receive the vapors 12 exiting detector 32 and to direct the vapors 12 to a vapor handling device described below to prevent the vessel 10 from collapsing care must be taken to prevent the blower 34 from creating an excessive vacuum within the vessel 10 the vapors 12 may be directed by the blower 34 through a filter 36 for extracting condensed liquids from the vapors 12 flowing through the recovery line 28 after passing through the filter 36 the vapors 12 may be passed to a vapor handling device 38 where the vapors 12 are processed for further handling preferably the vapors are combusted and destroyed prior to their emission to the atmosphere if the combustibility of the vapors 12 is insufficient for adequate burning a supply of natural gas propane butane or other high btu source material may be provided under the control of a valve to increase the btu level of the vapors 12 alternatively the vapors 12 can be condensed or cooled to a liquid form by a refrigeration system the recovered liquids can be deposited in a storage tank for further handling the vapors 12 can also be sent to a system in which the vapors 12 are compressed and refrigerated for further handling another possibility is that the vapors 12 can be passed through a molecular sieve material that absorbs hydrocarbons those of ordinary skill in.