Funnel Flares Sleeves And Couplings

Published: February 15, 2021
by Jean Jones

This week our challenge was to make a simple funnel flare– 3” ID tube to a 4” ID tube. The trick was to do it without tooling. The cup manufacturer company wanted only three flares to put at cup entrance points of its pneumatic transport system.

Busada makes all kinds of flared tubing and belled tubing . . . hundreds of kinds . . . and we cater to our customer’s unusual needs. We flare and bell butyrate, polycarbonate, PETG, PVC and other thermoplastics. We also flare and bell our bends.

Pictured below: A Sleeved Bell Reducer: We do not recommend connecting tubing and bends with traditional couplings (as in PVC lines). Pneumatic conveyance systems need smooth connections, and the traditional PVC-type coupling joint can damage conveyance materials. Our Busada 200 Tubing maintains a .005 tolerance in wall thicknesses, so coupling with clear sleeves is clean and preferable. Pictured above is a solvent-welded sleeve on the flare side with four axial cuts on the sleeve side. The cuts allow for clamping of the sleeve on a straight tube or bend with hose clamps.

Finally, PVC reducing bushings remain an option. Besides losing transparency, the PVC funnel angle of 30° can bump and ding the conveyance material. Nevertheless, we can flare out tubing to pipe dimensions and bond to PVC.

PVC couplings and bells are fine for valve-stem protectors. Check our other blogs on bonding dissimilar plastics with heat and adhesion. Note here that on top of adhesives we recommend a set screw (sheet metal screw) that will bite into the butyrate wall.

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