160mm to 150mm Reducer Galvanised Spiral Duct

Description

The VEL12/0016 is a 160mm to 150mm concentric reducer for galvanised spiral ducting, providing a one-piece transition between 160mm and 150mm duct diameters within a metal spiral system. Manufactured from lightweight galvanised steel to DW144 specification, the reducer is a male fitting that fits directly into the female end of 160mm spiral duct, with the 150mm end sized for connection to 150mm ductwork, fan spigots, or terminal fittings.

160mm

Inlet Diameter

150mm

Outlet Diameter

Concentric

Reducer Type

Male

Fitting Type

Galvanised Steel

Material

Concentric Reducer: A concentric reducer steps the duct diameter down (or up) on the same centreline, giving a smooth, symmetric transition that helps maintain even airflow distribution across the duct cross-section.

Joining Two Male Fittings: Like other spiral fittings, the VEL12/0016 is male. If it needs to connect to another male fitting (e.g. directly to a 150mm bend), a female connector will be required at that joint — it will not fit directly into another male spigot.

Key Features

160mm to 150mm Transition

Provides the standard one-piece reduction between 160mm and 150mm spiral duct diameters — used wherever a 160mm main run needs to step down to a 150mm branch, fan spigot, or terminal.

Concentric Profile

The concentric (on-centre) taper provides a smooth, symmetric transition that helps maintain even velocity distribution through the reduction, compared to an offset (eccentric) reducer.

Galvanised Steel to DW144

Manufactured from lightweight galvanised steel to HVCA/BESA DW144 specification, consistent with the rest of the 160mm spiral range.

Male Fitting — Fits Inside 160mm Duct

The 160mm end is male and slips directly into the female end of a SPIR160 duct length, with the 150mm end sized to suit the connecting 150mm component.

Fan & Terminal Adapting

Commonly used to adapt a 160mm spiral main run to a fan, valve, or grille with a 150mm connection, avoiding the need for improvised or taped reductions.

Compact Single-Piece Body

The reducer is a single pressed component, keeping the transition compact and straightforward to fit within ceiling voids and service routes.

Specifications

Reference	VEL12/0016
Inlet Diameter	160 mm
Outlet Diameter	150 mm
Type	Concentric reducer
End Configuration	Male — fits inside 160mm female duct end
Material	Galvanised mild steel
Manufacturing Standard	HVCA / BESA DW144
Use With	SPIR160 (160mm side) and 150mm ductwork/fittings (150mm side)

Frequently Asked Questions

Can this reducer be used in reverse, to step up from 150mm to 160mm?

A concentric reducer can physically be installed in either direction, but it is designed primarily as a step-down (160mm to 150mm) fitting. If stepping up, check that the 150mm end correctly engages with your 150mm ductwork before fixing.

Will reducing from 160mm to 150mm affect airflow?

Reducing duct diameter increases air velocity and adds resistance at that point in the system. Ensure your fan or MVHR unit can deliver the required flow rate against the additional pressure drop introduced by the reduction.

How does the 160mm end connect to the spiral duct?

The 160mm end of the VEL12/0016 is male and inserts directly into the female end of a SPIR160 duct length, secured with self-drilling screws or rivets and sealed as required.

What if I need to connect the 150mm end to another fitting rather than a duct length?

If the 150mm end needs to connect to another male fitting (e.g. a 150mm bend), you will need a female coupler at that joint, since two male ends cannot be joined directly.

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