# BASE Engineering, Inc. — Hazardous Materials Safety Interpretation **Citation:** 02-0079 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2002-03-15 02-0079 response to BASE Engineering, Inc. concerning 173.315. ## Document text <<>> Memorandum U.S. Department of Transportation Research and Special Programs Administration Date: MAR 15 2002 Reply to Attn. of: Gorsky, x69532 Subject: Cargo Tank Emergency Discharge Control Ref. No. 02-0079 From: 'Thomas G. Allan' Senior Transportation Regulations Specialist Office of Hazardous Materials Standards To: William A. Quade Chief of Hazardous Materials Division Federal Motor Carrier Safety Administration This responds to your request for a clarification, by e-mail dated February 14, 2002, related to cargo tank emergency discharge control requirements specified in the Hazardous Materials Regulations (HIMR; 49 CFR Parts 171-180). Specifically, you ask for a clarification of the items that must be addressed in the certification by a Design Certifying Engineer (DCE) of an emergency discharge control system for a cargo tank used to transport liquefied compressed gas. As your email notes, the emergency discharge control requirements in § 173.315(n)(2)(ii) of the HMR require the design for a passive shut-down system (1.e., a means to automatically shut off the ilow of product without the need for human intervention) to be certified by a DCE. The DCE certification must explain how the passive shut-down system operates and must indicate the parameters within which the system is designed to operate. Section 173.315(n)(2)(ii) provides some examples of what is meant by the term "parameters" - temperature, pressure, and types of product. Thus, the certification should indicate the range of temperatures within which the system is designed to operate. Further, the certification should specify whether the system's operation is dependent on the pressure inside the cargo tank during an unloading operation. If so, the certification should specify the pressure above or below which the system may not operate. In addition, the certification should indicate if the system is designed to operate irrespective of the material being transported in the cargo tank. If it is not, the certification should specify the materials for which the system is designed to function. Note that these are illustrative examples only. If there are additional operating conditions that may affect the proper functioning of the emergency discharge control system, the certification should so specify. <<>> 2 Based on the foregoing, it appears that the certification prepared by BASE Engineering, Inc., which you provided with your email, does not conform to the requirements in § 173.315(n) (2)(ii). I hope this information is helpful. If you have further questions, please do not hesitate to contact this office. : # ... <<>> zorsky Billings, Delmer $173.315z Cargo Tanks From: To: Sent: Thursday, February 14, 2002 1:37 PM Shelton, Daniel [Daniel.Shelton@fhwa.dot.gov] 02-0079 Cc: Billings, Delmer Subject: Request for Interpretation Swift, Danny ; Quade, William ; Delorenzo, Joseph Certification of passive certirying independent passive shutdown systems which are designed to Del, please find attached for your review two separate documents meet the requirements of 173.315(n)(2). The regulation in DCE and the certification must consider any specifications of the 1/3.315(n)(2)(ii) states in part that the design must be certified by a to shut off the flow of product operates. It must also outline the original component manufacturer and must explain how the passive means parameters (e.g. temperature, pressure, types of product)......... If you review the certification from Carson Engineering, it appears to meet not only the spirit of the regulations but also the intent of the to fall short of the minimum requirements of the regulations and regulation whereas the certification from Base Engineering, Inc. appears certainly falls short of the intent of the requirements. issues a DCE must address to satisfy the certification requirements for Please provide FMCSA a clarification which will identify what minimum the passive shutdown system. Thanks for your interest in highway safety. <<>> FEB-12-2002 11:04 AM DJ'S TRUCK REPAIR 618 466 6634 P.01 : D.J.'s Truck Repalr, inc. P.O. I3OX 596-7202 HERTER IND. DR.-GODFREY, IL 62035 (018) 466-9346 .FAX (618) 466-6634 DATE: 2-12-02 SENDOR: LAUE JONES TO/ATIN OF: LANCY SHELTON CO NAME/DEPT: NUMBER OF PAGES INCLUDING COVER PAGE: _.5.. SUBJECT: MR SHELTON I HADE SENT CORY OF BASE AWA NJTS PRODUCTS. PLEASE REUZEW BOrH AWD LET MEKADUI (HANK 1o4 <<>> FEB-12-2002 11:05 AM DJ^S TRUCK REPAIR 618 466 6634 P.82 HAZARDOUS MATERIALS GUIDE $173.515 vahicles in Iiquefied compressed gas service.