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Below are the available interpretations and guidance for the given section. To return to the list of parts, use the Parts link above. If you do not see any guidance or interpretation information below, that means there is none available for the given part/section. Return to the search page to browse additional regulations sections.

PHMSA has published several Frequently Asked Questions (FAQ) documents on regulatory topics. Please review our FAQ documents below:

Additionally PHMSA has Hazardous Materials FAQs based on letters of interpretation on the following topics:

This section of the website provides the ability to find regulations information including regulations parts, content of sections, and interpretations for regulations sections. Below is a list of parts, identified by the part number and subject. To browse sections by part, click on the subject link below. You will be taken to the eCFR website to view sections for a part.

A written regulatory interpretation, response to a question, or an opinion concerning a pipeline safety issue may be obtained by submitting a written request to the Office of Pipeline Safety (PHP–30), PHMSA, U.S. Department of Transportation, 1200 New Jersey Avenue SE., Washington, DC 20590–0001 or at the email address: In addition to email address, the requestor must include his or her return address and should also include a daytime telephone number. Requests should be submitted at least 120 days before the time the requestor needs a response.

Note: electronic submission is provided as alternative to the 49 CFR Part 190.11(b) mail-in requirement.

The regulations text of the section can be found on the eCFR website. To view the regulations text, use the link below. For assistance, please send an email to

View part 193 on the ECFR website

Interpretation Responses

Ref ID Date Company Name Individual Name Response Document
PI-18-0021 IHI E&C International Corporation Mr. Don Boudreaux View
PI-18-0008 IHI E&C International Corp. Mr. Thomas Donaldson View

Regulation Sections

Section Subject
193.2001 Scope of part
193.2005 Applicability
193.2007 Definitions
193.2009 Rules of regulatory construction
193.2011 Reporting
193.2013 What documents are incorporated by reference partly or wholly in this part?
193.2017 Plans and procedures
193.2019 Mobile and temporary LNG facilities
193.2051 Scope
193.2057 Thermal radiation protection
193.2059 Flammable vapor-gas dispersion protection
193.2067 Wind forces
193.2101 Scope
193.2119 Records
193.2155 Structural requirements
193.2161 Dikes, general
193.2167 Covered systems
193.2173 Water removal
193.2181 Impoundment capacity: LNG storage tanks
193.2187 Nonmetallic membrane liner
193.2301 Scope
193.2303 Construction acceptance
193.2304 Corrosion control overview
193.2321 Nondestructive tests
193.2401 Scope
193.2441 Control center
193.2445 Sources of power
193.2501 Scope
193.2503 Operating procedures
193.2505 Cooldown
193.2507 Monitoring operations
193.2509 Emergency procedures
193.2511 Personnel safety
193.2513 Transfer procedures
193.2515 Investigations of failures
193.2517 Purging
193.2519 Communication systems
193.2521 Operating records
193.2601 Scope
193.2603 General
193.2605 Maintenance procedures
193.2607 Foreign material
193.2609 Support systems
193.2611 Fire protection
193.2613 Auxiliary power sources
193.2615 Isolating and purging
193.2617 Repairs
193.2619 Control systems
193.2621 Testing transfer hoses
193.2623 Inspecting LNG storage tanks
193.2625 Corrosion protection
193.2627 Atmospheric corrosion control
193.2629 External corrosion control: buried or submerged components
193.2631 Internal corrosion control
193.2633 Interference currents
193.2635 Monitoring corrosion control
193.2637 Remedial measures
193.2639 Maintenance records
193.2701 Scope
193.2703 Design and fabrication
193.2705 Construction, installation, inspection, and testing
193.2707 Operations and maintenance
193.2709 Security
193.2711 Personnel health
193.2713 Training: operations and maintenance
193.2715 Training: security
193.2717 Training: fire protection
193.2719 Training: records
193.2801 Fire protection
193.2901 Scope
193.2903 Security procedures
193.2905 Protective enclosures
193.2907 Protective enclosure construction
193.2909 Security communications
193.2911 Security lighting
193.2913 Security monitoring
193.2915 Alternative power sources
193.2917 Warning signs