AN ENHANCED SURFACE TUBE

摘要

An enhanced surface tube is made up of at least two conduits with the inner conduit (2) being stainless steel and with a spiral groove (4) extending in from the outer surface of the twin wall tube and forming a radially inwardly extending spiral protuberance (5) on the inner surface of the stainless steel conduit thus interconnecting the two conduits so that in use they will act as a single enhanced surface tube.