-(1) Re- (n) Ernergency discharge control for cargo tank motor cargo tank motor vehiole in liquefled oompressed gas quined emergency discharge control equipment. Each gervice must have an omergency dacharge control ca- pability as specified in the following table: 9173.315(n) (1) (* Material (1) Dolivery service Raquired emergenay dis. Diviaion 2.2 materials with no aubsidiary hazard, excluding anhy. All charge control capability (11) drous ammonia. None. Diviaion 2.3 materials. .. All. (ill) Paragraph (n)(2) of thie sec. Division 2.2 materials with a subskilary hazard, Division 2,1 materl- Olher than metered deliv. ton. (lv) als, and anhydrous armonia, ary service. Parograph (n)(2) of this soc. Division 2.2 materlals with a subsldiary hazard, Division 2,1 materi- Metered dellvery service. 13,247.5 L (3,500 water gallons) or leas. als, and anhydrous ammunia in a cargo tank with a capacily of Paragraph (n)(3) of this sec. (v). lion. Division 2.2 materlels with a subsidlary hazard, Division 2.1 materi- er than 13,247.5 L (3,500 water gallons). . Era anydrous armal in cargo tank with a capacity areat. Metered delivery service. paragrapn (n)(3) of this se view deliverles where per- en, and, for obetruct mitted by $177.840(p) of (n) (2) or (n) (4) of this #4c. this subchapter, paragraph delivery servie. A cargo tank motor vehlcle in other than (2) Cargo tank motor vehicles in other than metered tion. off-truck remote means to close the internal self-closing ically shut off the flow of product without the need for hu- metered delivery service must have a means to automat- equipment upon activation by a qualifed person attend- stop valve and shut off all motive and auxiliary power man intervention within 20 seconds of an unintentional ing the unloading of the cargo tank motor vehicle (off- livery hose (passive shut-down capabllity). release caused by a complete separation of a liquid de- tance of 45.72 m (150 feet), The off-truck remote shut-off truck remote shut-off). It must function reliably at a dis- valve is acceptable when authorized by this subchapter. (i) Deaigned flow of product through a bypass in the activalion device must not be capable of reopening the tion. intermal self-closing stop yalve after emergency activa- product flow must be certified by a Design Certifying En- (i) The design for the means to automatically shut off be installed under the supervision of a Registered In- (1) The emergency discharge control equipment must of the original component manufacturer and must explain gineer. The certification must consider any specifications tested to demonstrate that it will close the internal self- spector. Each wireless transmitter/receiver must be how the passive means to shut off the flow of product op- ature, pressure, typas of product) within which the pas- erates. It must also outline the parameters (e.g., temper- closing stop valve and shut off all motive and auxiliary der optimum conditions. Emergency discharge control power equipment at a distance of 91.44 m (300 feet) un- operate. All components of the discharge system that are sive means to shut off the flow of product is designed to recelver must be tested to demonstrate Its functioning at equipment that does not employ a wireless transmitter/ tion. A copy of the design certifcation must be provided integral to the design must be Included in the certifica- the maximum length of the dellvery hose. to the owner of the cargo tank motor vehicle on which the (Il) The Registered Inspector must certify that the re- equipment will be installed. mote control equipment is installed In accordance with slon of a Registered Inspector unless the equipment is (iii) Installation must be performed under the supervi- and is tested in accordance with paragraph (n) (3)(i) of the original component manufecturer's specifications Installed and removed as part of regular operation (e.g., this section. The Registered Inspector muat provide the equipment is installed and tested, if It is possible to do so a hose). The Regiatered Inspector must certify that the owner of the cargo tank motor vehicle with this oertifica- tion. Design Certifying Engineer's certification. The Regis- without damaging the equipment, in accordance with the tem is used to satisfy the requirements of paragraph (4) Query systems. When a transmitter/receiver sys- tered Inspector must provide the certification to the own- (n)(1)(v) of this section, It must close the Internal self- er of the cargo tank motor vehicle. closing stop valve and shut off all mottve and auxiilary service. When required by the table in paragraph (n) (1) (3) Cargo tank motor vehicles in metered delivery the unloading operation prevents it from doing so at least power equipment unless the qualified person attending of this section, a cargo tank motor vehicle must have an be as specifled in paragraph (n) (3) of this section. once every five minutes. Testing and certification must # 800-924-1010 BASK 173-139 11/01 SHAWN OR DAREN STEUE FELIAY <<>> FES-12-2002 11:05 AM DJ^S TRUCK REPAIR HASE EINTINEEZINE 618 466 6634 HASE, P.0s BASE ENCINTERIE UNLE FUEL CONTPOL VICARDO ONES Design Certifying Engineers (DCE) Statemunt for LDS100 Transport Passive Systom dare reginetons 49 Frai a Design Caring Engine ing taci, code of Registration identification number CT-8500. In accordance with United States Department of Transport HM225A requirements, BASE Engineering's "Passive" transport shut dowri systern Engineers. model LDS100 has been designed and tested by registered Design Certifying hose separation and automatically generate a signal to close the tank internal This leak detection system has been tested and verified to delect a complete valve under the following conditions: • A minimum 2" diameter product delivery hose of 20' length is used to offload the tank trailer. • A maximum of B'/2" diameter piping Is used between the pump and hose connection flange. • The pump Is developiny a minimum of 20 PSI differential pressure and pumping liquid product. have not been fully tested as of the dale of this documentation. Conditions outside of the above paramelers may result in correct operation but ..:.: Signed Stephen A. Beiyea 1) President 1:.."v. <<>> FEB 12$2002 11:06 AM DJ'S TRUCK REPAIR 618 466 6634 P. 84 CARSON DIT PRCOURTS 1-4 ENGINEERING PASSEUE SYSTEm Model 400 or Model 500 P.O. Box 2969 • Renton, WA 98056 (206) 235-7551 • FAX (206) 277-5780 • E-MAIL - carengr@nwrain.com PROPANE CARGO TANK UNLOADING SYSTEM CERTIFICATION (A) Янттагу This document in the Design Certilying Engineering certification for the means to design and provide a passiv shutdown far the propane cargo tank (MC330/331 Transporl) unloading system. This syatem shall shut down withi wenty seconds of an unintentional product transler hosa complole separation as requred by the U8 Department o Transportalion regulation in Title 49 CFR 173.315 (n) (2), published on May 24,1900 (64FR28029) The propane cargo tank unloading ayalem consista of a closed process contalning liquid and gassous propane. The Description of the Propano Cargo Tank Unlonding Syslam procees consista of the following components: Component for primary containmen b) A 4-Inch product transfer pump with 2-Inch threaded outlet (Corken Model Z4200 Pump or equivalent) with a A 4-inch flanged Internal vaive attached to the bottom of a cargo tank. c) The combine restriction due to the combination of fittings and pipe shall not exceed an equivalent of 20 differential reilel valve setting not to exceed 100 PSG. IPS pipe, a 2-lnch thread pipe te class 3000 (flow in branch) and a 2-Inch medium sweep sibow class linear feet of 2-inch schedule 80 pipe. Twenty feat of 2-inch pipe le equal to 38-inch long 2-Inch achedule do d) 3000. A 2-Inch full port ball (Isolation) yalve with a flow coefficent of 165 or larger. hose or pipe to the sensing point. On transports with two discharge hose port connections, a three-way A censing paint at discharge end of Item "d" connects to a Line Break Detector with a 'hi" minlmum ID rube vaive selects the sensing polnt on wither the right or the left aide of the cargo tank. 9) A 2-inch male threaded pipe to 3 ¼-inch male ACME adapter h) A 2-inch Claas 3000 threaded coupling A 3 inch female 10 2-inch male threaded pipe adapter A 2-Inch male threaded pipe to 2-Inch crimped ID hose adapter Gomponenta for emergency shutolt valves A 2-inch OD transter hose 40-loat long or lost. 8) b) Spring appled mechanical actuator(s) that automatically close all open product valvez on the cargo tank Line Break Detector (OUT Products ino. Model 400 or 500) C) Emergency Shutalf cables connecting the actuator to Internal valves on cargo tank, i needed. when air pressure is vented from attached mechanical actuator. (C) Certification Carson Engineering (CE) has revlewed lechnical information and equipment specification and performed flow calculations pertalning to normal transfor rates and rates of discharge il a hose were to completaly separato. CE has modeled the equilibrium flow rate during a hose separation (fallure) and has determined that the drop In hose pressure from a normal tranater to fallure conditions is such that the DUT Product Inc.' 1BD Model 400 or 500 can requirements of Title 49 CFR 173.315 (n)(2), It conditions and criterla described below are insured. sanaa and initiate emergency shutolf valve operation. The system described above will meet the design 2) 1) The product transler pump shall not exosed 650-RPM nominal shaft speed. The temperature of the saturated propane is between -20°F and 120°F. 3) the cargo tank will actuate, and the spring to close the actuator Is functional. A visual Inspection