Pneumatic Impact Ignition of Sebum Oil Film in High-Pressure Oxygen

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Volume 3, Issue 8 (September 2006)

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ISSN: 1546-962X
Page Count: 10

Pneumatic Impact Ignition of Sebum Oil Film in High-Pressure Oxygen
Tapia, SA
Project Leader, NASA Johnson Space Center White Sands Test Facility, New Mexico

Smith, SR
Mechanical Engineer, Honeywell Technology Solutions Inc., NASA Johnson Space Center White Sands Test Facility, New Mexico

Hshieh, F-Y
Materials and Combustion Scientist, Honeywell Technology Solutions Inc., NASA Johnson Space Center White Sands Test Facility, New Mexico

Stoltzfus, JM
Project Manager, NASA Johnson Space Center White Sands Test Facility, New Mexico

(Received 21 October 2005; accepted 16 May 2006)

Abstract

Whenever oxygen systems are assembled or maintained, a risk of introducing contamination arises. Potential contaminants include oils from a person's hands and body left behind in the form of fingerprints. The oil on the surface of skin is a complex mixture of sebum oil, lipids, sweat, and environmental materials. In high-pressure systems, heat from rapid pressurization is a high-risk ignition mechanism for the sebum contaminant. The rapid pressurization or pneumatic impact ignition of hydrocarbon-based oil contaminant in high-pressure oxygen has been widely studied. This study investigated the rapid pressurization ignition of sebum contaminant in high-pressure oxygen. The pneumatic impact ignition test of sebum contaminant was conducted according to NASA-STD-6001 Test 14. The ends of stainless steel cylindrical rods were coated with synthetic sebum at varying surface concentrations, and impacted with 27.6 MPa oxygen. The results show that there is a threshold level of sebum contaminant for ignition by rapid pressurization. The level of sebum contaminant that can be expected to be deposited by handling oxygen system components, an analysis on sebum oil properties and associated fire hazards, and the threshold levels of sebum contaminant required for rapid pressurization ignition in a high-pressure oxygen system are presented and discussed.

Keywords:
pneumatic impact, rapid pressurization ignition, sebum contaminant, adiabatic compression, high-pressure oxygen, ignition threshold, ignition probability

Paper ID: JAI13679
DOI: 10.1520/JAI13679
ASTM International is a member of CrossRef.

Author Title Pneumatic Impact Ignition of Sebum Oil Film in High-Pressure Oxygen Symposium Flammability and Sensitivity of Materials in Oxygen-Enriched Atmospheres, 2006-10-20 Committee G04

		Home Journals STPs Manuals Topics Subscriptions/Pricing Digital Library / Journals / Journal of ASTM International (JAI) / Citation Page Volume 3, Issue 8 (September 2006) Click here to download this paper now for $25 PDF (208K) View License Agreement ISSN: 1546-962X Page Count: 10 Pneumatic Impact Ignition of Sebum Oil Film in High-Pressure Oxygen Tapia, SA Project Leader, NASA Johnson Space Center White Sands Test Facility, New Mexico Smith, SR Mechanical Engineer, Honeywell Technology Solutions Inc., NASA Johnson Space Center White Sands Test Facility, New Mexico Hshieh, F-Y Materials and Combustion Scientist, Honeywell Technology Solutions Inc., NASA Johnson Space Center White Sands Test Facility, New Mexico Stoltzfus, JM Project Manager, NASA Johnson Space Center White Sands Test Facility, New Mexico (Received 21 October 2005; accepted 16 May 2006) Abstract Whenever oxygen systems are assembled or maintained, a risk of introducing contamination arises. Potential contaminants include oils from a person's hands and body left behind in the form of fingerprints. The oil on the surface of skin is a complex mixture of sebum oil, lipids, sweat, and environmental materials. In high-pressure systems, heat from rapid pressurization is a high-risk ignition mechanism for the sebum contaminant. The rapid pressurization or pneumatic impact ignition of hydrocarbon-based oil contaminant in high-pressure oxygen has been widely studied. This study investigated the rapid pressurization ignition of sebum contaminant in high-pressure oxygen. The pneumatic impact ignition test of sebum contaminant was conducted according to NASA-STD-6001 Test 14. The ends of stainless steel cylindrical rods were coated with synthetic sebum at varying surface concentrations, and impacted with 27.6 MPa oxygen. The results show that there is a threshold level of sebum contaminant for ignition by rapid pressurization. The level of sebum contaminant that can be expected to be deposited by handling oxygen system components, an analysis on sebum oil properties and associated fire hazards, and the threshold levels of sebum contaminant required for rapid pressurization ignition in a high-pressure oxygen system are presented and discussed. Keywords: pneumatic impact, rapid pressurization ignition, sebum contaminant, adiabatic compression, high-pressure oxygen, ignition threshold, ignition probability Paper ID: JAI13679 DOI: 10.1520/JAI13679 ASTM International is a member of CrossRef. Author Title Pneumatic Impact Ignition of Sebum Oil Film in High-Pressure Oxygen Symposium Flammability and Sensitivity of Materials in Oxygen-Enriched Atmospheres, 2006-10-20 Committee G04