National Aeronautics and Space Administration — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation 1200 New Jersey Avenue, SE Washington, D.C. 20590 Materials Safety Pipeline and Hazardous Administration JUL 1 4 2016 Mr. Russell Clautice ESH&Q, Institutional Services Contract URS Federal Technical Services, Inc. National Aeronautics and Space Administration Kennedy Space Center P.O. Box 21025, M/C: ISC-8000 Florida 32815-0025 Reference No. 16-0047 Dear Mr. Clautice: This responds to your February 23, 2016 email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR parts 171-180). Specifically you ask if a weight scale used in lieu of a burette to measure water displacement in hydrostatic testing of compressed gas cylinders is required to be calibrated. In accordance with 49 CFR 180.205(g)(3), each day before restesting, a cylinder retester is required to use a calibrated cylinder or other method authorized in writing by the Associate Administrator to verify the accuracy of a hydrostatic retest system, including both the pressure- indicating device and the expansion-indicating device (EID). The pressure-indicating device, as part of the retest apparatus, must be accurate within =1.0% of each individual test pressure to be tested that day. The expansion-indicating device, as part of the retest apparatus, gives a stable reading of expansion and is accurate to ‡1.0% of the total expansion of any cylinder to be tested that day or 0.1 cc, whichever is larger.' However, if the pressure indicating device or EID, as applicable, is not in compliance with an accuracy of t0.5%, or better, of its full range, retesting is not permitted on that day. Section 180.205(g)(4) specifies that the calibrated cylinder must show no permanent expansion. This is a separate requirement and is not related to the test equipment ‡1.0% accuracy requirement. This means that the water level in the burette or the weigh bowl must return to the same point where it began - not slightly higher or lower. After depressurization of the calibrated cylinder, all of the displaced water must return to the water jacket. Any volume of water measured in the EID above zero (or the original reading) indicates permanent expansion of the calibrated cylinder. 1 This requirement cannot be met without a calibrated weight scale. For frequency of calibration, consult the manufacturer's guidelines as indicated in Compressed Gas Association (CGA) C-1, Appendix B-B3.#

Page 22 If this occurs, the equipment has not been proven to be accurate in accordance with the HMR. With regard to your reference to CGA C-1, currently the HMR do not incorporate the publication by reference. We may consider incorporating by reference this publication or certain provisions of the CGA C-1 publication in a future rulemaking. I hope this satisfies your inquiry. Please feel free to contact us if we can be of further assistance. Sincerely, DuaneA.Pf. Duane A. Pfund International Standards Coordinator Standards and Rulemaking Division#

Page 3Antonelli Goodall, Shante CTR (PHMSA) 1380 eneral reguremenk From: Geller, Shelby CTR (PHMSA) 16-0047 Sent: Monday, March 14, 2016 9:36 AM To: Hazmat Interps Subject: FW: Letter of Interpretation Request Dear Shante and Alice, I also wanted to follow up on Mr. Clautice's request as it was not in the database either. Thanks, Shelby From: Geller, Shelby CTR (PHMSA) Sent: Tuesday, February 23, 2016 3:13 PM To: Hazmat Interps Subject: FW: Letter of Interpretation Request Dear Shante and Alice, Forwarded is a request for a letter of interpretation. Mr. Clautice spoke with both Jordan Rivera and Steve Andrews in the HMIC. Thanks, Shelby From: Clautice, Russell L. (KSC-ISC-1160)[URS Federal Services, Inc.] [mailto: russell.l.clautice@nasa.gov] To: INFOCNTR (PHMSA) Sent: Tuesday, February 23, 2016 8:38 AM Services, Inc.]; Adamson, Thomas D. (KSC-ISC-1160)[URS Federal Services, Inc.]; Richard Boggs Cc: Clautice, Russell L. (KSC-ISC-1160)[URS Federal Services, Inc.]; Case, Dennis R. (KSC-ISC-1160)[URS Federal Subject: Letter of Interpretation Request To Whom it may concern: I have a question concerning the calibration requirements of the weight scale used during hydrostatic testing of compressed gas cylinders. Specifically, when a weight scale is used to measure water displacement in lieu of a burette, is the scale required to be calibrated? I have researched the 49CFR and couldn't locate any information. I also have researched CGA C-1 and identified the following statement in Appendix B, B3 Expansion Indicating device: "For digital devices, consult the manufacturer's guidelines for recalibration." I have discussed this question with a "Cylinder Engineer" at DOT and was told that the cylinder retester is required to maintain calibration on the weight scale by following the requirements of CGA C-1. In addition, the Cylinder Engineer informed me that CGA C-1 is in the process of becoming a reference document. Thank You, Russ Clautice ESH&Q, Institutional Services Contract (ISC) 1#

Page 4NASA, Kennedy Space Center © 321-403-6723 russell..clautice@nasa.gov P.O. Box 21025, M/C: ISC-8000, Kennedy Space Center, Florida 32815-0025 URS Federal Technical Services, Inc T 1-321-403-6723 F 1-321-861-4222 www.aecom.com#