Centers for Disease Control and Prevention (CDC), Procurement & Grants Office, 255 East Paces Ferry Road, N.E., Room No. 419 Atlanta, Georgia 30305

41 -- CRYOGENIC STORAGE DEWARS (LIQUID NITROGEN FREEZERS - 20 EACH) SOL 95-185(N) DUE 083195 POC Contact Leonard W. Sandberg at (404)842-6553 Cryogenic Storage Dewars (Liquid Nitrogen Freezers - 20 Each): The Cryogenic Storage Dewars are part of a liquid nitrogen system that is designed to store and provide low pressure liquid nitrogen to cryogenic storage dewars (freezers) located in the CDC Serum Bank, Building C, Lawrenceville, Georgia. Dewars that meet the technical requirements of this specification will readily interface with the CDC's standard dewar alarm system. The system is designed to be modular in construction so that it can be easily expanded inside the facility. The system consist of, but is not limited to, the following: CRYOGENIC MATERIALS: The equipment that is provided under this specification must be manufactured for use with extremely low temperatures (-196 degrees C). Any material coming in contact with liquid nitrogen should be either stainless steel, Invar, brass, bronze, copper, aluminum, Teflon, or Kel-F. Any material coming in contact with cold nitrogen vapors should be appropriate for low temperatures. STANDARDS: The equipment to be provided should be manufactured to the appropriate designs, specifications, procedures and inspection requirements as developed by the equipment manufacturer. PRODUCT REQUIREMENTS: The Cryogenic storage dewars (freezers) shall be designed for the long term storage of biological samples through cryogenic refrigeration. It shall be a self contained system that can automatically fill liquid nitrogen at low pressures. It shall display the inside temperature of the freezer in degrees Centigrade. The system shall have a built-in alarm that can indicate to a central alarm system when a malfunction in filling or high temperature has occurred. The dewar shall be cylindrical and shall be no greater than 1067mm in diameter. The internal diameter shall be a minimum of 990mm and the useable height shall be a minimum of 680mm. The dewar shall have an evaporation rate not to exceed 10 liters per day in liquid nitrogen. The dewar should be provided from a manufacturer that specializes in the design and manufacturing of cryogenic storage dewars. PRODUCT DESCRIPTION: The freezer is comprised of the Cryogenic Dewar, the Automatic Filling System, the Display Panel and the Sensor and Alarm System. (A) The Cryogenic Dewar is the mechanical portion of the freezer assembly. It is a double walled, vacuum/super insulated cryogenic vessel. It should be designed for atmospheric pressure and should have an open top that is closed with a cork style lid. The inside lid construction shall be of a foam material that offers the best possible insulation while being durable enough to undergo opening and closing of the lid. A plastic covering of the foam cork is not allowed. The lid shall be hinged and balanced for easy opening and closing. The lid must have a built-in lock with a unique key sequence (such that no two freezers are keyed alike). Two keys for each freezer shall be provided. The freezer shall have casters on the base that allow easy movement of the system. (B) The Automatic Filling System for the freezer shall be designed to sense a low liquid level and fill the cryogenic dewar until the liquid reaches a high liquid level. The level points must be adjustable. The filling system shall have provisions to over-ride the automatic system and fill the unit manually. The system shall have a relief valve installed between the fill valve and the fill hose connection. (C) The Temperature Probe shall be adjustable so that it can be set to read the temperature at various levels inside the cryogenic dewar. (D) The Freezer Display Panel shall indicate the normal operating and alarm conditions of the storage dewar. Solicitation 94-185(N) will be available on or about August 1, 1995. Only written requests for the solicitation package will be honored. (0194)

Loren Data Corp. http://www.ld.com (SYN# 0465 19950714\41-0001.SOL)