TNW_Sole_Source_Final_1.pdf

SOLE SOURCE JUSTIFICATION

Fuel valve and Cap Rotary Seal Procurement

PR 1300655959

Background:

Code 8555 is undergoing an evaluation of the performance of the Fuel Delivery Subsystem related to proper sealing during operational spin. The Rotary Seal (NAVSEA Drawing 6105333) is manufactured from Molybdenum in accordance with ASTM B 387 Type 361 Standard Specification. Within the Fuel Delivery System of the MK 48 Torpedo, the rotary seal functions as half of the dynamic seal between the Fuel Valve and Cap Assembly (FV&C) and the Chamber and Valve Assembly (CVA). The rotary seal is installed inside of the Fuel Valve Assembly (NAVSEA Drawing 6105333) to keep the fuel separate from the coolant and to orientate the rotary seal within the valve. The dynamic sealing surface of the rotary seal must be flat to within three (3) helium light bands (0.0000345”) and have an average surface roughness of 4 micro-inches in accordance with the NAVSEA Drawing 6105333.

The purpose of purchasing rotary seals from Triumph Northwest is to perform an engineering evaluation as part of an ongoing reliability investigation. The evaluation is to determine if the stress-relief technique employed by the manufacturer is superior or equivalent to other stress relief methods. Triumph Northwest uses a stress-relief method that utilizes argon cooling within a vacuum environment.

Requirement:

The manufacturer must meet requirements of the NAVSEA Drawing 6105333. In addition, the manufacturer shall provide data and testing not required to be provided with the normal data package. The manufacturer will not perform functions of NOTE 8. The manufacturer shall supply material certification, penetrant inspection certification, and dimensional inspection.

Sole Source Justification:

Triumph Northwest is the only company that possesses the equipment necessary to manufacture precise dimensions, surface finishes, and stress relief techniques. In the past, vendors have been awarded contracts for the production of these parts and later failed to meet the drawing requirements, due to the specified stress relief methods called out in the drawing.

Triumph Northwest shall produce seventy-five (75) rotary seals that meet the stress relief requirement per Note 3, under vacuum rather than the hydrogen atmosphere requirements.

Triumph Northwest shall produce twenty-five (25) rotary seals that meet the NAVSEA Drawing 6105333 requirements but are not stress-relieved.

RESELLERS:

There are no authorized resellers available.