Stepped double-L fin strip helically wound so each fin overlaps the foot of the next — complete base-tube coverage for superior corrosion protection at a lower cost than extruded fin.
LL-Foot, or overlapped L, fintube is fabricated from strip formed into a stepped double-L shape, then rolled into a taper that causes it to curl. That profile is continuously helically wound under tension onto the tube so that one fin overlaps the foot of the next, achieving complete coverage of the base tube surface beneath the fin.
That continuous overlap provides good corrosion protection to the tube, making LL-Foot fin an effective alternative to the more expensive extruded fin type in corrosive environments — without leaving any bare tube exposed between fins.
A tapered, overlapping fin profile built for complete tube coverage.
Fin strip is formed into the stepped double-L profile.
The strip is rolled into a taper that causes it to curl into its final shape.
The tapered strip is wound helically onto the tube under controlled tension.
Each fin overlaps the foot of the previous fin, fully covering the base tube.
Fin height, pitch, and overlap coverage are verified against specification.
Tapered-strip forming and winding hardware for full tube coverage.
Forms the stepped double-L profile on the fin strip stock.
Rolls the strip into the taper that produces the characteristic curl.
Winds the tapered fin strip helically onto the tube.
Ensures each fin foot fully overlaps the foot of the previous fin.
Verifies fin height, pitch, and coverage against specification.
Prepares finished tube for coiled or cut-to-length delivery.
Complete tube coverage for service where corrosion protection is critical.
Cost-effective corrosion-resistant finning for upstream and midstream service.
An economical alternative to extruded fin in aggressive process environments.