Railroad Commission of Texas — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration S~p 1 3 2011 1200 New Jersey Ave" S.E. Washington, DC 20590 Mr. James Osterhaus Railroad Commission of Texas 1701 N. Congress Austin, TX 78711 Ref. No.: 11-0055 Dear Mr. Osterhaus: This responds to your March 3, 2011 letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to M C 331 cargo tanks. Specifically, you ask if the HMR permit the use of an excess flow valve and a manual shutoff valve instead of an internal self-closing stop valve for MC 331 tanks with vapor or liquid discharge openings greater than 1 '14 NPT, but have been modified using a bushing to reduce the opening to less than 1 '14 NPT. Under the HMR, an internal self-closing stop valve is not required for an MC 331 tank if the vapor or liquid discharge opening is less than 1 '14 NPT (National Pipe Thread) and is equipped with an excess flow valve together with a manually operated external stop valve (§ 178.337-8(a)(5)(i». However, a change to the size ofthe opening on an MC 331 cargo tank is considered a modification to the cargo tank and must satisfy all ofthe requirements of the HMR that apply to cargo tank modification. Accordingly, the modification must be performed by a repair facility holding a valld National Board Certificate of Authorization for use of the National Board "R" stamp (§ 180.413(a)(I», and the design ofthe modified cargo tank motor vehicle must be certified in writing by a Design Certifying Engineer as meeting the structural integrity and accident damage protection requirements of the applicable specification (§ 180.413( d)(1 ». Also, the person performing the modification must be registered with the Federal Motor Carrier Safety Administration in accordance with Part 107, Subpart F (§ 180.413(a)(3». I trust this satisfies your inquiry. Please contact us if we can be of further assistance. Ben Supko Acting Chief, Standards Development Branch Standards and Rulemaking Division#

Page 2Drakeford, Carolyn (PHMSA) From: INFOCNTR (PHMSA) 1/-0055 Sent: Thursday, March 03, 2011 12:26 PM To: Drakeford, Carolyn (PHMSA) Subject: FW: Hazmat Information Center Feedback: Highway (Sections 177.800 – 177.870) Hi Carolyn, Mr. Osterhaus requested the below e-mail be submitted as a formal letter of interpretation. He previously spoke with Chris Ludwa in the Info Center. Thanks, Victoria Victoria Lehman Hazmat Information Center (HMIC) Pipeline & Hazardous Materials Safety Administration 1200 New Jersey Avenue, SE, E21-119 Washington, D.C. 20590 http://phmsa.dot.gov/hazmat/info-center (202) 366-1035 -----Original Message----From: PHMSA-Feedback [mailto:PHMSA-Feedback] Sent: Wednesday, March 02, 2011 3:05 PM To: PHMSA HM InfoCenter; PHMSA Webmaster Subject: Hazmat Information Center Feedback: Highway (Sections 177.800 &ndashj 177.870) Secion 178.337-8(a)(5)(i)allows the use of an excess flow valve and a manual shutoff valve instead of an internal self-closing stop valve for MC 331 container openings of less than 11/4 inch. If an MC331 container is manufactured with a 11/4 inch or larger opening and a bushing is installed in the opening to reduce the opening to a size less than 11/4 inch, is it acceptable to install an excess flow valve and a manual shutoff valve instead of an internal self-closing stop valve? Name: James Osterhaus Organization: Railroad Commission of Texas Email: james.osterhaus@rrc.state.tx.us Address: 1701 N. Congress City: Austin Zip Code: 78711 Phone: 512-463-6692 FAX: 512-463-0649 1#