[Code of Federal Regulations] [Title 46, Volume 1] [Revised as of January 1, 2007] From the U.S. Government Printing Office via GPO Access [CITE: 46CFR39.40-3] [Page 516] TITLE 46--SHIPPING CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PART 39_VAPOR CONTROL SYSTEMS--Table of Contents Subpart 39.40_Lightering and Topping-Off Operations with Vapor Balancing Sec. 39.40-3 Design and equipment for vapor balancing--TB/ALL. (a) If the cargo tanks on a vessel discharging cargo and a vessel receiving cargo are inerted, the service vessel must: (1) Have a means to inert the vapor transfer hose prior to transferring cargo vapor; and (2) Have an oxygen analyzer with a sensor or sampling connection fitted within 3 meters (9.74 ft.) of the vessel vapor connection which: (i) Activates an audible and visible alarm at a location on the service vessel where cargo transfer is controlled when the oxygen content in the vapor collection system exceeds 8 percent by volume; (ii) Has an oxygen concentration indicator located on the service vessel where the cargo transfer is controlled; and (iii) Has a connection for injecting a span gas of known concentration for calibration and testing of the oxygen analyzer. (b) If the cargo tanks on a vessel discharging cargo are not inerted, the vapor collection line on the service vessel must be fitted with a detonation arrester that meets the requirements of 33 CFR 154.822(a) located within 3 meters (9.74 ft.) of the vessel vapor connection. (c) An electrical insulating flange or one length of non-conductive hose must be provided between the vessel vapor connection on the service vessel and the vapor connection on the vessel being lightered or topped- off.