دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a volcanic rock that can be extended to many times its original volume by crushing and heating under pressure. Release of the pressure causes expansion when the water in the rock turns to steam. It is used as an extender in cement.

n: generally speaking, it refers to some different size of product that made of pearl rock. it uses as porous loss layer block agent.