Drum Pump Product

Overview

A drum pump (barrel pump) empties 200-litre drums, IBCs, and carboys from the top bung opening, replacing the dangerous practice of tipping a quarter-tonne drum to pour from it. The machine is two separable pieces: a hand-held Motor Head and a long Immersion Tube that reaches the drum bottom. One motor can drive a rack of different tubes — polypropylene for acids and alkalis, PVDF for concentrated oxidisers, stainless steel for solvents and flammables — so a single drive serves an entire chemical store. Typical performance is up to 200 L/min and 20 m head, enough to empty a drum in about ninety seconds.

How it works

The Motor Head contains a series-wound universal motor: a wound Rotor Assembly running inside the Stator Assembly field at up to 10,000 rpm, fed through a pair of Carbon Brush contacts and cooled by a shaft-mounted Cooling Fan. The armature rides on two Ball Bearing sets inside the splash-protected Motor Housing Shell. High speed is the point: it lets a very small impeller make useful head, which keeps the whole wetted end slim enough to pass a 2-inch bung.

Torque passes through the Quick-Release Coupling, where a knurled Coupling Hand Nut clamps the tube and a Drive Dog engages the Shaft Socket on the tube's inner shaft — no tools, a few seconds to swap tubes. Inside the Outer Tube, the Inner Shaft runs the full tube length, steadied every few hundred millimetres by a PTFE Shaft Bushing. At the foot, the Impeller — an open axial rotor about 38 mm across — sits in the Suction Foot behind a slotted Foot Strainer. It throws liquid up the annulus between shaft and tube to the Discharge Spout, through the Discharge Hose, and out the trigger-operated Hand Nozzle.

Sealless tubes are standard for most chemicals: the liquid simply drains back when the pump stops. Where vapours are aggressive or the liquid must not contact the upper shaft, a Tube Shaft Seal makes the tube gas-tight.

Mounting and control

The pump hangs in the drum on the Drum Adapter. Its polypropylene Bung Adapter threads into the standard 2-inch buttress bung, the Adapter Seal limits vapour escape, and the sliding Depth Collar sets how close the Suction Foot rides to the drum bottom — close enough to strip the drum nearly dry, leaving residues of under 100 mL with an angled foot.

Electrically, the head carries a 5 m oil-resistant Power Cord, a splash-protected Rocker Switch with low-voltage release (the pump cannot restart by itself after a power cut — a requirement for unattended safety), and a triac Speed Control Board that phase-angle-modulates the universal motor for stepless flow control. A Thermal Fuse in the windings protects against stall and blocked-rotor overheating.

Variants

The centrifugal-impeller tube described here handles thin liquids to roughly 1,000 mPa·s. For honey, resins, and greases up to 100,000 mPa·s, the same motor heads drive progressive-cavity tube ends with a helical rotor in an elastomer stator. Air-motor versions replace the electric head where compressed air is the preferred utility, and ATEX-certified sets with conductive tubes, earthing cables, and gas-tight seals are mandatory for flammables: a stainless tube, an explosion-proof motor, and bonding clamps between pump, drum, and receiving vessel prevent static ignition during solvent transfer.

Selection

Tube material is chosen against a chemical resistance table for the exact concentration and temperature: polypropylene covers most acids and alkalis to 50 °C, PVDF extends to concentrated nitric and chromic acid at 100 °C, stainless 316 covers solvents, and Hastelloy C handles the worst oxidising chlorides. Tube length matches the container — 1,000 mm for a standard 200 L drum, 1,200 mm for IBCs. Sizing errors show up fast at 10,000 rpm, so manufacturers publish viscosity and density derating curves; running a thin-liquid impeller in 5,000 mPa·s product simply stalls the flow while the motor overheats.