of The actuator and cables are in good condition, the cable tansion is such that the internal valves on 4) The tubing connecting the sensing paint and LBD atlachoe between the isolation yelve (tem (f) and the oables and actuator teat is required before transfer la started. ) Properly maintained air eystom free of significent molsture, and properly lubricatec woduct transfer hose with no major obstruction between sensing point and host bove true and correct is a Design Certitying Engingar registered with the U.S. Department of Transportation, I certity thi Signed: D. MADA CARSON - DOT Certification ID #CT8083 STATE PROTE HOTHESE AL <<>> FEB-12-2002 11:07 AM DJ'S TRUCK REPAIR 618 466 6634 P.85 1-5 CARSON DST Products Model 500 only. ENGINEERING PASSIVE SYSTEM F.O. BOX 2969 • Renton, WA 98050 • (206) 235-7651 • FAX (206) 277-5780 • E-MAIL - carengr@nwrain.com ANHYDROUS AMMONIA CARGO TANK UNLOADING SYSTEM CERTIFICATION • (A) This document is the Design Certifying Engineering certication for the maans to design and provide a passive Summary (0) The anhydrous ammonia cargo tank unloading syslem consists of a closed process containing Iquid and gaseous Desoription of the Anhydraus Ammonla Cargo Tank Unloading Systam Component for prlmary contalament anhydrous ammonia. The proceds consisis of the following components: b) A 4-Inch product tranater pump with 2-inch threaded outlet (Corken Modei Z4200 Pump or equivatent) with a A 4-Inch llanged internal valve attached to the bottom of a cargo tank c) The combine restriction due to the combination of fittings and pipe shall not exceed an equivalent of 20 differential relied valva setting not to exceed 100 PSIG. IPS pipe, a 2-inch thread pipe too class 3000 (flow In branch) and « 2-Inch medlum swato olbow class linear feed of 2-Inch schedule 80 pipe. Twenty feal of 2-Inch pipe is equal to 38-Inch lang 2-Inch echedula 80 3000. A sensing point at discharge and of item "d" connecta to a Line Break Detector with & la" minimum iD tube A 2-inch full port ball (laolation) valve with a flow cowlicient of 155 or larger, hose or pipe to the sensing polnt. On transports with two dacharge hose port connections, a three-way A 2-Inch male threaded pipe to 3 'la-inch mala ACME adapter valve selects the sensing point on either the right or the latt side of the cargo tank. 9) A 3'½-Inch female to 2-inch male threaded pipe adapter 1) A 2-inch male threaded pipe to 2-Inch crimped ID hose adapter A 2-inch Class 3000 threaded coupling Semperent for emergency shutot valves A 2-Inch OD transfer hose 40-feet long or loss. b) Line Break Detector (DUT Products Inc. Model 500) Spring applied mechanical actuator(s) that automatically close all open product valves on the cargo tank c) when air pressure is vented from attached mechanical notuator. Emergency Shutoff cables connacting the actuator to internal valves on cargo tank, I needed. (C) Carson Engineering (CE) has reviewed technical information and equipment specialion and performed flow Cartilication calculations pertaining to normal transfer rates and rates of discharge it a hose were to completely separate. CE has pressure from a normal transfer to failure conditions is such that the DUT Product Inc.'s LBD Model 500 can senee modeed the equilibrium flow rate during a hose separation (fallure) and has determined that the drop in hord and Initiate emergency shutoff valve operation. The system deccribed above will meet the design requirements of Title 49 CFR 173.315 (n)(2), It conditions and criteria described below are insured. The temperature of the saturated anhydrous ammonla is between -20°F and 120°F. 3) The actuator and cables are in good condition, the cable tension is such thel the Internal valves on The product transfer pump hall not exceed 850-RPM nominal haft speed. the cargo tank will actuate, and the spring to close the actuator is funciones. A visual inspection of 4) The tubing connecting the sansing point and LBD attaches between the isolation valve (tem o) and the cables and actuator teat la regured before transfer is started. 5) Properly maintalned air system free of significant moisture, and properly lubricated. product transter hose with no major obetruction belwaun sansing polnt and hose. above true and correct. As a Design Certifying Engineer registered with the U.S. Department of Transportation. I •Hy the Signed: 4 CDOT Certification ID #CT8083 PROFESSIO 9/15/0/ ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `ce416a204d3ee1b77fdb701850e11ba50bbfc4451375accd50874e0fd43a76ae` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-22T19:23:11.709Z - Document slug: `phmsa-interpretation-02-0079` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "BASE Engineering, Inc." ], "individuals": [ "William A. 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