The SPIR160 is a 160mm diameter, 3-metre length of galvanised spiral ducting, manufactured from spiral-wound galvanised mild steel to HVCA/BESA DW144 specification. It forms the core straight-run component of a 160mm metal ducting system, suitable for general ventilation, mechanical extract, MVHR distribution, dust extraction, and fume control. The hot-dip galvanised (Sendzimir) zinc coating provides long-term corrosion resistance without painting, and the smooth-bore interior keeps airflow resistance low along the run.
Female Tube System: Spiral duct of this type is manufactured female at both ends — all bends, tees, and reducers in the matching 160mm range are male and slip directly inside the tube. To join two lengths of SPIR160 tube together, use the SPIRC160 male connector.
Handling — Sharp Edges: Cut and formed galvanised steel edges can be sharp. Wear cut-resistant gloves when handling, cutting, or installing spiral duct sections, and deburr any field-cut ends before assembly.
Key Features
Galvanised Steel to DW144
Manufactured to the HVCA/BESA DW144 specification for sheet metal ductwork — the recognised UK standard for spiral ductwork construction and performance.
Z275 Hot-Dip Zinc Coating
The Sendzimir hot-dip galvanising process applies a 275g/m² zinc coating, giving the duct strong corrosion resistance for long-term indoor and protected outdoor use without painting.
Smooth Internal Bore
The spiral-wound construction produces a duct that is almost smooth on the inside, minimising turbulence and airflow resistance compared to flat-seamed ducting.
Female-Ended Tube
Both ends of the 3m length are female, accepting the male spigots of bends, tees, reducers, and connectors from the matching 160mm spiral range.
Inherent Rigidity & Strength
The spiral seam construction gives the tube greater stiffness for a given gauge than equivalent longitudinal-seam ducting, helping the duct hold its shape under handling and installation.
Wide Application Range
Suitable for general ventilation, MVHR/MEV distribution, dust extraction, fume extraction, and air conditioning ductwork in domestic, commercial, and light industrial settings.
Specifications
| Reference |
SPIR160 |
| Diameter |
160 mm |
| Length |
3,000 mm (3 m) |
| Material |
Galvanised mild steel — spiral-wound |
| Manufacturing Standard |
HVCA / BESA DW144 |
| Zinc Coating |
Z275 (275 g/m²), Sendzimir hot-dip galvanised |
| End Configuration |
Female both ends |
| Max Continuous Operating Temperature |
~70°C |
| Typical Applications |
Ventilation, MVHR/MEV runs, dust & fume extraction, air conditioning |
Frequently Asked Questions
How do I join two SPIR160 lengths together?
Use a SPIRC160 male connector. Since both ends of the tube are female, the male connector slides inside the female ends of the two adjoining lengths to create the joint.
Can I cut the tube to a shorter length on site?
Yes — spiral duct can be cut with a jigsaw, angle grinder with a metal cutting disc, or tin snips for thinner gauges. Deburr the cut edge thoroughly, as cutting removes the factory-formed female end and a connector will be needed at that end to mate with a fitting.
Is this duct airtight straight out of the box?
The spiral-formed seam gives a good base level of airtightness, but for higher airtightness classes (Class C/D to EN 12237), joints should be sealed with an appropriate duct sealant or aluminium foil tape in addition to mechanical fixing (rivets or self-drilling screws).
Can this duct be used outdoors?
The Z275 galvanised coating provides good corrosion resistance, making the duct suitable for covered or sheltered external runs. For fully exposed long-term outdoor installations, consider additional weather protection or a higher-spec coating.
What gauge is the SPIR160 manufactured to?
Standard galvanised spiral duct in the 160mm size range is manufactured to DW144 gauge requirements for that diameter — typically 0.6mm for 160mm. Refer to your supplier's DW144 gauge table for the exact specification at this diameter.
