Hydraulic Ball Tube Expansion System (Polymer/Steel Ball)

This system expands heat-exchanger tubes against their fins by hydraulically pushing a ball — polymer or cemented-carbide steel — through the full length of the tube, rather than driving a rod through in steps. It's supplied as two linked stages: a BSB tube-end flaring system and a BE ball-expansion system. BSB tube-end flaring: one tube-end forming tool (BS series) plus a hydraulic power unit. The tool is sized to the tube's outer diameter, maximum wall thickness and required flaring depth, and is machined from heat-treated stainless steel for long service life. In use, the tube is inserted into the flaring tool and connected to the power unit; hydraulic pressure closes the tool's clamping jaws on the tube's outer wall while an internal piston rod extends outward, pressing an expansion ball into the tube end to form a flared, bell-mouth shape — this sets the insertion dimension for the expansion stage that follows. Tube outer-diameter roundness should conform to NB/T47019.1 Clause 6.6.1, with wall-thickness tolerance of -0.05mm to 0. BE ball expansion: BE tooling plus an HPB high-pressure ball-expansion pump unit, rated to 50 MPa maximum working pressure. After the BS tool flares the tube end and the expansion ball is placed inside, the BE tool inserts into the tube and clamps its outer wall, sealing against the tool. Water pressure is then raised continuously until there's enough hydraulic force to push the ball the full length of the tube, expanding it outward against the fins in one continuous pass. Example tube configurations this system has been engineered for (ball material and size are matched to each tube, so treat these as representative, not a fixed spec): — Ø15.88×0.6mm austenitic stainless steel tube, 16.4mm fin hole, expanded to 16.48–16.6mm OD (0.08–0.2mm interference fit), with a Ø15.45mm steel ball. — Ø13.5×0.55mm 70/30 copper-nickel double-layer tube (inner tube plus a Ø15.87mm OD / 13.87mm ID outer sleeve, 1.0mm wall), 16.4mm fin hole, with a Ø13.35mm steel ball. — Ø20×0.79mm copper-alloy tube, 20.5mm fin hole, expanded to 20.58–20.7mm OD, with a Ø19.1mm steel ball. Before shipment, we ask for 15–20 sample tubes (1m each) plus fin samples to run pre-shipment testing on your exact material.