Round Spiral Duct
Fabricated round spiral ductwork in galvanised steel for HVAC distribution systems.
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Duct & Accessories
VCDs (Volume Control Dampers)
Opposed and parallel blade dampers for balancing airflow across a distribution network — with a locking quadrant that holds its setting.
Part of our HVAC & MEP service line — we supply, install and maintain it, not just sell it.
Overview
What it does.
A ventilation system is only balanced if it stays balanced. Dampers are what let a commissioning engineer set the design flow at each branch, and a locking quadrant is what stops that setting drifting the first time someone leans on the duct.
Opposed blade dampers give better control authority across the middle of their range, which is where balancing actually happens. Parallel blade is adequate for simple shut-off duty and cheaper, and we will say which one the job needs.
Gallery
What it looks like.
Representative units and components. Configuration, finish and connection sizes are built to the order — these show the range, not a fixed model.
Specification
The numbers.
Sizes, materials and duty are confirmed against your drawing and a site survey before quotation — nothing here is a fixed catalogue entry.
Technical
| Blade action | Opposed or parallel |
|---|---|
| Sizes | Rectangular and circular, made to duct size |
| Operation | Manual locking quadrant or motorised actuator |
| Blade seals | Optional for low-leakage duty |
| Frame | Flanged or slip-in |
Indicative figures. Final specification is confirmed against your duty and site survey at quotation.
Materials of construction
| Frame and blades | Galvanised steel |
|---|---|
| Bearings | Nylon or bronze |
| Seals | EPDM |
| Options | Aluminium or stainless construction |
Selection
Where it fits.
Applications
- System balancing
- Branch flow control
- Zone isolation
- Motorised control from a BMS
Options & accessories
Motorised actuatorLow-leakage blade sealsAluminium constructionExtended spindle for insulated duct
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Panel, bag, and HEPA-grade filters for HVAC systems — all standard and custom sizes available.
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Breakdown response and planned maintenance, Kingdom-wide
Seven service lines. One engineering team. Tell us your load, site and timeline — we will come back with a costed proposal.