Cellulose-sponge disk absorbs incoming water and expands with enough force to shut valve. When water recedes, valve opens by squeezing sponge dry to its original size. This direct mechanical action is considered more reliable than solenoid valve.
Automatic shutoff valve
NASA Tech Briefs ; 5 , 1
1980-08-01
Miscellaneous
No indication
English
NTRS | 1992
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