National Stock Number
4320-00-604-1991
National Stock Number (NSN) 4320-00-604-1991, or NIIN 006041991, (ring,wearing) was assigned January 1, 1963 in the Federal Logistics Information System (FLIS). This NSN does not replace any other NSNs.
There are 2 manufacturer part numbers associated with this NSN. One of those part number(s) are considered obsolete. The manufacturer part numbers were originally supplied by one supplier. Today, one supplier is listed as an Active supplier for this NSN. Of the active suppliers, only one supplier is deemed design controlled or valid supply parts.
This part number has not been procured by the US Government in over 5 years.
Based on a planned procurement review by the Primary Inventory Control Activity (PICA) on Sep 20, 2008, this NSN's acquisition method was noted as: Acquire directly from the actual manufacturer, whether or not the prime contractor is the actual manufacturer. The annual buy value of this part falls below the screening threshold of $10,000 but it has been screened for known source(s). (NOTE: This code shall not be used when screening parts entering the inventory. It shall not be assigned in preference to or supersede any other AMSC.) Valid AMCs: 1, 2, 3, 4 and 5.
This NSN is assigned to Item Name Code (INC) 22534. [A CYLINDRICAL ITEM WITH OR WITHOUT FLANGE(S), DESIGNED TO BE INSERTED IN A PUMP CASING OR SECURED TO THE IMPELLER OF A CENTRIFUGAL PUMP. IT IS USED FOR THE PURPOSE OF PROVIDING A CLOSE RUNNING CLEARANCE BETWEEN THE IMPELLER AND CASING IN ORDER TO PREVENT OR OVERCOME LEAKAGE DUE TO EROSION. IT MAY ALSO BE USED AS A DIFFUSER RING IN THE SUCTION AND DISCHARGE THROATS OF VALVES.]. This item does not have a nuclear hardened feature or any other critical feature such as tolerance, fit restriction or application. There is no data in the HMIRS and the NSN is in an FSC not generally suspected of containing hazardous materials. NSN 4320006041991 contains an unknown precious metal.
This information was last updated on Aug 01, 2025.