3M™ Glass Bubbles S38 have a density of 0.38 g/cc and an isostatic crush strength of 4000 psi. The S Series glass bubbles have smaller particle sizes than the K Series.
The low thermal conductivity of 3M's38 glass bubbles makes them ideal additives in insulation for pipelines and production risers helping to ensure that hot oil continues to flow to the surface, rather than cooling and slowing. High strength (rated to 4000 psi) means they can survive both the rigorous demands of processing and the enormous water pressure at depth. Like all 3M glass bubbles, S38 glass bubbles are virtually insoluble in water or oil.