Our compression couplings get their leak-proof seal by a simple but clever design which involves an inner and an outer shell. When the bolts are tightened, the outer shell is drawn firmly against the inner shell. They are available in galvanised or stainless (Code suffix SS). The food quality units have white neoprene, sanitary liners. Designed for low pressure pneumatic conveying systems less than 1 bar pressure. There are fifteen sizes from 38 to 355mm tube, beginning with the suffix CC-then insert Outside Diameter in mm.