USDA, ARS, North Atlantic Area, Contracting Office, 600 East Mermaid Lane, Wyndmoor, PA 19038

43 -- TWO-STAGE, LIQUID-RING VACUUM PUMP SOL 23-3615-99 DUE 072099 POC Lisa M. Botella, Contracting Officer and Point of Contact, (215) 233-6551, fax (215) 233-6558 This requirement was initially synopsized on July 6, 1999 and is amended to include responses to the following questions: Answers to questions received in response to the subject solicitation. It is Understood: Vacuum pump system will be operational on flatbed truck w/other vacuum system auxiliaries (supplied by other). QUESTION: Will there be a self-contained chill water system maintained on flatbed truck? ANSWER: Yes, the Government shall provide the chilled water system when necessary. QUESTION: Will "Glycol-water, methanol" solutions be used as pump sealant or as chill fluid? ANSWER: Either glycol-water or methanol solutions will be used as required to achieve the desired vacuum for the pump sealant and either solution will be used as the chill fluid. Per specification A.8.1, seal liquid may be water for a vacuum of 30 Torr. Chiller (HEX) fluid may be water too for those conditions. Lower temp sealing liquids will be used for higher vacuum. At lower temperatures, it is likely that the sealant will be the glycol or methanol solutions. The HEX fluid would then also be a glycol or methanol solution. There may be some operating conditions where the sealant is water, but it is advantageous to use methanol or glycol solution for the HEX. QUESTION: Will "13 Fahrenheit" will be the temperature of the sealant or the chill system? ANSWER: The temperature listed in A.8.3 is for the sealant. QUESTION: The chill system fluid will consist of what type fluid, supplied at what flow rate, supplied at what temperature? ANSWER: For the purpose of sizing the HEX, the chill fluid is house water at 40psig. The conditions under which the capacity requirement to be met are stated in Section A.8.1. The high vacuum conditions utilizing other chill fluids are likely to be at a reduced capacity which need not be quantified at this time. Understood: "up to 4.5 pounds per minute of water" will enter the seal liquid system and accumulate in the seal liquid full recovery tank. QUESTION: Will then the seal liquid by H2O, or if "glycol-water, methanol," inform us on how you will deal with seal liquid dilution? ANSWER: The seal liquid is addressed above. If glycol or other solution is used, dilution will be addressed either by limiting the length of the experiment based on seal liquid freeze point or by addition of glycol, etc. This addition, if required will be installed by the Government. QUESTION: How do you intend to accommodate for water accumulation in the seal liquid full recovery tank? ANSWER: Section A.8.3 defines the recycle circuit. Excess seal liquid will be overflowed to drain or to a collection tank as appropriate to the sealing fluid in use. QUESTION: Are you requiring automatic or manual auxiliaries? ANSWER: No automatic controls for liquid level are required. 2) THE HOUR AND DATE SPECIFIED FOR RECEIPT OF OFFERS IS UNCHANGED AND REMAINS 4:30 P.M. (LOCAL TIME) ON JULY 20, 1999. All other information in the initial synopsis remains unchanged. Posted 07/09/99 (W-SN352551). (0190)

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