the means being helically-wound fins or wire spirals

Full Title

Tubular elements; Assemblies of tubular elements > Tubular elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses > the means being only outside the tubular element > and extending obliquely > the means being helically-wound fins or wire spirals

Classification Context

Section:

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

Class:

HEAT EXCHANGE IN GENERAL

Subclass:

DETAILS OF HEAT-EXCHANGE OR HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION