71588615
Dec 1, 1949
Jan 6, 1953
MAINTENANCE TANKS IN THE FORM OF RELATIVELY DEEP PANS FULLY OPEN AT THE TOP AND PROVIDING A LIQUID HOLDING CHAMBER WITHIN WHICH VISCOUS UNIT TYPE FILTERS ARE CLEANED BY WASHING WITH HOT WATER OR STEAM AND THEN RECHARGED WITH A COATING OF A DUST CATCHING LIQUID BY IMMERSION THEREIN
Paints