SATPC0041250 Tab 04 4 SOW.pdf

Statement of Work for Procurement of Pressurized Liquid Nitrogen Dewars

1.0 Introduction/Background:

The Advanced Materials and Processing Branch relies extensively on pressurized liquid nitrogen (LN2) dewars to support a myriad of mission-relevant laboratory operations, material testing, and characterization efforts. Currently, the branch utilizes dewars that are many years old. Because these vessels are subjected to extreme thermal cycling and sustained pressure, replacing this aging equipment is a critical, proactive measure to prevent unanticipated safety failures. Upgrading these essential supplies will ensure uninterrupted laboratory operations while maximizing the safety of personnel handling hazardous cryogenic materials.

2.0 Scope of Work:

The scope of this Statement of Work (SOW) covers the procurement and delivery of five

(5) 230-liter (230 L) pressurized liquid cylinders (dewars) specifically designed for liquid nitrogen storage and handling. The replacement dewars must meet or exceed all current industry safety standards for the handling of liquid nitrogen from a pressurized system.

The scope requires that the procured units are fully capable of safely executing all standard laboratory cryogenic activities, including filling the vessel from a completely empty, ambient-temperature state (a "hot tank") and safely dispersing liquid nitrogen into both secondary pressurized vessels and unpressurized open containers.

3.0 Objectives:

The primary objective of this procurement is to safely modernize the cryogenic storage capabilities of the Advanced Materials and Processing Branch by successfully replacing the current aging 230 L pressurized dewars. Procuring this new equipment will proactively eliminate the safety risks associated with operating degraded pressure vessels, specifically mitigating the hazards of unanticipated structural failure, exposure to extreme cryogenic temperatures, and the release of potentially asphyxiating gases in the laboratory environment.

4.0 Description of the Work/Contractor Tasks:

The Contractor shall supply and deliver the required laboratory equipment (five 230 L pressurized liquid nitrogen dewars) to the National Aeronautics and Space Administration (NASA). This procurement must be executed in a manner consistent with responsible fiscal practices, ensuring the Government receives optimal value without compromising on the critical safety components required for cryogenic pressure vessels.

The Contractor shall perform the following tasks:

• Supply five (5) new, defect-free 230 L pressurized liquid cylinders that strictly conform to the specifications outlined in Section 5.0.

• Ensure all supplied equipment fully complies with national pressure vessel and cryogenic safety standards.

• Coordinate the timely and secure delivery of the dewars to the designated NASA facility, ensuring that the structural integrity and high-level safety features of the supplies are maintained during transit.

5.0 Deliverables:

Execution of this procurement request shall result in the delivery of five (5) 230 L liquid nitrogen dewars. The Contractor shall ensure that all five deliverables meet the following mandatory specifications, material properties, and safety criteria:

General & Structural Requirements:

• Designed as a premium, transportable liquid cylinder strictly for cryogenic service.

• Constructed of high-quality stainless steel.

• Equipped with a thick, dent-resistant outer shell to withstand laboratory environments.

• Engineered with a robust inner-vessel support system.

• Features a base design consisting of a round bottom equipped with durable, load-bearing casters for safe mobility.

• Features a large-diameter handling ring secured with a minimum of four structural supports.

• All fixtures, seals, and connections must be specifically rated and appropriate for use with nitrogen gas and liquid nitrogen.

Valves, Instrumentation, and Safety Features:

• Pressure Builder (PB) Valve/Regulator: Must control the internal circuit that converts liquid to gas to effectively increase pressure for dispensing.

• Liquid Valve & Port: Must provide a secure outlet to dispense liquid nitrogen.

• Gas Use Valve: Must allow for the safe withdrawal of nitrogen in its gaseous form.

• Pressure Gauge: Must provide an accurate, easy-to-read display of internal vessel pressure.

• Liquid Level Gauge: Must accurately measure and display the amount of remaining liquid nitrogen.

• Vent Valve: Must allow for manual venting of gas to safely reduce internal pressure when required.

• Pressure Relief Valve (PRV): Must be calibrated to release excess pressure automatically to prevent over-pressurization and catastrophic failure.

• Rupture Disk: Must be installed as a secondary, fail-safe backup that automatically ruptures to depressurize the tank in the event of PRV failure.

• Transfer Hose: Must include a specially insulated, vacuum-jacketed hose rated for the safe transfer of cryogenic liquids.