Railroad Commission of Texas — Hazardous Materials Safety Interpretation

Page 1of Transportation U.S. Department 400 Seventh Street. S.W Washington, D.C. 20590 Research and Special Programs Administration DEC - 6 2000 Ref. No. 00-0334 Mr. Cleveland O'Brien Propane Technologies Training Instructor Railroad Commission of Texas 1701 North Congress Austin, Texas 78701 • Dear Mr. O'Brien: This responds to your request for clarification of the requirements applicable to non-specification cargo tanks operating under the provisions of § 173.315(k) of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, you ask whether a non-specification cargo tank equipped with excess flow valves in the vapor and liquid discharge openings must be.. equipped with an internal self-closing stop valve at the first leakage test after July 1, 1999. The answer is no. Section 180.405(n) of the HMR requires non-specification cargo tanks conforming to § 173.315(k) to be equipped with a means of thermal activation for the internal self-closing stop valve by the date of its first scheduled leakage test after July 1, 1999. The thermal activation device must meet the requirements for thermal remote operators in § 178.337-8(a)(4). This requirement does not apply to a non-specification cargo tank authorized under § 173.315(k) that is not currently equipped with an internal self-closing stop valve. Although a non-specification cargo tank that does not have an internal self-closing stop valve need not be retrofitted with a thermal activation device at this time, it will be necessary to install such a device as part of the emergency discharge control system retrofit program required under §180.405(m). This section requires a non-specification cargo tank authorized under § 173.315(k) to be equipped with an emergency discharge control capability as specified in § 173.315(n) at the date of its first scheduled pressure test after July 1, 2001. Section 173.315(n) requires each cargo tank used to transport liquefied compressed gas to have an emergency discharge control capability. For each cargo tank operating in metered delivery service, as defined in § 171.8, with a capacity of 3,500 gallons or less, the emergency discharge control capability consists of an off- truck means to close the internal self-closing stop valve and shut off all motive and auxiliary "power (see § 173.315(n)(3)). Thus, at the date of its first scheduled pressure test after July 1, 2001, each non-specification cargo tank operating under § 173.315(k) in metered delivery service must be equipped with an internal self-closing stop valve and an off-truck means to close#

Page 2the valve and shut off all motive and auxiliary power. When the internal self-closing stop valve is installed, each non-specification cargo tank must also be equipped with a means of thermal activation for the internal self-closing stop valve in accordance with § 180.405(n). I hope this information is helpful. If you have further questions, please do not hesitate to contact this office. Sincerely, Edward T. Mazzullo Director, Office of Hazardous Materials Standards#

Page 3= 7 DRAFT Question: The Implementation Schedule of thermal links on Internal Valves? In reterence to 49 CFR 180.405(n), does a non-specification unit complying with 49 CFR 173.315(k) equipped with excess flow valves in the vapor and liquid discharge openings required to be equipped with internal valves at the first leakage test after July 1, 1999? Is there anything to prevent these non-specification units to remain in LP-gas service until the next pressure test whereby the emergency discharge safety equipment and the required the off-truck remote will be installed in accordance with the implementation schedule (HM225A)? Background Of the approximate 4,000 LP-gas transportation units currently registered with the Commission, about 650 of these units are non-specification units which comply with 49 CFR 173.315(k). A large percentage of these 650 units are equipped with excess flow valves. To remove such units at this time of year will cause a severe hardship on the general public, the operating entities, and other applicable parties. There are insufficient entities at this time to meet the restricted time line as stated by 49 CFR 180.405(n). The Railroad Commission (Commission) is statutorily responsible for LP-gas safety in Texas. Part of this responsibility requires transports and bobtails used to transport LP-gas in Texas to be registered with the Commission. Respectively Submitted The estimated economic impact is $2,250,000 for 500 units and $4,500 cost per truck to install the internal valves and redo the piping system. While there are 650 non-spec trucks we estimate that there are about 500 units that need to be retrofitted. Cleveland O'Brien, Propane Technologies Training Instructor Thomas D. Petru, Technical Advisor (LP-Gas, CNG, LNG) Railroad Commission of Texas#