issue, TTMA suggests that the ten-inch clearance should be measured when there is no lading in the cargo tank. We disagree, because we are identifying the minimum road clearance. This final rule adopts a ten-inch road clearance, and requires it to be calculated when the tank is fully loaded with its maximum lading. D. MAWP Specification Plate Marking In a petition for rulemaking (P-1212), TTMA asked us to eliminate the [[Page 19263]] maximum loading and unloading pressure marking on the specification plate. We included the proposal in the NPRM. TTMA noted that the volume change of liquids transported in DOT 406, DOT 407, and DOT 412 cargo tanks is small and that the maximum loading and unloading rate is calculated in the design of the cargo tank and identified on the specification plate. We agree that the maximum loading and unloading pressure marking is unnecessary because the maximum loading/unloading pressure is reflected in the MAWP. However, in no situation can the actual pressure in the tank exceed the MAWP. This final rule adopts the provision as proposed. In addition, in Sec. 180.405(k), we proposed to require owners of MC 300, MC 301, MC 302, MC 303, MC 305, MC 306 and MC 312 cargo tanks that have a pressure relief system set at 3 psig to mark or remark the cargo tank with an MAWP or design pressure of not less than 3 psig. NATC says that its field staff found approximately 11% of the MC 306 cargo tanks inspected at one location had no design pressure marked on the specification plates. This revision to the marking requirements will help reduce the number of cargo tanks without a marked design pressure. E. Leak Testing Using EPA Method 27 In the NPRM, we proposed to clarify the parameters in Sec. Sec. 178.346-5, 180.407(h)(2), and 180.415(b)(3) for testing and marking cargo tanks used to transport petroleum distillate fuels and equipped with vapor recovery equipment. Such cargo tanks may be tested in accordance with the Environmental Protection Agency (EPA) ``Method 27-- Determination of Vapor Tightness of Gasoline Delivery Tank Using Pressure-Vacuum Test'' as set forth in Appendix A to 40 CFR part 60. This annual certification test includes both the Method 27 test for vapor tightness of a cargo tank and a pressure test of the tank's internal vapor valve. The revision proposed in the NPRM specified that cargo tanks equipped with vapor collection equipment that are used to transport petroleum distillate fuels may be tested in accordance with 40 CFR 63.425(e) instead of the annual leakage test required under Sec. 180.407 of the HMR. In addition, we proposed that, if the EPA annual certification test in 40 CFR 63.425(e) is used to satisfy the annual leak test requirement, the Method 27 test must be conducted using air. Performing the test using liquid, an alternative allowed by EPA, may mask leakage below the liquid level at the pressure level specified for the test. The EPA Method 27 air test wil","truncated":true,"body_characters":216537}