TANKCON — Hazardous Materials Safety Interpretation

Page 1of Transportation U.S.Department 400 Seventh Street. S.W Special Programs Research and Washington, D.C. 20590 Administration MAY 8 1998 Mr. Al Chatillon, P. Eng. TANKCON 4250 Marcel Lacasse, Boisbriand, Que. J7H 1N3 Dear Mr. Chatillon: This is in response to your letter concerning the location of pressure relief devices specified in 49 CFR 178.345-10(c). You state that your understanding is that a cargo tank designed with all inlets/outlets in the rear, but with the pressure relief vent in the top of the manhole cover, would comply with § 178.345-10(c) even if the vent is not in the center of the tank. Section 178.345-10(c) provides specific requirements for the location of relief devices and several examples on where relief can be located. It states "Each pressure relief device must communicate with the vapor space above the lading as near as practicable to the center of the vapor space." This requirement applies regardless of vehicle orientation. Therefore, the configuration you suggest would not meet the requirements of the Hazardous Materials Regulations unless the manhole cover is located as near practicable to the center of the vapor space. If you need further assistance, please contact us. Sincerely, Thorns I. Allan Thomas G. Allan Senior Transportation Regulations Specialists Office of Hazardous Materials Standards#

Page 202/24/98 18:32 84376208 TANKCONFRP Ø001 Kaim STANKCON File 178.345-10 DAp' ebruary 24th, 1998 -fice of Hazardous Materials 5. Department of Transport Standards ashington, DC. 1590 *ention: Mr. E. Mazzulla, Interpretation of 178.345-10 c) Location of relief devices lowing my conversation with Mr. P. Olsen concerning an erstanding, could please confirm this position. erpretation of Section 178.345-10 c) you will find here in our • 're of the tank. ser section 178.345-10 c) the pressure relief device must be :ontact with the vapor. space and as close as practible to top i stion: If the tank is designed with all the inlets/outlets in the rear and the vent is located in the top of the contact with location would comply with section 178.345-10 c) even the vapor space and consequently this if it is not located in the centre of the tank. files. agree with the above statement? If so please confirm for WE -ank you in advance for your cooperation. Ya Truly, A1 - in ita Chatillon, F.Eng. • :T. 4250 arcel Locasse, Boisbriand, Qué. J7H 1N3 • Tél: (514) 435-5483 • Fox: (514) 437-6208 4:.#