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Silicone Dust Caps


Technical Description

The Hanningfield Uni-Cap is a flexible silicone rubber seal which provides a cost-effective method for the dust-tight transfer or containment of powders.

By cutting a hole in the centre of the cap, a dust-tight seal can be made with the penetrating spigot. This enables the contained charging of mills, tablet presses, vessels, drums / IBCs and almost any other item of process equipment where charging / discharging can produce dust. After the charging process is complete, the cap (with hole) can be replaced with a cap (without hole), to seal off the inlet.

Available in 2.5″, 8″, 8″ (Tri-Clover profile), 10″, 12″ and 16″, the Uni-Cap is designed to be compatible with our range of stainless steel mounting rings. This allows the cap to be easily fitted or retro-fitted to any process.

As standard, the caps are manufactured from translucent silicone (FDA CFR 177.2600), although we can accommodate specific requirements for material (e.g. EPDM) or colour (e.g. blue) in dedicated batches to satisfy your application. We are also able to introduce new tooling for unlisted sizes upon request.

Typical Applications

  • Dust Tight Seal between Outlet and Inlet
    Dust Tight Seal between Outlet and Inlet

    Here the spigot of the outlet penetrates the undersized hole in the silicone cap, providing a dust tight seal.


Brochure Name Description Download Brochure
Uni-Cap Brochure Download PDF Brochure Download

Data Table

Dust Caps:

Criteria Unit 2.5″ 5″ 8″ 8″ T/C 10″ 12″ 16″
Diameter mm 60mm 127mm 200mm 200mm 250mm 315mm 400mm
in 2.5″ 5″ 8″ 8″ 10″ 12″ 16″
Height mm 33mm 35mm 40mm 25mm 36mm 32mm 32mm
Wall Thickness mm 8mm 10mm 10mm 10mm 10mm 9.5mm 9.5mm
Material Hardness shore 60 60 60 60 60 60 60
Max. Spigot Size mm 50mm 100mm 150mm 150mm 200mm 265mm 350mm
Part Number 736564 736584 736571 736561 736565 736567 736572
Standard Material Translucent Silicone (FDA CFR 177.2600)

Mounting Rings:

Criteria Unit 2.5″ 5″ 8″ 8″ T/C 10″ 12″ 16″
Outside Diameter mm 60mm 127mm 204mm N/A 250mm 318mm 404mm
Height mm 50mm 50mm 50mm N/A 50mm 50mm 50mm
Wall Thickness mm 2mm 2mm 2mm N/A 2mm 2mm 2mm
Part Number 735688 750406 735689 N/A 735690 735691 735692
Standard Material 316L stainless steel (1.4404)



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