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Precision Cleaning Verification of Fluid Components by Air/Water Impingement and Total Carbon AnalysisNASA personnel at Kennedy Space Center's Material Science Laboratory have developed new environmentally sound precision cleaning and verification techniques for systems and components found at the center. This technology is required to replace existing methods traditionally employing CFC-113. The new patent-pending technique of precision cleaning verification is for large components of cryogenic fluid systems. These are stainless steel, sand cast valve bodies with internal surface areas ranging from 0.2 to 0.9 m(exp 2). Extrapolation of this technique to components of even larger sizes (by orders of magnitude) is planned. Currently, the verification process is completely manual. In the new technique, a high velocity, low volume water stream impacts the part to be verified. This process is referred to as Breathing Air/Water Impingement and forms the basis for the Impingement Verification System (IVS). The system is unique in that a gas stream is used to accelerate the water droplets to high speeds. Water is injected into the gas stream in a small, continuous amount. The air/water mixture is then passed through a converging-diverging nozzle where the gas is accelerated to supersonic velocities. These droplets impart sufficient energy to the precision cleaned surface to place non-volatile residue (NVR) contaminants into suspension in the water. The sample water is collected and its NVR level is determined by total organic carbon (TOC) analysis at 880 C. The TOC, in ppm carbon, is used to establish the NVR level. A correlation between the present gravimetric CFC-113 NVR and the IVS NVR is found from experimental sensitivity factors measured for various contaminants. The sensitivity has the units of ppm of carbon per mg-ft(exp 2) of contaminant. In this paper, the equipment is described and data are presented showing the development of the sensitivity factors from a test set including four NVR's impinged from witness plates of 0.05 to 0.75 m(exp 2).
Document ID
19970020256
Acquisition Source
Kennedy Space Center
Document Type
Conference Paper
Authors
Barile, Ronald G.
(I-NET, Inc. Cocoa Beach, FL United States)
Fogarty, Chris
(I-NET, Inc. Cocoa Beach, FL United States)
Cantrell, Chris
(I-NET, Inc. Cocoa Beach, FL United States)
Melton, Gregory S.
(NASA Kennedy Space Center Cocoa Beach, FL United States)
Date Acquired
August 17, 2013
Publication Date
July 1, 1995
Publication Information
Publication: Environmentally Sound Processing Technology: JANNAF Safety and Environmental Protection Subcommittee and Propellant Development and Characterization Subcommittee Joint Workshop
Subject Category
Environment Pollution
Accession Number
97N21700
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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