Patent Number: 6,308,720

Title: Method for precision-cleaning propellant tanks

Abstract: A method for precision-cleaning the aluminum alloy inner wall surface of atank is disclosed. In one embodiment, the inner wall surface is cleaned bya method including the steps of washing the inner wall surface with afirst portion of water, applying an aqueous cleaning solution comprisingsodium silicate, sodium tetrafluoroborate and sodium molybdate, andrinsing the inner wall surface with a second portion of water. In a secondembodiment, the method is directed to precision-cleaning a launch vehiclebooster propellant tank. In this embodiment, the method includes the stepsof applying washes of water and aqueous cleaning solution on at leastupper and lower sections of the inner wall surface of the tank, washingsuch sections with water, and analyzing samples of effluent cleaningsolution and water collected from the effluent drain of the tank forhydrocarbon and particulate contaminants. In a third embodiment, themethod further includes drying the tank and verification of hydrocarbonsand nonvolatile residues and then further drying the tank to the systemlevel requirement.

Inventors: Modi; Paresh R. (Highlands Ranch, CO)


International Classification:

Expiration Date: 10/32013